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1
Lee, Mok Young, Woong Seong Chang, and Sook Hwan Kim. "A Comparison of Weld Properties with or without Filler Wire on Laser Welding of Magnesium Alloy for Car Industry." Materials Science Forum 580-582 (June 2008): 489–92. http://dx.doi.org/10.4028/www.scientific.net/msf.580-582.489.
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Magnesium alloys are becoming important material for light weight car body, due to their low specific density but high specific strength. However they have a poor weldability, caused by high oxidization tendency and low vapour temperature. In this study, the welding performance of magnesium alloy was investigated for automobile application. The material was rolled magnesium alloy sheet contains 3wt%Al, 1wt%Zn and Mg balance. The effects of filler wire addition was investigated on 2kW Nd:YAG laser welding. For the results, the mechanical properties of welded specimen were similar with base metal in laser welding with and without filler wire. The bridging ability was improved with filler wire without weld properties deterioration on laser welding of magnesium alloy.
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Keskitalo, Markku, and Kari Mäntyjärvi. "Yb:YAG Disc Laser Welding of Austenitic Stainless Steel Without Filler Material." Key Engineering Materials 410-411 (March 2009): 87–96. http://dx.doi.org/10.4028/www.scientific.net/kem.410-411.87.
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The laser weldability of austenitic stainless steel (ASS) is good because of the material’s high absorptivity and favourable microstructure. There can be a slight possibility of solidification cracking at high welding speeds and low Crekv/Niekv ratios. Test welds were welded with a Yb:YAG disc laser. The test material was 3.2 mm EN 1.4404 2H C700 type stainless steel plate which was work hardened by cold rolling. The test materials were welded with different heat inputs ranging from 0.024 kJ/mm to 0.12 kJ/mm and with 300 mm and 200 mm focal lengths. The weld seams were square-groove welded as butt weld without filler material. The edges of the groove were made by mechanical or laser cutting. The hardness profiles from cross-sections of the welds were measured with a Vickers microhardness tester using 200 g weight. The mechanical properties were tested with tensile tests. The welds were classified with radiographic verification by an accredited laboratory. A number of the welds were fatigue tested with a bending fatigue tester. The mechanical properties (Rp 0.2%, Rm) of the laser welds were almost the same as in the base material except at the highest heat input. In the radiographic classification, the welds which were welded to the laser-cut edge were classified as class B (accepted). The other welds were classified as class D or C (rejected). The main reasons for the rejection of welds made on mechanically cut edges were lack of penetration or undercut of the weld. A problem with mechanically cut edges, and hence the welds, is that they can be non-square and bent edge. Fatigue tests and tensile tests gave no evidence of solidification cracking in the microstructure of the solidified parts of the welds.
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Tušek, Janez, B. Taljat, Marco Hrženjak, and Damjan Klobčar. "Laser Grooving and Welding of Cracks Occuring at Dies for Die Casting." Materials Science Forum 539-543 (March 2007): 4059–62. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4059.
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The paper treats the application of laser to repair of cracks occurring at dies for die casting of non-ferrous metals (particularly aluminium, magnesium and their alloys). The first part describes a suitable laser unit enabling crack grooving and then welding. An Nd:YAG laser source is shown with its equipment for laser-beam transfer, control and directing of laser-beam focus. Dies for die casting are made of quality steels and are of very complex shape. As far as their repair is concerned this means that they are to be welded at their edges, corners, narrow gaps and vertical walls, i.e. in various positions and in various directions. In the second part the grooving technology is described, and in the third part laser welding of grooved cracks using a filler material, i.e., a thin welding wire. At the end some conclusions are drawn. It is stated that from the viewpoints of technology and economics, it is sensible to laser groove and then weld the thermal cracks with a suitable material. The filler material should have such a chemical composition that after welding a weld having adequate mechanical properties, without any additional heat treatment, is obtained.
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Landowski, M. "Influence of Parameters of Laser Beam Welding on Structure of 2205 Duplex Stainless Steel." Advances in Materials Science 19, no. 1 (March 1, 2019): 21–31. http://dx.doi.org/10.2478/adms-2019-0002.
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AbstractLaser welding is used in modern industry, having many advantages comparing to traditional welding technologies. Nowadays, industry sectors such as shipbuilding, automotive and aviation can’t be imagined without laser processing technologies. Possibility of increase of welded joint properties, autogenous welding and high level of process automation makes the technology of laser welding perspective part of the industry. Physical multidimensional processes complexity requires a deeper understanding of the impact of laser welding parameters on the quality of welded joints for industrial implementation. The paper presents results of microstructure investigations of laser beam welded stainless steel under various welding parameters. Welded joints was achieved by Ytterbium fiber laser type without the use of the filler material. Material for test was 2205 ferritic-austenitic duplex stainless steel (DSS) plates with thickness of 8 mm in delivery condition. The objectives of this research was to investigate influence of laser welding parameters on weld geometry of butt-welded joints. Investigations of bead shape revealed correlation between laser beam focus position and weld penetration depth.
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Popa, George, Dana Cristina Bratu, Maria Cristina Bortun, Vlad Florin Vinatu, Ioan Both, catalin-Petru Simon, Silvia-Izabella Pop, and Angela CodruȚa Podariu. "Tensile and Shear Breaking Force of the Joints Between Stainless-Steel Orthodontic Bands and Buccal Tube Attachments Joined by Laser and TIG Welding Without Filler Material." Materiale Plastice 56, no. 4 (December 30, 2019): 693–99. http://dx.doi.org/10.37358/mp.19.4.5255.
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Orthodontic appliances usually require the joining of different stainless-steel parts in order to achieve adequate control over tooth movement during the active treatment. The aim of this study was to assess the tensile and shear breaking force of the joints between forty orthodontic bands and forty attachments (buccal tubes), joined by laser and TIG welding, without filler material. For the laser welding technique, we used an XXS Laser (OROTIG) welding unit and for the TIG welding technique, a PUK D2 (LAMPERT) welding unit. The tensile and shear breaking force of the welded joints was determined using the Z010 Zwick/Roell testing machine. The independent-samples t-test showed statistically significant differences between the laser and TIG groups for both the tensile and the shear breaking force tests, the laser welded samples having better mechanical strength than the TIG welded samples. For practical use, under normal loading forces, both techniques are suitable for this particular application in orthodontics. In patients with parafunctional habits, that could develop higher bite forces, the failure of the welded joints might occur if the welding surface is not increased, especially for the TIG welding technique.
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Ghiban, Alexandru, Mihai Buzatu, Cristina Maria Bortun, Brandusa Ghiban, and Nicolae Serban. "Laser Welding Optimization Procedure Applied to Cobalt Alloys for Removable Partial Dentures." Advanced Materials Research 1114 (July 2015): 272–77. http://dx.doi.org/10.4028/www.scientific.net/amr.1114.272.
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Optimization of fractured or destroyed removable partial dentures realized from CoCrMo alloys are possible due to modern welding equipments. The aim of study was to offer the processing and welding optimal parameters for some long lasting prosthetic pieces. There are investigated two cobalt based alloys, used for dental applications, types CoCrMo. Laser welding equipments was a Mini Laser XXS (Orotig Italia) and the tested samples were welded in butt joint, without filler material. There are presented in comparison results concerning macro and micro structural analysis made on stereomicroscope OLYMPUS and Reichert microscope. Finally a correlation between different welding parameter values and structural features was made.
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Ghiban, Alexandru, Brandusa Ghiban, Cristina Maria Bortun, and Mihai Buzatu. "Structural Analysis of the Laser Welding Co-Cr-Mo-(Ti) Alloys for Removable Partial Dentures." Key Engineering Materials 638 (March 2015): 91–97. http://dx.doi.org/10.4028/www.scientific.net/kem.638.91.
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Optimization of fractured or destroyed removable partial dentures realized from CoCrMo alloys are possible due to modern welding equipments. The aim of study was to offer the processing and welding optimal parameters for some long lasting prosthetic pieces made of a new alloy from the system CoCrMoTi. Laser welding equipments was a Mini Laser XXS (Orotig Italia) and the tested samples were welded in butt joint, without filler material. There are presented in comparison results concerning macro and micro structural analysis made on stereomicroscope and microscope type OLYMPUS. Finally a correlation between different welding parameter values and structural features was made for the new dental cobalt alloy.
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Réka Fábián, Enikő. "Laser Welding Parameters Effect on the Weld Metals Properties at Duplex Stainless Steels." Advanced Technologies & Materials 43, no. 2 (December 15, 2018): 7–13. http://dx.doi.org/10.24867/atm-2018-2-002.
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Nd: YAG laser welding of duplex stainless steels as 2205, LDX 2101, 2304, LDX 2404 grades were performed with and without addition materials. As additional material were used Metco 41C high nickel contain powder and 22 9 3 NL filler wire, conventional used for standard duplex stainless steels. The mechanical and corrosion properties of duplex stainless steels welds are dependent on microstructure and chemical composition. The additional materials favourable effects on mechanical properties were observed. The best pitting corrosion resistance were observed at specimens welded with wire addition.
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Sołtysiak, Robert, Tomasz Giętka, and Agnieszka Sołtysiak. "The effect of laser welding power on the properties of the joint made of 1.4462 duplex stainless steel." Advances in Mechanical Engineering 10, no. 1 (January 2018): 168781401775194. http://dx.doi.org/10.1177/1687814017751949.
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The butt welding of 1.4462 (2205) duplex stainless steel plates with thickness of 4 mm under various welding parameters was achieved by Nd:YAG laser type without the use of the filler material. Welding parameters such as welding power (kW) and the focus distance from the joint surface (mm) were changed. The Ar 5.0 protective gas flow and welding speed were the same for all the tests and were 20 L/min and 0.5 m/min, respectively. The weld shape, weld macrostructure, microstructure, strength and hardness, and the content of the ferrite in the weld zone, heat-affected zone, and base metal were emphatically investigated. The test results showed that increase in laser power increases the weld zone area. For the weld samples, a better ferrite/austenite ratio was obtained by focusing the laser beam on the sheet surface. Furthermore, the largest elongation from strength test has been observed for the weld samples made with laser power of 2.0 kW.
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Laukant, H., C. Wallmann, M. Korte, and Uwe Glatzel. "Flux-Less Joining Technique of Aluminium with Zinc-Coated Steel Sheets by a Dual-Spot-Laser Beam." Advanced Materials Research 6-8 (May 2005): 163–70. http://dx.doi.org/10.4028/www.scientific.net/amr.6-8.163.
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Joining of iron with aluminium in the liquid phase is complicated due to the formation of brittle intermetallics within Fe-Al melts. In this work we present the technology of a laser weldingbrazing (LWB) process to join zinc-coated steel and aluminium sheets in an overlap geometry. The process is divided into welding of the aluminium sheet and brazing of filler material and molten aluminium sheet onto the zinc-covered steel sheet to avoid the liquid stage of iron. It is possible to join those materials with a single laser beam. However, with a second laser beam, the melt flow can be controlled more effectively and the wetting behaviour can be improved by preheating the zinc-covered steel sheet surface. This is beneficial since the process works without any flux agent. Wetting lengths increase by using this technique and generate a joint that exceeds the tensile strength of the base material. Due to the zinc cover on the steel sheet there are two possible filler materials that have miscibility with zinc as well as aluminium. Zinc based filler materials have the advantage of a lower melting point and thus lower process temperatures. And aluminium based filler wires result in more ductile brazed seams, making it possible to deform such joints in a later application as tailored blanks.
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Carrizalez-Vazquez, M. A., and G. Y. Pérez-Medina. "Effect of Laser Welding Sequences on Residual Stresses and Distortion of DP600 Steel Joints." MRS Advances 4, no. 63 (2019): 3441–51. http://dx.doi.org/10.1557/adv.2019.415.
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ABSTRACTDifferent materials have been welded by laser beam. This process allows to obtain high quality welds with lower thermal effect. Laser beam welding produces narrow and high penetration welds without filler material. However, this process modifies the mechanical and microstructural properties of the welded joints. Therefore, this is currently a research topic, mainly using Advanced High Strength Steel (AHSS). These materials are used in the automotive industry. As a result, it is important to study the thermometallurgical and mechanical behavior of welded steels. In addition, a tool used to approximate the thermal effect in the fusion zone (FZ) and heat affected zone (HAZ) has been the computational numerical simulation. In this work, two butt joints of DP600 steel plates of 200 mm x 150 mm and 2 mm thickness with different welding sequences were simulated using the SYSWELD finite element software. The results of both coupons were compared and it was determined that the distortion and residual stresses decreased in the second coupon by applying a different welding sequence with equal heat input.
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Li, Min, Zhuguo Li, Yong Zhao, Hao Li, Yuhua Wang, and Jian Huang. "Influence of Welding Parameters on Weld Formation and Microstructure of Dual-Laser Beams Welded T-Joint of Aluminum Alloy." Advances in Materials Science and Engineering 2011 (2011): 1–6. http://dx.doi.org/10.1155/2011/767260.
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This paper focused on the welding 1.8 mm thick 6061 aluminum alloy plates in T-joint form using dual lasers that introduced by a Nd: YAG laser and a CO2laser with 4043 aluminum filler wire. The effects of welding parameters on the T-joint weld appearance, microstructure and the joint mechanical properties were studied systematically, The influence of welding parameters included the distance between two laser beams, welding speed, laser power and the laser beam offset toward the stringer. The weld appearance, microstructure, hardness of the joint were evaluated by optical microscope and micro-hardness test. A monotonic quasi-static tensile test was conducted by a self-made clamping device to obtain the tensile property of welded joints. At the optimized parameters, the welded T-joint showed good weld appearance without macro defects; the micro hardness of welds ranged from 75 to 85 HV0.3, and the tensile strength was about 254 MPa with the fracture at the heat affected zone on the stringer side.
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Mitelea, Ion, Corneliu Marius Crăciunescu, Ciprian Pavel Lucian, and Ion Dragoş Uţu. "Microstructure and mechanical properties of 6082-T6 aluminum alloy–zinc coated steel braze-welded joints." Materials Testing 63, no. 8 (August 1, 2021): 721–27. http://dx.doi.org/10.1515/mt-2020-0117.
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Abstract The laser braze-welding technique was aimed to join a low alloyed zinc coated steel used in automotive industry, with a deformable, aging hardenable aluminum alloy from the 6xxx series using as filler material a AlSi12 wire. The heterogeneous joint was obtained by welding of aluminum alloy with the filler wire and by brazing of molten aluminum alloy together with the filler wire on the surface of a zinc coated steel which remained in solid state. The results showed that by using a proper heat input, the zinc coated steel was brazed without a melting process by the aluminum alloy which was in liquid state. On the interface between the zinc coated steel and the welded seam, a thin layer (the thickness was 6 to 8 μm) formed consisting of star (Al-Fe-Si) or needle shape (Mg-Al-Fe-Mn) intermetallic phases.
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Banerjee, Amit Jyoti, Manoja Kumar Biswal, A. K. Lohar, H. Chattopadhyay, and Naga Hanumaiah. "Review on experimental study of Nd:YAG laser beam welding, with a focus on aluminium metal matrix composites." International Journal of Engineering & Technology 5, no. 3 (August 26, 2016): 92. http://dx.doi.org/10.14419/ijet.v5i3.5984.
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The demand for high performance materials particularly in aviation and automobile industries gradually increases, CO2 and Nd: YAG lasers are becoming most popular in processing these advanced materials. In this context, one of the most important process is joining by welding. It has been a constant endeavour by researchers to explore various methods and techniques to enhance the process efficiency of autogenous Nd: YAG laser welding of various materials i.e. without any filler materials. In this work, we present a comprehensive review of major research findings for the last decades or so, obtained by researchers about the effect of process parameters on autogenous laser beam welding (LBW) process performance. Main objective of such experimental research was to improve laser weld quality such as tensile strength, weld micro structure, heat affected zone (HAZ), weld penetration etc. In this paper, discussions are also made about different parameter optimisation techniques, design of experiments (DOE), modelling and simulation techniques, adopted by different researchers to achieve optimum weld quality. This review tries to bring out a foresight for direction of further research needed in this field.
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Sahul, Miroslav, Martin Sahul, Matej Pašák, and Milan Marônek. "ANALYSIS OF THE PROPERTIES OF AW2099 ALUMINIUM-LITHIUM ALLOY WELDED BY LASER BEAM WITH AW5087 ALUMINIUM-MAGNESIUM FILLER MATERIAL." Acta Polytechnica 59, no. 6 (December 31, 2019): 580–86. http://dx.doi.org/10.14311/ap.2019.59.0580.
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EN AW2099 aluminium lithium alloy, 2.0mm in thickness, was used as an experimental material. EN AW2099 belongs to the 3rd generation of aluminium lithium alloys. The third generation was developed to improve the disadvantages of the previous generation, such as anisotropy in mechanical properties, low fracture toughness, corrosion resistance and resistance to fatigue crack growth, as well. Aluminium magnesium 5087 filler wire with a diameter of 1.2mm was used for the welding. Crack free weld joints were produced after an optimization of welding parameters. The microstructure of weld metal and mechanical properties of weld joints were investigated. Equiaxed zone (EQZ) was observed at the fusion boundary. The character of grains changed in the direction towards the weld centre, from the columnar dendrite zone to equiaxed dendrite zone in the weld centre. The microstructure of the weld metal matrix consisted of -aluminium. Alloying elements enrichment was found at the inter-dendritic areas, namely copper and magnesium. The microhardness decrease in the weld metal due to a dissolution of strengthening precipitates was measured. The microhardness was slightly higher in comparison to a weld produced by a laser welding without a filler material. The tensile strength of the weld joint reached around 67% of the base material’s strength and the fracture occurred in the weld metal.
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Barbieri, Giuseppe, Francesco Cognini, Massimo Moncada, Antonio Rinaldi, and Gabriele Lapi. "Welding of Automotive Aluminum Alloys by Laser Wobbling Processing." Materials Science Forum 879 (November 2016): 1057–62. http://dx.doi.org/10.4028/www.scientific.net/msf.879.1057.
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The scope of this paper is to examine the improvement from laser welding by an innovative beam wobbling head towards the welding of tailored blanks parts, widely used in automotive to develop different stiffness aluminum components. For this purpose, butt joints and overlapping joints were produced from sheets made out of two industrial grades, i.e. AA-6082 T6 and AA-5754 H111 of different thickness. The technique was evaluated both with and without the use of a filler wire (AA-5556). The qualification of the welding process encompassed Non Destructive Testing (NDT) and mechanical testing. The results indicate that butt joints tend to fail within the base material (BM) of sheet with smaller thickness. On the contrary, the shear tests on lap joints highlighted a rupture mode occurring in the heat affected zone (HAZ) of the thin sheet. Remarkably, the wobbling process generally allows avoiding porosity when combined with an optimized set of welding parameters. Yet, a residual porosity was always detected in lap joints, varying with the size of the fused zone.
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van der Stelt, A. A., T. C. Bor, H. J. M. Geijselaers, R. Akkerman, and A. H. van den Boogaard. "Cladding of Advanced Al Alloys Employing Friction Stir Welding." Key Engineering Materials 554-557 (June 2013): 1014–21. http://dx.doi.org/10.4028/www.scientific.net/kem.554-557.1014.
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Friction stir welding (FSW) is a relatively new solid-state joining technology for metals. It shows no solidification-related joint imperfections which makes it utmost suitable for hard-to-weld highly alloyed aerospace aluminium grades, like AA 2xxx and AA 7xxx. These alloys are often cladded with a thin layer of pure aluminium for corrosion protection. Friction stir welding of such materials requires removal of the clad layer prior to welding to prevent weakening of the joint by the soft clad material. This leaves the welded region vulnerable to corrosion after the joining process. Post-weld restoration of the clad layer is required to restore the protective action of the clad layer and as such to enhance the life expectancy of the welded construction. In this work the deposition of thin layers of pure aluminium on AA 2xxx and AA 7xxx alloys is studied employing an innovative FSW tool. The tool shoulder is equipped with strategically placed internal channels that allow delivery of filler type of material into the weld zone. Depending on the channel architecture used, filler material can be deposited on top of the work piece surface and/or mixed with the work piece surface region. The cladding is done in the solid state avoiding many problems with solidification and interface reactivity often observed with other surface modification techniques, such as laser surface engineering, plasma spraying or casting. Here, the filler material is deposited on top of the work piece; the modified tool is not equipped with a tool pin. The work comprises an in depth study of the influence of process conditions on the microstructural changes in the underlying work piece and on the quality of the bonding of the clad material (99.5 % aluminium) to the work piece material. Apart from the usual process conditions, such as tool rotation speed, translation speed, down force and tool angle also the delivery pressure and rate of the filler supply system can be varied. The influence of the usual process conditions on the microstructure of the underlying work piece is similar to that observed with “traditional” FSW. Changes in hardness can be related to the amount of heat generated by the welding process. Shape and dimensions of the microstructural zones found are typical for welds made without a tool pin. The effect of the small amount of clad material deposited on top of the work piece on the temperature distribution is small. The amount of heat required to heat it up is negligible to the heat required to heat up the work piece and the tool. The quality of the bonded clad layer is dependent on the amount of heat and plastic deformation generated at the interfaces between the tool, the filler material and the work piece. Tool angle, tool shape and supply rate of the filler supply system determine the layer thickness.
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Alnusirat, Walid, Alexandr Salenko, Olga Chencheva, Sergii Shlyk, Irina Gusarova, and Alexandr Potapov. "About the possibility of application of laser vacuum welding for the integration of elements of heat-protective structures from powder materials." EUREKA: Physics and Engineering, no. 5 (September 13, 2021): 88–99. http://dx.doi.org/10.21303/2461-4262.2021.001998.
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The results of studying the process of laser vacuum welding of elements of heat-shielding panels made of heat-resistant dispersion-strengthened powder materials Ni-20Cr-6Al-Ti-Y2O3 of increased strength are presented. Such materials can be used to create ultralight heat-shielding panels, which are systems integrated on the surface of aircraft from typical modules of a cellular structure.
Technical solutions of heat-insulating modules are considered, which are a cellular (honeycomb) structure consisting of two plates with a thickness of 0.1 to 0.14 mm, inside which there is a thin honeycomb filler. It is shown that the small thickness of the plates and the complexity of integrating the elements into a single system significantly impair the formation of a strong connection of such elements and do not allow the direct use of the known methods of diffusion welding or vacuum brazing.
It has been established that laser welding of elements of heat-shielding structures in vacuum provides satisfactory strength of the structure of the heat-shielding element as a whole. Local heating at certain points prevents deformation of the parts to be joined during the welding process. The use of a pulsed Nd:Yag laser with a power of 400–500 W, operating in the frequency range of 50–200 Hz, allows welding with or without a filler powder. It was found that the use of filler additives practically does not affect the mechanical properties of the welded joint, however, it reduces the melt zone, while increasing the density of the welded joint.
Based on the results obtained, it was concluded that it is possible to use laser vacuum welding for the integration of thin elements of heat-shielding modules. It is shown that a satisfactory joint strength is achieved by ensuring high cleanliness of the surfaces of elements before welding, maintaining a high vacuum (less than 10–2 Pa) and rational thermal loading of the surfaces of the elements to be integrated.
The use of the proposed process makes it possible to obtain a stronger and denser seam in comparison with the known methods of soldering multicomponent powder dispersion-strengthened materials
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Barbieri, Giuseppe, Francesco Cognini, Luciano Pilloni, Daniele Mirabile Gattia, and Claudio Testani. "15/15 Ti Stainless Steel Welding Process Optimization for GEN IV Nuclear Application in the GEMMA Project Frame." Materials Science Forum 1016 (January 2021): 262–67. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.262.
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This paper deals with activities carried out in the frame of GEMMA project on welded samples of 15/15 Ti stainless steel. The focus of GEMMA project has been on the investigation of material properties and associated welded joints for GEN IV nuclear plants. The RCC-MRx code uses the standard Base Metal Grade nomenclature (EN/ISO), but provides also additional specifications. Titanium stabilized “15-15Ti” stainless steel has been the primary choice for fuel cladding of current fast spectrum research reactor projects. The choice of cladding material is based on past experiences and the availability of material databases from similar steel grades proven in past sodium-cooled fast reactors programs [1-4]. On the basis of ENEA past experience, a strict specification has been written to realize a new heat treatment of this special stainless steel (SS). One of the main problems faced with this material is the high tendency to crack after the welding process. Several preliminary welding tests permitted to select TIG and laser welding processes for the 15/15 Ti SS. This fact because the main applications involve small thicknesses without filler material. The welding of the 15/15 Ti was performed using a fully automated TIG work station at ENEA CR-Casaccia. The base materials to evaluate the welding parameters were 15/15 Ti plates 100 X 170 X 3 mm welded under different shielding gas atmospheres and process parameters arrangements that permitted to obtain good quality joints avoiding catastrophic hot-cracking. The welded samples underwent a mechanical and metallographic characterization and the main results are here presented.
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Keskitalo, Markku, Kari Mäntyjärvi, and Toni Kiuru. "The Low-Cycle Fatigue Strength of Laser-Welded Ultra-High-Strength Steel." Key Engineering Materials 473 (March 2011): 281–89. http://dx.doi.org/10.4028/www.scientific.net/kem.473.281.
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The UUltra -high -strength (UHS) steels are used in booms, transport vechicles and other light weight structures. It is well -known that it is possible to achieve a strong weld statically, as the base material, by using laser welding as a weld method [1]. The design strength of the light weight structure is often rather high. In the case of booms and transport vechilevehicles, there can be very high dynamic forces in the structure. Therefore it is necessary to study how much fatigue stress the weld seam can resist and at the same time find the optimal welding parameters. The 4 mm bainitic-martensitic UHS steel was welded with laser without filler material to lasercut seam edges by using different weld parameters. Argon gas was blown by pipe onr coaxial nozzle near the key hole and through a 60 mm gas nozzle after the keyhole. Also, the root side of the weld was shielded with argon. The welds were tested by using the bending fatigue test. The test stresses were 800 MPa and 700 MPa. The fatigue strength results showed that with the laser welded seams, the number of cycles wereas about three times lower than with the base material. The fatigue strength was slightly better in welds which were welded with lower energy input. In the case of the weld seam which was welded with lowest energy input by using 300 mm optics, there was some incomplete penetration due to tooexcessively high surface roughness ofat the weld seam edges.
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Guo, Ning, Qi Cheng, Xin Zhang, Yunlong Fu, and Lu Huang. "Microstructure and Mechanical Properties of Underwater Laser Welding of Titanium Alloy." Materials 12, no. 17 (August 23, 2019): 2703. http://dx.doi.org/10.3390/ma12172703.
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Underwater laser beam welding (ULBW) with filler wire was applied to Ti-6Al-4V alloy. Process parameters including the back shielding gas flow rate (BSGFR) (the amount of protective gas flowing over the back of the workpiece per unit time), focal position, and laser power were investigated to obtain a high-quality butt joint. The results showed that the increase of BSGFR could obtain the slighter oxidation level and refiner crystal grain in the welded metals. Whereas the back shielding gas at a flow rate of 35 L/min resulting in pores in the welded metals. With the increasing of the heat input, the welded metals went through three stages, i.e., not full penetration, crystal grain refinement, and coarseness. Crystal grain refinement could improve the mechanical properties, however, not full penetration and pores led to the decline in mechanical properties. Under optimal process parameters, the microstructure in the fusion zones of the underwater and in-air weld metals was acicular martensite. The near the fusion zone of the underwater and in-air weld metals consisted of the α + α′ phase, but almost without the α′ phase in the near base metal zone. The tensile strength and impact toughness of the underwater welded joints were 852.81 MPa and 39.07 J/cm2, respectively, which approached to those of the in-air welded joints (861.32 MPa and 38.99 J/cm2).
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Betini, E. G., C. S. Mucsi, T. S. Luz, M. T. D. Orlando, M.-N. Avettand-Fènoël, and J. L. Rossi. "Effect of post-weld heat treatment on thermal diffusivity in UNS S32304 duplex stainless steel welds." Archives of Materials Science and Engineering 2, no. 88 (December 1, 2017): 49–58. http://dx.doi.org/10.5604/01.3001.0010.8039.
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Purpose: The thermal diffusivity variation of UNS S32304 duplex stainless steel welds was studied after pulsed GTA welding autogenous process without filler addition. This property was measured in the transverse section of thin plates after welding process and post-heat treated at 750°C for 8 h followed by air-cooling. Design/methodology/approach: The present work reports measurements of thermal diffusivity using the laser-flash method. The thermal cycles of welding were acquired during welding by means of k-type thermocouples in regions near the weld joint. The used shielding gas was pure argon and 98% argon plus 2% of nitrogen. The temperature profiles were obtained using a digital data acquisition system. Findings: It was found an increase of thermal diffusivity after welding process and a decrease of these values after the heat treatment regarding the solidified weld pool zone, irrespective of the welding protection atmosphere. The microstructure was characterized and an increase of austenite phase in the solidified and heat-affected zones was observed for post-weld heat-treated samples. Research limitations/implications: It suggests more investigation and new measurements about the influence of the shielding gas variation on thermal diffusivity in the heat-affected zone. Practical implications: The nuclear industry, especially, requests alloys with high thermal stability in pipes for power generation systems and safe transportation equipment’s for radioactive material. Thus, the duplex stainless steel grades have improved this stability over standard grades and potentially increase the upper service temperature reliability of the equipment. Originality/value: After heat treatment, the welded plate with 98%Ar plus 2%N2 as shielding gas presented a thermal diffusivity closer to the as received sample. By means of 2%-nitrogen addition in shielding gas during GTAW welding of duplex stainless steel may facilitate austenite phase reformation, and then promotes stability on the thermal diffusivity of duplex stainless steels alloys.
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del Prete, Antonio, Gabriele Papadia, Teresa Primo, and Emilia Mariano. "Development of Accurate Numerical Models for Bending of Aluminum Tailored Blanks." Key Engineering Materials 549 (April 2013): 205–12. http://dx.doi.org/10.4028/www.scientific.net/kem.549.205.
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Nowadays the main target in the automotive field is the realization of lightweight and safe components. In this way it is possible to reduce costs and improve fuel consumption and, at the same time, enhance passenger safety. The use of tailored blanks has increased considerably in the automotive industry. Tailored blanks are a combination of different thicknesses or different materials, obtained by welding together two or more blanks, used in particular in car body panels. A new requirement in the automotive sector is the application of aluminum tailored blanks. The main target of this paper is the development of accurate numerical models for bending tailored blanks made from thin aluminum sheets, joined by laser welding, without filler metal. The FE bending simulations have been carried out using an explicit solver. The accuracy of the numerical models has been estimated and improved through a comparison with the results from an experimental study. The experimental tests have been performed using bending testing equipment, designed and developed by the authors. Three different bending radii have been tested. Tailored blanks, used as specimens, have been made by laser welding of thin Al6061 sheets. The considered outputs, used for the numerical-experimental comparison, are the punch force and the bending angle. The experimental results have been compared with the numerical ones in order to verify the accuracy of the FE model related to thickness and radius variations.
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Jubera, Daniel, and Anna Gessmann. "Aluminium Welding Without Filler Material." ATZ worldwide 115, no. 4 (March 9, 2013): 68–71. http://dx.doi.org/10.1007/s38311-013-0049-z.
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Bhattacharya, Raktim, Nitesh Kumar, Nikhil Kumar, and Asish Bandyopadhyay. "A Study On The Effect Of Process Parameters On Weld Width And Heat Affected Zone Of Pulsed Laser Welding Of Dissimilar Transparent Thermoplastics Without Filler Materials In Lap Joint Configuration." Materials Today: Proceedings 5, no. 2 (2018): 3674–81. http://dx.doi.org/10.1016/j.matpr.2017.11.618.
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Berger, Stefan, and Michael Schmidt. "Laser Transmission Welding of CFRTP Using Filler Material." Physics Procedia 56 (2014): 1182–90. http://dx.doi.org/10.1016/j.phpro.2014.08.033.
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Naeem, Mohammed. "High Power Fiber Laser Welding with Filler Material." PhotonicsViews 16, no. 5 (October 2019): 51–55. http://dx.doi.org/10.1002/phvs.201900046.
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Tsibulskiy, I., M. Kuznetsov, and A. Akhmetov. "Effect of Welding Position and Gap between Samples on Hybrid Laser-Arc Welding Efficiency." Applied Mechanics and Materials 682 (October 2014): 35–40. http://dx.doi.org/10.4028/www.scientific.net/amm.682.35.
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Influence of welding position and gap between samples on efficiency of hybrid laser-arc welding (HLAW), geometry of melting zone and alloys of filler material depth penetration are presented in the publication. Studies were indicated that maximal efficiency (thermodynamic efficiency about 43%) was achieved at hybrid laser-arc welding in PG welding position. Efficiency at PA and PC welding positions were 31.8% and 33.8% accordingly. Researches were indicated that melting zone, depth penetration alloys of filler materials and efficiency of HLAW increase with increasing gap. Experiments were indicated, that depth penetrate of filler material alloys is 20 mm (gap 1 mm). Proportion of filler material in a top part of metal seam is 50%, in bottom part of metal seam is about 5%.
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Üstündağ, Ömer, Vjaceslav Avilov, Andrey Gumenyuk, and Michael Rethmeier. "Improvement of Filler Wire Dilution Using External Oscillating Magnetic Field at Full Penetration Hybrid Laser-Arc Welding of Thick Materials." Metals 9, no. 5 (May 23, 2019): 594. http://dx.doi.org/10.3390/met9050594.
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Hybrid laser-arc welding offers many advantages, such as deep penetration, good gap bridge-ability, and low distortion due to reduced heat input. The filler wire which is supplied to the process is used to influence the microstructure and mechanical properties of the weld seam. A typical problem in deep penetration high-power laser beam welding with filler wire and hybrid laser-arc welding is an insufficient mixing of filler material in the weld pool, leading to a non-uniform element distribution in the seam. In this study, oscillating magnetic fields were used to form a non-conservative component of the Lorentz force in the weld pool to improve the element distribution over the entire thickness of the material. Full penetration hybrid laser-arc welds were performed on 20-mm-thick S355J2 steel plates with a nickel-based wire for different arrangements of the oscillating magnetic field. The Energy-dispersive X-ray spectroscopy (EDS) data for the distribution of two tracing elements (Ni and Cr) were used to analyze the homogeneity of dilution of the filler wire. With a 30° turn of the magnetic field to the welding direction, a radical improvement in the filler material distribution was demonstrated. This would lead to an improvement of the mechanical properties with the use of a suitable filler wire.
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Banasik, Marek, Jerzy Dworak, and Sebastian Stano. "Laser welding with filler material in the form of a wire." Welding International 26, no. 7 (July 2012): 516–20. http://dx.doi.org/10.1080/09507116.2011.600004.
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Kim, Jaewoong, Jisun Kim, and Changmin Pyo. "A Study on Fiber Laser Welding of High-Manganese Steel for Cryogenic Tanks." Processes 8, no. 12 (November 25, 2020): 1536. http://dx.doi.org/10.3390/pr8121536.
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As the environmental regulations on ship emissions by the International Maritime Organization (IMO) become stricter, the demand for a ship powered by liquefied natural gas (LNG) is rapidly increasing worldwide. Compared to other materials, high-manganese steel has the advantages of superior impact toughness at cryogenic temperatures, a low thermal expansion coefficient, and a low-cost base material and welding rod. However, there is a limitation that the mechanical properties of a filler material are worse than those of a base material that has excellent mechanical properties. To solve these shortcomings, a basic study was performed to apply fiber laser welding with little welding deformation and no filler material to high-manganese steel. The relationship between laser welding parameters and penetration shapes was confirmed through cross-section observation and analysis by performing a bead on plate (BOP) test by changing laser power and welding speed, which are the main parameters of laser welding. In addition, the welding performance was evaluated through mechanical property tests (yield strength, tensile strength, hardness, cryogenic impact strength) of a welding part after performing the high-manganese steel laser butt welding experiment. As a result, it was confirmed that the yield strength of a high-manganese steel laser welding part was 97.5% of that of a base metal, and its tensile strength was 93.5% of that of a base metal.
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Mann, Vincent, Fabian Gärtner, Florian Hugger, Konstantin Hofmann, Felix Tenner, and Stephan Roth. "Influence of Surface Structured Filler Wires on Laser Beam Welding of Copper Alloys." Applied Mechanics and Materials 805 (November 2015): 171–79. http://dx.doi.org/10.4028/www.scientific.net/amm.805.171.
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Compared to steel, the required amount of energy for conventional welding of copper is higher, due to its higher thermal conductivity. This problem is mainly solved by preheating the work pieces or welding processes with high intensities such as laser beam welding. As the absorption of copper for infrared wavelengths, which are commonly used in industrial applications today, is typically low, the energy efficiency of the laser welding process is low. Besides this, if filler wires are used in order to increase the bridgeable width of joining gaps, the energy consumption of the process is further increased due to the additional amount of energy required to melt the filler material.As roughened surfaces of copper parts are known to increase absorption and consequently energy efficiency of laser beam welding without filler wires, this paper investigates the influence of surface structured filler wires on laser beam welding of copper alloys. Thus, the correlation between knurling geometries, absorption, molten volume and the welding result is investigated. For this reason, the welding result is evaluated by means of geometrical, electrical and mechanical weld seam properties e.g. seam width, weld reinforcement, area of cross-section, electrical resistance, tensile strength and strain.
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Rasmus, Milla, Kari Mäntyjärvi, and Jussi A. Karjalainen. "Small Batch Laser Welding Using Light Fasteners and Laser Tack Welding." Key Engineering Materials 473 (March 2011): 267–72. http://dx.doi.org/10.4028/www.scientific.net/kem.473.267.
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Laser welding is known for its low heat input compared to arc welding methods. This could enable laser welding of sheet metals with lighter fastening solutions and less time-consuming tack welding alternatives. A feasibility study was carried out to study four different corner joint types for 2 mm thick cold rolledcold-rolled steel sheet by using filler-free laser welding. The aim of the research was to get more experimental knowledge about the laser welding of corner joints. Also possible benefits concerning faster manufacturing times and smaller costs by developing fastening applications for small batch laser welding was to be studied in practice. The 170 mm long joints were welded without air gap or pressing. All corner joint types proved to be weldable with a continuous wave Yb:YAG diode-pumped disk laser. It was also found during the With the experiment it was also found out that laser welding enables the use of light and inexpensive fasteners such as magnetic holders in steadinstead of traditional clamps and fixturing. With some joint types, the insufficient fastening power of magnetic fasteners against distortions was compensated by making a spot-like laser tack weld toat the end of the weld before welding the actual seam. This showed that it is possible to make precise and small tack welds with a laser and to use laser -tacking in sheet metal assembly.
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Schultz, Villads. "Process Stability during Laser Beam Welding with Beam Oscillation and Wire Feed." Journal of Manufacturing and Materials Processing 3, no. 1 (February 1, 2019): 17. http://dx.doi.org/10.3390/jmmp3010017.
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Beam oscillation in laser material processing makes it possible to influence process behavior in terms of energy distribution, stability, melt pool dynamics and solidification. Within the setup presented here, the beam is oscillated transverse to the welding direction, and the filler wire is fed to the melt pool of a butt joint with an air gap. One advantage of this setup is the large gap bridging ability. Certain parameter sets lead to the so-called buttonhole welding method, which allows laser welding of smooth and nearly ripple-free seams. Observations showed a transition area between conventional keyhole and buttonhole welding in which the process is destabilized. Welds made with parameter sets from this area contain critical seam defects. Welding experiments with high-speed video recording and a simplified analytical model about the wire-beam interaction have helped to elucidate the mechanisms behind this. EN AW-6082 sheet material in 1.5 mm thickness and ML 4043 filler wire with 1.2 mm diameter were used. The investigations lead to the conclusion that partially melted wire segments result at certain parameter relations which hinder the formation of a buttonhole. If these segments are prevented, buttonhole welding occurs. In the transition area, these segments are very small and can lead to the detachment of a buttonhole, resulting in the named seam defects.
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El-Batahgy, A., and M. Kutsuna. "Laser Beam Welding of AA5052, AA5083, and AA6061 Aluminum Alloys." Advances in Materials Science and Engineering 2009 (2009): 1–9. http://dx.doi.org/10.1155/2009/974182.
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The present investigation was mainly concerned with characteristics of autogeneous laser butt welding of 2 mm thickness nonheat treatableAA5052-H12,AA5083-H12 and 2 mm, 3 mm thickness heat treatableAA6061-T6aluminum alloys. The effect of laser welding parameters, surface cleaning, filler wire addition, and backing strip on quality of laser welded joints was clarified using 5 kW laser machine. It was found that all the investigated alloys showed tendencies for porosity and solidification cracking, particularly, at high welding speed (4 m/min). Porosity was prevented by accurate cleaning of the base metal prior to welding and optimizing the flow rate of argon shielding gas. Solidification cracking was avoided through two different approaches. The first one is based on the addition of filler metal as reported in other research works. The other new approach is concerned with autogeneous welding using a backing strip from the same base metal, and this could be applicable in production. Preventing solidification cracking in both cases was related mainly to a considerable decrease in the stress concentration at the weld metal center as a result of improving the fusion zone profile. The implementation of the new approach could help in producing weldments with a better quality due to the absence of the filler metal, which is known as a source for hydrogen-related porosity. It can also have a positive economic aspect concerning the manufacturing cost since welding is done without the addition of filler metal. Not only quality and economic positive aspects could be achieved, but also high productivity is another feature since high quality autogeneous weldments were produced with high welding speed, 6 m/min. Hardness measurements and tensile test of AA6061 alloy welds indicated a remarkable softening of the fusion zone due to dissolution of the strengthening precipitates, and this was recovered by aging treatment after welding. For alloys AA5052 and AA5083, softening of the fusion zone due to the loss of its work-hardened condition was much less in comparison with AA6061 alloy.
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Kästner, Christian, Matthias Neugebauer, Klaus Schricker, and Jean Pierre Bergmann. "Strategies for Increasing the Productivity of Pulsed Laser Cladding of Hot-Crack Susceptible Nickel-Base Superalloy Inconel 738 LC." Journal of Manufacturing and Materials Processing 4, no. 3 (August 29, 2020): 84. http://dx.doi.org/10.3390/jmmp4030084.
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A novel repair strategy based on decoupled heat source for increasing the productivity of wire-assisted pulsed laser cladding of the γ’-precipitation strengthening nickel-base superalloys Inconel 738 low carbon (IN 738 LC, base material) and Haynes 282 (HS 282, filler material) is presented. The laser beam welding process is supported by the hot-wire technology. The additional energy is utilized to increase the deposition rate of the filler material by increasing feeding rates and well-defining the thermal management in the welding zone. The simultaneous application of laser pulse modulation allows the precise control of the temperature gradients to minimize the hot-crack formation. Accompanying investigations such as high-speed recordings and numerical simulations allow a generalized statement on the influence of the adapted heat management on the resulting weld seam geometry (dilution, aspect ratio and wetting angle) as well as the formation of hot-cracks and lack of fusion between base and filler material. Statistical analysis of the data—the input parameters like laser pulse energy, pulse shape, hot-wire power and wire-feeding rate in conjunction with the objectives like dilution, aspect ratio, wetting angle and hot-cracking behavior—revealed regression functions to predict certain weld seam properties and hence the required input parameters.
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Vollert, Florian, Jonny Dixneit, Jens Gibmeier, Arne Kromm, Thomas Buslaps, and Thomas Kannengiesser. "In Situ EDXRD Study of MAG-Welding Using LTT Weld Filler Materials under Structural Restraint." Materials Science Forum 905 (August 2017): 107–13. http://dx.doi.org/10.4028/www.scientific.net/msf.905.107.
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Welding using low transformation temperature (LTT) filler materials is an innovative approach to mitigate detrimental welding residual stresses without cost-intensive post weld-treatments [1, 2]. Due to the local generation of compressive residual stresses in the weld line by means of a delayed martensite transformation a significant enhancement of the cold cracking resistance of highly stressed welded components can be expected. For the effective usage of these materials a deeper understanding of the microstructural evolution inside the weld material is necessary to determine the complex processes that cause the residual stress formation during welding. Solid-state phase transformation kinetics and the evolution of strain in LTT weld filler materials are monitored in-situ at the instrument ID15A@ESRF in Grenoble. The transferability to real components is implemented by using a realistic MAG welding process under consideration of structural restraint. During welding of multilayer joints, the phase transformation and phase specific strain evolution of each individual layer is investigated in transmission geometry by means of energy-dispersive X-ray diffraction EDXRD using high energy synchrotron radiation with a counting rate of 2.5 Hz. The measurement results of a 10% Cr / 10% Ni LTT weld filler are compared to data monitored for the conventional weld filler material G89. The in-situ data clearly indicate a strong effect on the local strain evolution and the formation of compressive strain. This results from the restraint volume expansion during the postponed austenite to martensite transformation of the LTT weld filler, which counteracts the thermal shrinkage. In contrast, for the conventional weld filler material the thermal contraction strains lead to tensile residual strain during welding. Furthermore, the results of in-situ observation during welding show that the transformation kinetic is dependent on the welding sequence.
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Zhang, Yan, YanKun Chen, JianPing Zhou, DaQian Sun, and HongMei Li. "Laser welding-brazing of alumina to 304 stainless steel with an Ag-based filler material." Metallurgical Research & Technology 118, no. 1 (December 4, 2020): 104. http://dx.doi.org/10.1051/metal/2020086.
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In this paper, laser welding-brazing of 304 stainless steel (SS) and Al2O3 ceramic dissimilar metal material was carried out. The results showed that the SS and Al2O3 were joined by melting filler metal when the laser was focused on the SS side of the joint. One process was one pass welding involving creation of a joint with one fusion weld and one brazed weld separated by remaining unmelted SS. When laser beam was focused on the SS plate 1.5 mm, SS would not be completely melted in joint. Through heat conduction, the filler metal (68.8 wt.% Ag, 26.7 wt.% Cu, 4.5 wt.% Ti) melting occurred at the SS-Al2O3 ceramic interface. A brazed weld was formed at the SS-Al2O3 ceramic interface with the main microstructure of Cu[s.s.] + Ag[s.s.], Ti2Cu + TiFe and Ag + AlCu2Ti. The joint fractured in reaction layer at the ceramic side with the maximum tensile strength of 74 MPa.
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Hellberg, S., S. Wagner, D. Martin, and S. Böhm. "Micro Electron Beam Welding of the hybrid material combination Nitinol and stainless steel without filler material." Journal of Physics: Conference Series 1089 (September 2018): 012003. http://dx.doi.org/10.1088/1742-6596/1089/1/012003.
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Ploshikhin, Vasily, A. Prikhodovski, A. Ilin, C. Heimerdinger, and F. Palm. "Computer Aided Development of the Crack-Free Laser Welding Processes." Key Engineering Materials 353-358 (September 2007): 1984–94. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1984.
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The present paper describes the new methodology used for the development of the crackfree welding processes. The presented approach is based on the accurate experimental observations on binary Al-Si alloys, which clearly demonstrate that the crack initiation is a result of the accumulation of macroscopic tensile strain in a microscopic intergranular liquid film of segregates at the final stage of the weld metal solidification. The numerical model takes into account the effects of strain accumulation as well as the influence of thermo-dynamical and thermo-mechanical properties of the welded material. The new approach provides a clear phenomenological interrelation between the cracking susceptibility, parameters of the welding process and properties of the base and filler material. It is successfully applied for development of technological means for elimination of the solidification cracking during welding of aluminium alloys AA6056, such as a multi-beam welding.
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Berger, Stefan, Florian Oefele, and Michael Schmidt. "Laser transmission welding of carbon fiber reinforced thermoplastic using filler material—A fundamental study." Journal of Laser Applications 27, S2 (February 2015): S29009. http://dx.doi.org/10.2351/1.4906391.
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Park, Young Whan, and Dong Yun Kim. "Optimization of Laser Welding Parameters in Aluminum Alloy Welding and Development of Quality Monitoring System for Light Weight Vehicle." Materials Science Forum 706-709 (January 2012): 2998–3003. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.2998.
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In this paper laser welding AA5182 of aluminum alloy with AA5356 filler wire were performed with respect to laser power, welding speed, and wire feed rate. The experiments showed that the tensile strength of the weld was higher than that of the base material under sufficient heat input conditions. A genetic algorithm was used to optimize process parameters which were the laser power, welding speed, and wire feed rate. To do that, a fitness function was formulated, taking into account weldability and productivity. A factor for the weldabilty used tensile strength estimation model which was made by neural network, and as the productivity, welding speed, and wire feed rate were used. Weld monitoring system for aluminum laser welding with filler wire was constructed through the optical sensors to measure the plasma light intensity. Relationship between monitoring signal and plasma and keyhole behavior according to welding condition was analyzed and it was found that sensor signal could express the information for weld quality. Weld quality estimation algorithm was formulated fuzzy multi feature pattern recognition algorithm using the monitoring signals. Quality prediction system was also developed to apply this algorithm to production line.
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Wilden, J., and Jean-Pierre Bergmann. "Mechanised Plasma-Powder-Arc-Welding (PPAW) of Aluminium Sheets." Advanced Materials Research 6-8 (May 2005): 225–34. http://dx.doi.org/10.4028/www.scientific.net/amr.6-8.225.
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The use of aluminium alloys rose in the last decade, as its specific mechanical properties allow a reduction of mass as for example in automotive. Moreover aluminium, due to its high corrosion resistance, is a very important material class in plant construction, where it is used for pipes or container till 250 °C. Aluminium can be welded with different technologies. Nowadays TIG and MIG are mainly used for example in plant construction or in mechanical engineering. Laser beam welding is a widely established technology in automotive. The advantage is the high energy concentration, which leads to a high welding speed and a narrow heat affected zone. Plasma welding is applied when joining aluminium with alternating current, as an easy removal of the oxide layer in the surface of the weld pool is possible. Plasma-Powder-Arc-Welding (PPAW) method has been developed from Plasma Transferred Arc (PTA) weld surfacing and Plasma Arc Welding (PAW) methods by combining a small PAW torch (PAW is traditionally performed with wire as filler material) with powder filler material feeding as used in PTA-equipment. The coupling leads to a better mechanisation of the welding process as the consumable is fed directly through the welding torch. In this paper investigations on aluminium sheets (£ 2 mm) AA5xxx and AA6xxx using different powder materials are reported. The influence of the processing parameters and conditions on the process reliability, when welding with industrial robots butt and corner welds is investigated. Conventional PPAW of aluminium is performed with AlSi12 filler material. A post processing of the joint, as for example anodising in order to improve corrosion resistance, leads to a very different optical aspect, as the colouration of the weld seam after anodising differs from the base material. Thanks to a correct choice of filler material it is possible to reduce the colour differences between base materials/heat affected zone and bead, so that the weldment can be set for high quality optical applications, too.
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Pérez Medina, Gladys Yerania, Elias Gabriel Carrum Siller, Argelia Fabiola Miranda Pérez, and Rocio Saldaña Garces. "MECHANICAL PROPERTIES AND DEPTH PENETRATION OPTIMIZATION USING NSGA-III IN HYBRID LASER ARC WELDING." MRS Advances 4, no. 55-56 (2019): 3053–60. http://dx.doi.org/10.1557/adv.2019.364.
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ABSTRACTHybrid welding is a process used in aeronautical materials to obtain benefits such as complete penetration, narrow heat affected zones, reduce filler material used, among others, mainly due the ability of the process to control filler-metal additions and heat input in materials such as steels, titanium and aluminum alloys. Recently a new industrial revolution is taken place called manufacturing 4.0, the aeronautical and automotive industry have a great interest in all the pillars which making it up, one of the principal pillars is the big data analysis such as welding parameters applied in advances welding processes. The present work describes a welding optimization applying non-dominated sorting genetic algorithm-III (NSGA-III) to find and predict depth penetration (DP) and mechanical properties, specifically ultimate tensile strength (UTS) in ASTM 1520 steel welded by a hybrid laser arc welding with the objective to improve the weld quality. A diverse experiment were used in order to obtain a suitable model, considering welding speed (WS), wire feed rate (WF), voltage (V), current (A) and laser power (P). The experimental results demonstrated that the pareto front values obtained by NSGA-III improve the DP and UTS. Microstructural phases and mechanical properties were discuss to complement the values obtained and chosen.
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Kannengiesser, Thomas, and Arne Kromm. "Formation of welding residual stresses in low transformation temperature (LTT) materials." Soldagem & Inspeção 14, no. 1 (March 2009): 74–81. http://dx.doi.org/10.1590/s0104-92242009000100009.
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For the safety and cost efficiency of welded high-strength steel structures, precise knowledge of the level and distribution of welding- and cooling-specific stresses and residual stresses is essential, since they exert a decisive influence on strength, crack resistance, and finally on the bearable service load. This paper presents innovative filler materials, of which the phase transformation temperature was deliberately adjusted via the chemical composition. The transformation behaviour of these martensitic Low Transformation Temperature (LTT-) filler materials shows direct effects on the local residual stresses in the weld and the HAZ. These effects can purposefully be exploited to counteract the thermally induced shrinkage of the material and to produce significant compressive residual stresses in the weld. Comparative welding experiments were carried out on 690 MPa high-strength base materials using various LTT-filler materials. High energy synchrotron radiation was used for residual stress measurement. Particularly the use of high energy synchrotron radiation makes it possible to detect the residual stress condition fast without destruction of material. Thereby, residual stress depth gradients can be determined simultaneously without removing material. In steel, gradients of up to 150 µm can be resolved in such a way. Furthermore, the application of high energy radiation permits determination of residual stresses of any available residual austenite contents. Results show significant dependence of transformation temperatures on the resulting residual stress level and distribution.
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Huang, An Guo, Shu Hui Hu, Zhi Yuan Li, and Yong Yang Wang. "Study on Elements Distribution of Al-Base Alloy’s Weld by Laser Welding with Filler Material." Applied Mechanics and Materials 121-126 (October 2011): 411–17. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.411.
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To figure out the elements distribution in the seams, laser welding was carried out on the Al plates which coating with Si powder and Cu powder respectively, then electronic probe was used to analyze the microstructure in the section of the seams. Results indicated that alloying elements distribution in the weld is heterogeneous under the metal liquid movement in welding pool and the elemental diffusion co-functioning. There are two high concentration regions on both sides of the weld centerline, the content at the center is low, slightly higher and more homogeneous at the bottom. The distribution of the alloy composition in the weld is related to the specific gravity of the alloying elements. Though the specific gravity of Si and aluminum matrix is similar, it can flow with the liquid metal in the pool, so the concentration changes of Si in the weld are larger. Elemental fluctuation keeps steady in the weld joint.
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Odanovic, Zoran, Miodrag Arsić, Vencislav Grabulov, and Mile Djurdjević. "Investigation of the Repair Welding Technology Using Ni Base Electrode." Advanced Materials Research 814 (September 2013): 25–32. http://dx.doi.org/10.4028/www.scientific.net/amr.814.25.
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Metal materials are subjected to innumerable time-dependent degradation mechanisms when operate in power, petrochemical and refinery plant. These materials are subjected to multiaxial stresses, creep, fatigue, corrosion and abrasion. As a result of service especially at high temperatures and high pressures, can lead to forming cracks, damages or failures. In situation of breakdown in such systems there is a need for weld repair on plant components and repair work can be expensive and time-consuming. Most weld repairs of low alloy steels require high-temperature post weld heat treatment (PWHT); but in certain repairs, however, this is not always possible. Expenses of the repair work could be reduced if the weld repairing is performed on site. Application of the nickel based filler metal can be alternative to performing PWHT. These repair welding procedures with Ni based filler metal could be categorized as cold repair welding. Purpose of presented investigation was to compare a repair welding technology with filler austenite material based on Ni and without application of the PWHT, with a classical repair welding procedure with preheating and PWHT and using a filler metal with chemical composition similar to parent metal. Properties comparison of the welded joints obtained by these two repair welding technologies was performed for the Cr-Mo steel (13CrMo4-5) by the metal arc welding procedure with covered electrode (MMA - 111). Weldability analysis by the analytical equations and technological tests for determination of the sensitivity to crack forming for cold and hot cracks by the CTS and Y tests, were performed for both repair welding technologies. Tensile tests, absorbed energies tests, banding tests and hardness measurements were performed on trial joins. Light optical microscopy (LOM) was applied for microstructure analysis. The fracture toughness for both technologies, were estimated by the calculated stress intensity factor KIc and dynamic stress intensity factor KId for weld metal and heat affected zone. All of the obtained results were analyzed and discussed. It was concluded that repair welding technology with Ni base filler material without PWHT, enables welded joints without the appearance of cracks, with a good mechanical properties, slightly higher hardness in the HAZ, but with lower expenses compared to standard repair welding technology. In applying this technology in emergency welding repairing on-site, on the equipment and industrial facilities with high security requirements, inspection using non destructive technique has to be frequently applied compared to standard procedures.
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Soltysiak, Robert. "Tests of Fracture Toughness of Laser-Welded Joints Made of Duplex 2205 Steel." Solid State Phenomena 250 (April 2016): 191–96. http://dx.doi.org/10.4028/www.scientific.net/ssp.250.191.
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The process of welding introduces geometric notches to the area of joined material in the form of a face and root of a weld as well as structural heterogeneity in the form of changed properties (as compared with the parent material) in the heat affected zone and the weld zone. The parent material, as compared with the zones formed by welding, may differ in fracture toughness. In this paper the results of tests of fracture toughness of DUPLEX 2205 steel laser-welded joints are presented. Butt-welded joints were made by use of an Nd-YAG disc laser with no filler. The fatigue crack was initiated in the parent material and in the area including both the heat affected zone as well as the weld zone. The tests showed higher fracture toughness of the welded joint area as compared with the parent material.
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Sołtysiak, Robert. "Effect of Laser Welding Parameters of DUPLEX 2205 Steel Welds on Fatigue Life." Solid State Phenomena 223 (November 2014): 11–18. http://dx.doi.org/10.4028/www.scientific.net/ssp.223.11.
Full textAbstract:
This paper presents the results of the fatigue tests carried out on laser welded joints of DUPLEX 2205 steel (X2CrNiMoN22-5-3 according to PN-EN 10027-1:2007). The butt-welded joints were made using an Nd-YAG disk laser with no filler for two different welding parameters. The parameters were selected based on previous tests (according to PN-EN ISO 15614-11: 2005) conducted for joints made with more than ten welding parameters.The tests carried out provided a basis for the determination of optimum parameters for laser welding of DUPLEX 2205 steel in terms of fatigue life. Additionally, the fatigue test results were related to the fatigue life of samples taken from the parent material.
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Fu, Jia, Jurriaan van Slingerland, Hans Brouwer, Vitaliy Bliznuk, Ian Richardson, and Marcel Hermans. "Applicability Study of Pulsed Laser Beam Welding on Ferritic–Martensitic ODS Eurofer Steel." Metals 10, no. 6 (June 2, 2020): 736. http://dx.doi.org/10.3390/met10060736.
Full textAbstract:
Pulsed laser beam welding was used successfully to join the oxide dispersion-strengthened (ODS) Eurofer steel. The joining was conducted with a laser power of 2500 W and a pulsed duration of 4 ms. With the filler material being used, a minor material loss and microvoids were observed in the joint. The microstructure of the fusion zone consists of dual phase elongated structures. The heat-affected zone has a width of around 0.06 mm with finer grains. The transmission electron microscopy observation reveals that nanoprecipitates are finely distributed in the fusion zone. The tensile strength, yield strength and elongation of the joint are slightly inferior to the base material. The fractography results reveal a typical ductile fracture. The experimental results indicate a reasonable joint from the perspective of both the microstructure and mechanical behaviour.