Journal articles: 'Co-Mo-Al Alloys'

1

Davidov, D. I., Igor Ezhov, Nikolay A. Popov, and Nataliya Kazantseva. "Mechanical Properties of Co-Al-Mo-Nb Intermetallic Alloys." Key Engineering Materials 910 (February 15, 2022): 1121–26. http://dx.doi.org/10.4028/p-3102k8.

Full text

Abstract:

The results of the experimental study of the mechanical properties and structure of the Co-9.5Al-2.9Mo-4Nb, Co-9.1Al-5.2Mo-4.7Nb, and Co-8.9Al-6.5Mo-9.3Nb alloys were presented. The Young’s moduli in the studied alloy samples were found to be smaller than those of Ni3Al-based and Co3(Al,W)-based alloys. The eutectic structure was observed in all studied alloys. Cuboids of the Co3(Al,Nb,Mo) intermetallic compound with L12 crystal structure were found by TEM study.

APA, Harvard, Vancouver, ISO, and other styles

2

Zhang, Qing Quan, Ming Yang Li, Ran Wei, Hui Yun Wu, and Zhen Rui Li. "Research on Effect of Alloy Elements on Equilibrium and Properties of Ni-Cr-Co Type Nickel-Based Superalloy." Materials Science Forum 849 (March 2016): 513–19. http://dx.doi.org/10.4028/www.scientific.net/msf.849.513.

Full text

Abstract:

Ni-Cr-Co type Nickel-based super alloy Inconel 740H was studied. The effect of Nb, Al and Ti on the equilibrium of this alloy was analyzed by JMatPro software. The amount of Ti and Nb should be controlled by 1.50wt.%, and meanwhile, Al should be 1.0-2.0wt.%. If Mo and W were added the amount of Mo should be in the range of 1.0-2.0wt. %, and W should be about 1.0wt.%. Based on these results, three types of new alloys were designed, which contain Ni-Cr-Co-Mo type (1#), Ni-Cr-Co-W type (2#) and Ni-Cr-Co-Mo-W type (3#). Compared with the Ni-Cr-Co type Inconel 740H alloy, the room temperature strength, high temperature strength and high temperature durable performance of the three new alloys improved, which can provide the evidence and reference to optimize the chemical composition of Inconel 740H alloy, i.e., adding 1.50wt.% Mo and 1.0wt.% W individually or together.

APA, Harvard, Vancouver, ISO, and other styles

3

Davydov, Denis, Nataliya Kazantseva, Nikolai Popov, Nina Vinogradova, and Igor Ezhov. "Phase Transitions in the Co–Al–Nb–Mo System." Metals 11, no. 12 (November 23, 2021): 1887. http://dx.doi.org/10.3390/met11121887.

Full text

Abstract:

Phase transitions in the Co-rich part of the Co–Al–Nb–Mo phase diagram are studied by energy dispersive spectroscopy (EDS), X-ray analysis, transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) measurements. The obtained results were compared with the results for alloys of the binary Co–Al and ternary Co–Al–Nb, and Co–Al–Mo systems. Formation of the intermetallic phase with the L12 structure was found in a range of alloys with 10 at.% Al, 2–9 at.% Nb, and 3–7 at.% Mo. Intermetallic compound Co2Nb, Laves phase with the different chemical composition and crystal structure (C14 and C36) was detected in the Co–Al–Nb and Co–Al–Nb–Mo samples after vacuum solution treating at 1250 °C for 30 h.

APA, Harvard, Vancouver, ISO, and other styles

4

Fan, Fei, Hao Sun, Di Zhao, and Jiang Bo Sha. "Effect of Mo on the High Temperature Oxidation Behavior of Co-Al-W Based Alloys." Materials Science Forum 747-748 (February 2013): 754–59. http://dx.doi.org/10.4028/www.scientific.net/msf.747-748.754.

Full text

Abstract:

2 at.% and 4 at.% Mo were added to Co-9Al-9W-2Ta-0.02B alloy to replace W (hereafter referred to as the alloys of 2Mo and 4Mo, respectively; Mo-free alloy was referred to as the 0Mo alloy). The effects of Mo additions on the high temperature oxidation behavior of the alloys at 800 °C in air have been studied. The results indicated that, after oxidation in air at 800 °C for 100 h, the oxide film of the 0Mo alloy remained intact, but the cracking and spallation of the oxide film took place in the alloys of 2Mo and 4Mo. Oxidation kinetic curves revealed weight gain per unit area of the 0Mo alloy was 36.86 mg·cm-2, which was lower than that of the alloys of 2Mo (65.16 mg·cm-2) and 4Mo (48.54mg·cm-2). These suggested that the 0Mo alloy displayed superior oxidation resistance compared to the alloys of 2Mo and 4Mo caused by the formation of volatile MoO3 oxide, and sharp compressive stress formed in the outer layer during the oxidation. The oxide layer was composed of three layers of the Co3O4 + CoO outer layer, middle complex oxide layer containing Co, Al and W (Mo), inner Al2O3 layer and γ/Co3W zone adhere to the γ/γ' substrate.

APA, Harvard, Vancouver, ISO, and other styles

5

Nohira, Naoki, Keiko Widyanisa, Wan-Ting Chiu, Akira Umise, Masaki Tahara, and Hideki Hosoda. "Effects of 3d Transition Metal Substitutions on the Phase Stability and Mechanical Properties of Ti–5.5Al–11.8[Mo]eq Alloys." Materials 16, no. 13 (June 22, 2023): 4526. http://dx.doi.org/10.3390/ma16134526.

Full text

Abstract:

The phase stability, mechanical properties, and functional properties of Ti–5.5Al–11.8[Mo]eq alloys are focused on in this study by substituting 3d transition metal elements (V, Cr, Co, and Ni) for Mo as β-stabilizers to achieve similar β phase stability and room temperature (RT) superelasticity. The ternary alloy systems with the equivalent chemical compositions of Ti–5.5Al–17.7V, Ti–5.5Al–9.5Cr, Ti–5.5Al–7.0Co, and Ti–5.5Al–9.5Ni (mass%) alloys were selected as the target materials based on the Mo equivalent formula, which has been applied for the Ti–5.5Al–11.8Mo alloy in the literature. The fundamental mechanical properties and functionalities of the selected alloys were examined. The β phase was stabilized at RT in all alloys except for the Ti–Al–V alloy. Among all alloys, the Ti–Al–Ni alloy exhibited superelasticity in the cyclic loading–unloading tensile tests at RT. As a result, similar to the Ti–5.5Al–11.8Mo mother alloy, by utilizing the Mo equivalent formula to substitute 3d transition metal elements for Mo, a RT superelasticity was successfully imposed.

APA, Harvard, Vancouver, ISO, and other styles

6

Inoue, Akihisa, Bao Long Shen, and Akira Takeuchi. "Syntheses and Applications of Fe-, Co-, Ni- and Cu-Based Bulk Glassy Alloys." Materials Science Forum 539-543 (March 2007): 92–99. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.92.

Full text

Abstract:

This paper reviews our recent results of the formation, fundamental properties, workability and applications of late transition metal (LTM) base bulk glassy alloys (BGAs) developed since 1995. The BGAs were obtained in Fe-(Al,Ga)-(P,C,B,Si), Fe-(Cr,Mo)-(C,B), Fe-(Zr,Hf,Nb,Ta)-B, Fe-Ln-B(Ln=lanthanide metal), Fe-B-Si-Nb and Fe-Nd-Al for Fe-based alloys, Co-(Ta,Mo)-B and Co-B-Si-Nb for Co-based alloys, Ni-Nb-(Ti,Zr)-(Co,Ni) for Ni-based alloys, and Cu-Ti-(Zr,Hf), Cu-Al-(Zr,Hf), Cu-Ti-(Zr,Hf)-(Ni,Co) and Cu-Al-(Zr,Hf)-(Ag,Pd) for Cu-based alloys. These BGAs exhibit useful properties of high mechanical strength, large elastic elongation and high corrosion resistance. In addition, Fe- and Co-based glassy alloys have good soft magnetic properties which cannot be obtained for amorphous and crystalline type magnetic alloys. The Feand Ni-based BGAs have already been used in some application fields. These LTM base BGAs are promising as new metallic engineering materials.

APA, Harvard, Vancouver, ISO, and other styles

7

Peng, Yuhan, Ge Zhou, Jinke Han, Jianlin Li, Haoyu Zhang, Siqian Zhang, Li Lin, Lijia Chen, and Xue Cao. "Effect of Heat Treatment on the Corrosion Resistance of AlFeCoNiMo0.2 High-Entropy Alloy in NaCl and H2SO4 Solutions." Metals 13, no. 5 (April 26, 2023): 849. http://dx.doi.org/10.3390/met13050849.

Full text

Abstract:

The effects of casting and different heat treatment processes on the corrosion resistance of AlFeCoNiMo0.2 high-entropy alloy in 3.5% NaCl (mass fraction) and 0.5 mol/L H2SO4 solutions were investigated using dynamic potential polarization curves, SEM, XRD, XPS, and other test methods. The results show that in the Cl− environment, the cast alloy has the lowest corrosion current density and higher corrosion resistance compared to the annealed alloy. The elements Al and Mo are severely segregated in the crystal and in the grain boundaries, where galvanic corrosion occurs, and the Al-rich phase produces pitting corrosion in the crystal. The main components of its passive film are oxides of Al, Fe, Co, and Mo, and oxides and hydroxides of Ni. In the SO42− environment, the best corrosion resistance is achieved in the 900 °C annealed state of the alloy. Electrochemical test results show that the alloys all undergo secondary passivation, producing two successive product films to protect the metal matrix. Preferential corrosion areas are concentrated in the molybdenum-rich grain boundaries and nearby dendritic regions, reducing the corrosion resistance of the alloy. The main components of the passive film are oxides of Al and Mo; oxides of Fe, Co, Ni; and hydroxides. The Mo element in the passive film prevents the activated dissolution of Fe and produces the protective component MoO3, which inhibits the dissolution of the alloy and improves the stability of the passive film. The presence of Mo elements increases the selective dissolution of Fe, and the aggregation of Mo elements at grain boundaries after annealing weakens the corrosion resistance of the alloy and leads to the dissolution of the passive film. The main components of the passive film are oxides of Al and Mo; oxides of Fe, Co, Ni; and hydroxides.

APA, Harvard, Vancouver, ISO, and other styles

8

Sanin, Vitaliy V., Yury Yu Kaplansky, Maksym I. Aheiev, Evgeny A. Levashov, Mikhail I. Petrzhik, Marina Ya Bychkova, Andrey V. Samokhin, Andrey A. Fadeev, and Vladimir N. Sanin. "Structure and Properties of Heat-Resistant Alloys NiAl–Cr–Co–X (X = La, Mo, Zr, Ta, Re) and Fabrication of Powders for Additive Manufacturing." Materials 14, no. 12 (June 8, 2021): 3144. http://dx.doi.org/10.3390/ma14123144.

Full text

Abstract:

The NiAl–Cr–Co–X alloys were produced by centrifugal self-propagating high-temperature synthesis (SHS) casting. The effects of dopants X = La, Mo, Zr, Ta, and Re on combustion, as well as the phase composition, structure, and properties of the resulting cast alloys, have been studied. The greatest improvement in overall properties was achieved when the alloys were co-doped with 15% Mo and 1.5% Re. By forming a ductile matrix, molybdenum enhanced strength characteristics up to the values σucs = 1604 ± 80 MPa, σys = 1520 ± 80 MPa, and εpd = 0.79%, while annealing at T = 1250 ℃ and t = 180 min improved strength characteristics to the following level: σucs = 1800 ± 80 MPa, σys = 1670 ± 80 MPa, and εpd = 1.58%. Rhenium modified the structure of the alloy and further improved its properties. The mechanical properties of the NiAl, ZrNi5, Ni0.92Ta0.08, (Al,Ta)Ni3, and Al(Re,Ni)3 phases were determined by nanoindentation. The three-level hierarchical structure of the NiAl–Cr–Co+15%Mo alloy was identified. The optimal plasma treatment regime was identified, and narrow-fraction powders (fraction 8–27 µm) characterized by 95% degree of spheroidization and the content of nanosized fraction <5% were obtained.

APA, Harvard, Vancouver, ISO, and other styles

9

Yao, Qiang, Tong Lu, Qiong Wang, Yan Wang, and Yu Hong Zhu. "First-Principles Investigation of Phase Stability, Elastic and Thermodynamic Properties in L1₂ Co₃(Al,Mo,Ta) Phase." Materials Science Forum 898 (June 2017): 438–45. http://dx.doi.org/10.4028/www.scientific.net/msf.898.438.

Full text

Abstract:

First-principles calculations have been performed to investigate the phase stability, elastic, and thermodynamic properties of Co3(Al,Mo,Ta) with the L12 structure. Calculated elastic constants showed that Co3(Al,Mo,Ta) is mechanically stable and possesses intrinsic ductility. Young’s and shear moduli of polycrystalline Co3(Al,Mo,Ta) were calculated using the Voigt-Reuss-Hill approach. It was found that the shear and Young’s moduli of Co3(Al,Mo,Ta) were smaller than those of Co3(Al,W). States density indicated the existence of covalent-like bonding in Co3(Al,Mo,Ta). Temperature-dependent thermodynamic properties of Co3(Al,Mo,Ta) could be described satisfactorily using the Debye-Grüneisen approach, including entropy, enthalpy, heat capacity and linear thermal expansion coefficient, showing their significant temperature dependences. Furthermore the obtained data could be employed in the modeling of thermodynamic and mechanical properties of Co-based alloys to enable the design of high temperature alloys.

APA, Harvard, Vancouver, ISO, and other styles

10

Kitajima, Yuri, Shigenari Hayashi, Shigeharu Ukai, and Toshio Narita. "The Effect of Additional Elements on Oxide Scale Evolution of Fe-20at.%Cr-10at.%Al Alloy at 900 °C in Air." Materials Science Forum 595-598 (September 2008): 1013–21. http://dx.doi.org/10.4028/www.scientific.net/msf.595-598.1013.

Full text

Abstract:

The oxidation behavior of Fe-20at.%Cr-10at.%Al alloys with a small amount of an additional element such as W, Cu, Mn, Nb, Mo, Re, Co or Ti was investigated at 900 °C for up to 625hr. The fourth element addition to the FeCrAl alloy could be classified into two groups; elements (Mn, Nb, Ti) that are contained in the Al2O3 scale, and elements (W, Mo, Re, Co) which are not present in the scale. In the latter case, the elements (W, Cu) caused scale spallation. The rumpling of alloys with Mn, Nb or Ti was smaller than that of the other alloys. The surface of the alloy with Ti was the smooth. Pt marker experiments suggested that the Al2O3 scale formed on the alloy with Ti grew by inward diffusion of O, whilst the Al2O3 scale formed on the FeCrAl alloy grew by both outward diffusion of Al and inward diffusion of O. This different growth behavior due to the elements incorporated in the Al2O3 scale could have an effect on the surface rumpling behavior.

APA, Harvard, Vancouver, ISO, and other styles

11

Park, Si-Jun, Seong-Moon Seo, Young-Soo Yoo, Hi-Won Jeong, and HeeJin Jang. "Statistical Study of the Effects of the Composition on the Oxidation Resistance of Ni-Based Superalloys." Journal of Nanomaterials 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/929546.

Full text

Abstract:

The effects of alloying elements (Co, Cr, Mo, W, Al, Ti, and Ta) on the oxidation resistance of Ni-based superalloys are studied using the Response Surface Methodology (RSM). The statistical analysis showed that Al and Ta generally improve the oxidation resistance of the alloy, whereas Ti and Mo degrade the oxidation resistance. Co, Cr, and W did not alter oxidation rate significantly when examined by the mass gain averaged for all model alloys. However, it is remarkable that the degree of the effects of alloying elements varied with the concentration of other elements. Further, the effect of each element was sometimes found to be reversed for alloy groups specified by the concentration of another element.

APA, Harvard, Vancouver, ISO, and other styles

12

Migas, Damian, Grzegorz Moskal, and Tomasz Maciąg. "Thermal analysis of W-free Co–(Ni)–Al–Mo–Nb superalloys." Journal of Thermal Analysis and Calorimetry 142, no. 1 (February 24, 2020): 149–56. http://dx.doi.org/10.1007/s10973-020-09375-7.

Full text

Abstract:

Abstract In this investigation, the thermal analysis of W-free cobalt-based superalloys based on Co–Al–Mo–Nb and Co–Ni–Al–Mo–Nb systems was performed. The analysis was performed at different stages of heat treatment process. The differential thermal analysis (DTA) was utilized for the determination of characteristic temperatures related to microstructural changes. First of all, the DTA analysis was carried out for discussing as-cast alloys in the temperature range of 40–1500 °C. The results showed thermal effects connected with melting and important order–disorder transition. The temperature range of 1200–1250 °C was chosen for performance of a first heat treatment operation for the investigated alloys. Specimens were annealed at selected temperature for 5 h. The microstructure of alloys after solution heat treatment was analyzed as well. Afterward, the solutionized specimens were subjected to the further thermal analysis in order to select the aging temperature according to the order–disorder transformation related to formation of γ′ phase with overall formula Co3(Al,X). Five aging variants were performed in the temperature range of 800–1000 with a step of 50 °C. After each stage of heat treatment, SEM/EDS analysis and hardness measurements were performed.

APA, Harvard, Vancouver, ISO, and other styles

13

Gubin, Dmitry, and Anton Kisel'. "Calculation of temperatures during finishing milling of a nickel based alloys." Metal Working and Material Science 24, no. 1 (March 15, 2022): 23–32. http://dx.doi.org/10.17212/1994-6309-2022-24.1-23-32.

Full text

Abstract:

Introduction. One of the most important tasks in cutting metals and alloys is the control of the temperature factor, since temperature is one of the limitations in determining cutting conditions. This approach makes it possible to determine rational (in some cases, optimal) milling modes. Experimental methods for determining the temperature are labor-consuming, costly and not always available. The labor-consuming nature lies in the need for constant adjustment of experimental equipment due to changing cutting conditions, electrical insulation of the tool and workpiece, the appearance of parasitic electrical micro-voltage (if we are talking about temperature measurement methods with thermocouples), constant calibration of instruments and selection of thermal radiation coefficients (if we are talking about non-contact measurement methods). In this regard, there is a need for a theoretical determination of temperatures during milling with minimal use of experimental data. The purpose of the work: to develop a method for theoretical calculation of temperature during milling (cutting) of nickel-based heat-resistant materials on the example of 56% Ni -Cr-W Mo-Co-Al alloy (56% Ni, 0.1% C, 10% Cr, 6.5% W, 6% Al, 6.5% Mo, 0.6% Si, 13 % Co, 1% Fe). Research methodology. To determine theoretically the cutting temperatures, a mathematical model is formed that takes into account the mechanical and thermophysical properties of the material being processed and its change depending on the temperature variations during milling, the geometry of the cutting tool and the features of the schematization of the milling process. The experimental part of the study is carried out on a console milling machine KFPE-250 with a CNC system Mayak-610. The 56% Ni -Cr-W Mo-Co-Al material is processed with a Seco JS513050D2C.0Z3-NXT cutter with different speeds and feeds. The temperature is measured using a Fluke Ti400 thermal imager. Results and discussion. A theoretical model for calculating the temperature (for the group of 77% Ni - Cr - Ti - Al - B, 66% Ni - Cr - Mo - W - Ti - Al, 73% Ni-Cr-Mo-Nb-Ti-Al and 56% Ni -Cr-W Mo-Co-Al alloys) during milling of heat-resistant nickel-based alloys is developed, which makes it possible to predict the temperature value at the face and flank of the tool when changing cutting conditions (speed, feed, depth, cutting tool geometry), as well as the cutting temperature. An analysis of the experimental and theoretically predicted values of the cutting temperature showed a satisfactory agreement between the corresponding values.

APA, Harvard, Vancouver, ISO, and other styles

14

Ghiban, Nicolae, Brandusa Ghiban, Nicolae Şerban, and Alexandru Ghiban. "Heat Treatments Influence on Corrosion Behaviour of Some Metallic Biomaterials Potentially Used in Metal-Ceramic Prosthesis." Key Engineering Materials 587 (November 2013): 293–96. http://dx.doi.org/10.4028/www.scientific.net/kem.587.293.

Full text

Abstract:

The present paper put in evidence the influence of applying different heat treatments on some metallic materials such as cobalt and titanium alloys, usualy used for medical applications. The alloys were cobalt base alloy type CoCrMo (22%Cr, 6%Mo, rest Co), in nontreated state, quenching at 1100°C /1h/aer, quenching at 1100°C /1h/air+ sensiblizing at 550°/4h/ air, 600°/4h/air and/or 650°C/4h/air and titanium base alloys - alloy TiMo0.3Ni0,7 (0.23%Mo, 0.72%Ni, Ti rest), alloy TiAl5Fe2V2Mo1,5(1.52%Mo, 5.15%Al, 2.56%Fe, 2.35%V, Ti rest), each of them in non treated state, annealing at 1050°C/1h/air and annealing at 850°C/1h/air. Corrosion tests were made at potentiostat-galvanostat AUTOLAB, in Ringer solution (for both alloys) and NaCl infusion solution (only for cobalt base alloy) by drawing the polarization curves. Our conclusion is that by applying correct and proper heat treatments to both at cobalt alloys and in titanium alloys there is an improving of the corrosion resistance.

APA, Harvard, Vancouver, ISO, and other styles

15

Xue, Fei, Zhi Qiang Li, and Qiang Feng. "Mo Effect on the Microstructure in Co-Al-W-Based Superalloys." Materials Science Forum 654-656 (June 2010): 420–23. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.420.

Full text

Abstract:

The as-cast and heat-treated microstructure has been investigated in Co-Al-W-based superalloys with additions of 2 and 4 at.% Mo. The results revealed that Mo promoted the formation of (μ+γ) eutectic structure in the as-cast alloys and μ-phase precipitation after solution treatment. In addition, after aging treatment at 900oC, an extensive network of DO19 precipitates was observed, besides the γ+γ′ primary phases and the μ phase inherited from the as-cast and solution-treated conditions. Meanwhile, a solid-state transformation from the μ phase to the DO19 phase occurred; and long-term aging enhanced this transformation. In addition, high levels of Mo promoted the DO19-phase precipitation.

APA, Harvard, Vancouver, ISO, and other styles

16

Dvoretskov, R. M., А. V. Slavin, F. N. Karachevtsev, and Т. N. Zagvozdkina. "COMPARISONS OF THE NICKEL ALLOYS VZH172 AND VZHL21 REFERENCE MATERIALS KITS USING THE AES ICP METHOD." Proceedings of VIAM, no. 11 (2021): 120–32. http://dx.doi.org/10.18577/2307-6046-2021-0-11-120-132.

Full text

Abstract:

The procedure for comparing the kits of reference materials of nickel alloys VZh172 and VZhL21 is considered. Using the method of atomic emission spectrometry with inductively coupled plasma for analytical lines of elements Al, Co, Cr, Mo, Ti, W, Zr, Fe, Mn, calibration characteristics were constructed using by two kits of reference materials VZh172 and VZhL21. According to statistical criteria an assessment is made of the possibility of joint use of the kits when constructing general calibration characteristics using the method of atomic emission spectrometry with inductively coupled plasma for the simultaneous determination of elements Al, Co, Cr, Mo, Nb, Ta, Ti, W, Zr, Fe, Mn in nickel alloys.

APA, Harvard, Vancouver, ISO, and other styles

17

Tian, Jinzhong, Yuhong Zhao, Hua Hou, and Bing Wang. "The Effect of Alloying Elements on the Structural Stability, Mechanical Properties, and Debye Temperature of Al3Li: A First-Principles Study." Materials 11, no. 8 (August 18, 2018): 1471. http://dx.doi.org/10.3390/ma11081471.

Full text

Abstract:

The structural stability, mechanical properties, and Debye temperature of alloying elements X (X = Sc, Ti, Co, Cu, Zn, Zr, Nb, and Mo) doped Al3Li were systematically investigated by first-principles methods. A negative enthalpy of formation ΔHf is predicted for all Al3Li doped species which has consequences for its structural stability. The Sc, Ti, Zr, Nb, and Mo are preferentially occupying the Li sites in Al3Li while the Co, Cu, and Zn prefer to occupy the Al sites. The Al–Li–X systems are mechanically stable at 0 K as elastic constants Cij has satisfied the stability criteria. The values of bulk modulus B for Al–Li–X (X = Sc, Ti, Co, Cu, Zr, Nb, and Mo) alloys (excluding Al–Li–Zn) increase with the increase of doping concentration and are larger than that for pure Al3Li. The Al6LiSc has the highest shear modulus G and Young’s modulus E which indicates that it has stronger shear deformation resistance and stiffness. The predicted universal anisotropy index AU for pure and doped Al3Li is higher than 0, implying the anisotropy of Al–Li–X alloy. The Debye temperature ΘD of Al12Li3Ti is highest among the Al–Li–X system which predicts the existence of strong covalent bonds and thermal conductivity compared to that of other systems.

APA, Harvard, Vancouver, ISO, and other styles

18

Chen, Shuyang, James K. H. Tsoi, Peter C. S. Tsang, Yeong-Joon Park, Ho-Jun Song, and Jukka P. Matinlinna. "Candida albicans aspects of binary titanium alloys for biomedical applications." Regenerative Biomaterials 7, no. 2 (January 25, 2020): 213–20. http://dx.doi.org/10.1093/rb/rbz052.

Full text

Abstract:

Abstract Titanium and its alloys are widely used in biomedical devices, e.g. implants, due to its biocompatibility and osseointegration ability. In fact, fungal (Candida spp.) infection has been identified as one of the key reasons causing the failure of the device that is inevitable and impactful to the society. Thus, this study evaluated the surface morphology, surface chemical composition and Candida albicans adhesion on specimens of 16 binary Ti-alloys (∼5 wt% of any one of the alloy elements: Ag, Al, Au, Co, Cr, Cu, Fe, In, Mn, Mo, Nb, Pd, Pt, Sn, V and Zr) compared with cp-Ti, targeting to seek for the binary Ti-alloys which has the lowest C. albicans infection. Candida albicans cultures were grown on the specimens for 48 h, and colony forming units (CFUs) and real-time polymerase chain reaction (RT-PCR) were used to evaluate the biofilm formation ability. Scanning electron microscopy and confocal laser scanning microscopy confirmed the formation of C. albicans biofilm on all specimens’ surfaces, such that CFU results showed Ti-Mo, Ti-Zr, Ti-Al and Ti-V have less C. albicans formed on the surfaces than cp-Ti. RT-PCR showed Ti-Zr and Ti-Cu have significantly higher C. albicans DNA concentrations than Ti-Al and Ti-V (P < 0.05), whereas Ti-Cu has even showed a statistically higher concentration than Ti-Au, Ti-Co, Ti-In and Ti-Pt (P < 0.05). This study confirmed that Ti-Mo, Ti-Zr, Ti-Al and Ti-V have lower the occurrence of C. albicans which might be clinically advantageous for medical devices, but Ti-Cu should be used in caution.

APA, Harvard, Vancouver, ISO, and other styles

19

Yamanaka, Syuki, Ken-ichi Ikeda, and Seiji Miura. "Effect of Multi-Elements Substitution on the Mechanical Properties of Intermetallic Compound." MRS Advances 4, no. 25-26 (2019): 1497–502. http://dx.doi.org/10.1557/adv.2019.119.

Full text

Abstract:

ABSTRACTIt is well known that various elements substitute for a certain sub-lattice of intermetallic compounds. There have been various experimental investigations of the effects of substituted elements on mechanical properties, however, there are few reports describing the effects of multi-element substitution. In the present study, L12-type compounds A3B (Ni3Al and Co3(Al,W)) were selected as model compounds because their substitution behavior is well known. It was reported that various elements such as Ni, Co, Cu, Pd and Pt occupy the A-site, whereas Al, Si, Ga, Ge, Ti, V, Nb, Ta, Mo, and W occupy the B-site. These elements are expected to introduce local lattice distortion, which may affect the motion of dislocations over a wide range of temperatures. Several alloys composed of five or more elements including Ni, Co, Al, Mo, and W, were prepared using an Ar-arc melting machine and heat-treated. Several alloys were found to include an (Ni, Co)3(Al, Mo, W, …)-L12 compound as a constituent phase. The nano-hardness of these L12 phases was higher than that of the high-strength Co3(Al,W)-L12 compound, confirming that multi-element substitution is an effective way to improve the mechanical properties of an intermetallic compound without decreasing the phase stability.

APA, Harvard, Vancouver, ISO, and other styles

20

Al-Zoubi, Noura. "Elastic Parameters of Paramagnetic Fe–20Cr–20Ni-Based Alloys: A First-Principles Study." Metals 9, no. 7 (July 17, 2019): 792. http://dx.doi.org/10.3390/met9070792.

Full text

Abstract:

The single-crystal and polycrystalline elastic parameters of paramagnetic Fe0.6−xCr0.2Ni0.2Mx (M = Al, Co, Cu, Mo, Nb, Ti, V, and W; 0 ≤ x ≤ 0.08) alloys in the face-centered cubic (fcc) phase were derived by first-principles electronic structure calculations using the exact muffin-tin orbitals method. The disordered local magnetic moment approach was used to model the paramagnetic phase. The theoretical elastic parameters of the present Fe–Cr–Ni-based random alloys agree with the available experimental data. In general, we found that all alloying elements have a significant effect on the elastic properties of Fe–Cr–Ni alloy, and the most significant effect was found for Co. A correlation between the tetragonal shear elastic constant C′ and the structural energy difference ΔE between fcc and bcc lattices was demonstrated. For all alloys, small changes in the Poisson’s ratio were obtained. We investigated the brittle/ductile transitions formulated by the Pugh ratio. We demonstrate that Al, Cu, Mo, Nb, Ti, V, and W dopants enhance the ductility of the Fe–Cr–Ni system, while Co reduces it. The present theoretical data can be used as a starting point for modeling the mechanical properties of austenitic stainless steels at low temperatures.

APA, Harvard, Vancouver, ISO, and other styles

21

Cai, Ze-Xing, Hiromi Goou, Yoshikazu Ito, Tomoharu Tokunaga, Masahiro Miyauchi, Hideki Abe, and Takeshi Fujita. "Nanoporous ultra-high-entropy alloys containing fourteen elements for water splitting electrocatalysis." Chemical Science 12, no. 34 (2021): 11306–15. http://dx.doi.org/10.1039/d1sc01981c.

Full text

Abstract:

Nanoporous ultra-high-entropy alloys containing 14 elements (Al, Ag, Au, Co, Cu, Fe, Ir, Mo, Ni, Pd, Pt, Rh, Ru, and Ti) were obtained by dealloying. The products showed excellent electrocatalytic performance for water splitting in acidic media.

APA, Harvard, Vancouver, ISO, and other styles

22

Nakano, Takayoshi, Keita Sasaki, Koji Hagihara, Takuya Ishimoto, Yusuke Fujii, and Ai Serizawa. "Single Crystal Growth and its Microstructure in Co-Cr-Mo Alloys for Biomedical Applications." Materials Science Forum 706-709 (January 2012): 561–65. http://dx.doi.org/10.4028/www.scientific.net/msf.706-709.561.

Full text

Abstract:

Co-Cr-Mo based alloys have been widely employed as heat resistant materials and as biomaterials for implants because of their high strength and superior wear resistance. In general, the alloys exhibit a very complicated composition-dependent microstructure containing stacking faults and related mechanical properties. Thus, the essential properties must be clarified by using not only polycrystals but also single crystals. To our knowledge, single crystals and related properties have not been reported elsewhere. Thus, Co-Cr-Mo single crystals were grown and used to analyze the microstructure and the related properties. Single crystals with a composition Co-27 mass% Cr-6 mass% Mo alloy defined by ASTM F75 were grown by two single crystal apparatuses: the optical floating zone and the Bridgman methods. The single crystals with the smooth-surface shape were successfully obtained in the Bridgman method under an Ar gas atmosphere at a crystal growth rate of 5.0 or 2.5 mm/h. A portion of the crystals contain Al as Al2O3 precipitates from the crucible. Since the Al2O3 precipitate induces martensitic phase transformation from fcc (γ) phase to hcp (ε) phase, the single crystals were separated into two parts (a) containing Al2O3 precipitate and (b) in the absence of the clear precipitate. The microstructure was significantly altered by the martensitic phase transformation from the γ to ε phase induced by stress field or heating. In addition, variant formation of ε phase has a large influence on the mechanical functions of these Co-Cr-Mo alloys. Novel findings were preliminary obtained in the single crystals.

APA, Harvard, Vancouver, ISO, and other styles

23

Davydov, D. I., N. V. Kazantseva, N. A. Popov, I. V. Narygina, and E. N. Popova. "Structure and Phase Composition of Refractory Alloys of the Co – Al – Mo – Nb System." Metal Science and Heat Treatment 62, no. 7-8 (November 2020): 475–78. http://dx.doi.org/10.1007/s11041-020-00587-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Xie, Xi Shan, Shuang Qun Zhao, Jian Xin Dong, Gaylord D. Smith, B. A. Baker, and Shalesh J. Patel. "Modification of Ni-Cr-Co-Mo-Nb-Ti-Al Superalloy for USC Power Plant Application at Temperature above 750°C." Materials Science Forum 561-565 (October 2007): 471–76. http://dx.doi.org/10.4028/www.scientific.net/msf.561-565.471.

Full text

Abstract:

A recent developed Ni-Cr-Co-Mo-Nb-Ti-Al type nickel-base superalloy, INCONEL 740, has been selected for the application of USC boilers at the temperature above 750°C. This paper focuses on the structure stability improvement of this alloy. Phase computation by Thermo-Calc has been adopted to study main influencing factors on precipitating phases of the alloy and the results show that the ratio of Al/Ti plays an important role. Four new modified alloys in adjustment of Al and Ti contents and in control of Si level were designed and melted for experimental study. The results indicate that the modified alloys exhibit more stable structure stability at 750, 800 and 850°C long time exposure. The newly developed alloy can be adopted for engineering production and application for USC power plants at temperature above 750°C.

APA, Harvard, Vancouver, ISO, and other styles

25

Bondarenko, Yu A., M. Yu Kolodyazhnyy, and V. A. V. A. "Creation of high-temperature heat-resistant alloys based on refractory matrices and natural composites." Perspektivnye Materialy 2 (2021): 5–15. http://dx.doi.org/10.30791/1028-978x-2021-2-5-16.

Full text

Abstract:

The scientific, technical and technological aspects in the field of creating new high-temperature materials for the hot tract parts of gas turbine engines (GTE) with operating temperatures exceeding those existing in the GTE are considered. Investigated more refractory metal materials to create new high-temperature alloys used in the manufacture of working and nozzle blades and other parts of promising gas turbine engines based on Co – Cr, Pt – Al, Nb – Si, Mo – Si – B systems. In Co – Cr alloys, heat resistance is mainly ensured by hardening the Co matrix, including dispersed precipitates of the carbide phase (TaC) and the boride phase Cr2B. In alloys of the Pt – Al system, due to the doping of Cr, Al, Ti, Re ... and precipitates of the coherently embedded Pt3Al phase. In eutectic alloys of the Nb-Si system, this is due to complex hardening of the Nb solid solution and Nb5Si3 silicide, as well as the natural compositional structure. In Mo – Si – B alloys, high strength is achieved by doping a-Mo solid solution and the formation of intermetallic phases Mo3Si, Mo5SiB2, carbides Mo2C, TiC. Compositions were selected, analysis of their smelting methods was carried out, including directed crystallization, which provides a natural compositional structure, mechanical properties at room and high temperatures, oxidation resistance were evaluated, structural features were investigated, information was provided on technological equipment and the possibility of obtaining parts in various ways. It is shown that, depending on the composition of the selected matrix, the working temperature of heat-resistant alloys can increase to 1300 – 1500 °C, which significantly exceeds the existing nickel heat-resistant alloys. It is concluded that the materials under study are promising for use in aircraft engine building and the aerospace industry.

APA, Harvard, Vancouver, ISO, and other styles

26

Kim, Y. Z., T. Murakami, Takayuki Narushima, Yasutaka Iguchi, and Chiaki Ouchi. "Surface Hardening Treatment in Use of CO Gas and Post-Heat Treatment in C.P. Titanium and Titanium Alloys." Solid State Phenomena 118 (December 2006): 109–14. http://dx.doi.org/10.4028/www.scientific.net/ssp.118.109.

Full text

Abstract:

Surface hardening treatment of titanium materials in use of CO gas was studied including investigation of post heat treatment under vacuum. C.P. titanium, α+β type SP-700 alloy with Ti-4.5%Al-3%V-2%Mo-2%Fe and β type alloy with Ti-15%Mo-5%Zr-3%Al were used. Surface hardening was conducted by heating these materials at 1073K for 21.6ks in Ar-5%CO gas. Subsequently, specimens subjected to surface hardening were heated at 1073k for various time periods under vacuum. While the maximum surface hardness value was the largest in C.P. titanium and the least in SP-700 alloy, hardening layer thickness was the thickest in β type alloy and the thinnest in C.P. titanium. Surface hardening in C.P. titanium was brought about by solid solution hardening due to oxygen and carbon. Enrichment of these elements in the surface layer of both titanium alloys caused continuous variations of the microstructure such as β to α+β, or their volume fractions in the surface hardening layer. Post heat treatment at 1073K increased the maximum surface hardness and hardening layer thickness with an extension of the heating time in C.P. titanium, but the surface maximum hardness decreased continuously in β type titanium alloy. Post heat treatment could remove the thin oxide layer formed by surface hardening treatment.

APA, Harvard, Vancouver, ISO, and other styles

27

Sanin, V. V., M. I. Aheiev, Yu Yu Kaplanskii, and M. I. Petrzhik. "Influence of molybdenum and rhenium alloying additives on NiAl–Cr–Co cast alloy structure and properties." Izvestiya vuzov. Poroshkovaya metallurgiya i funktsional’nye pokrytiya, no. 3 (September 17, 2021): 43–61. http://dx.doi.org/10.17073/1997-308x-2021-3-43-61.

Full text

Abstract:

A centrifugal SHS casting technology was used to obtain NiAl–Cr–Co–(X) alloys where X = 2.5÷15.0 wt.% Mo and up to 1.5 wt% Re. The study covers the effect of modifying additives on the combustion process as well as the phase composition, structure, and properties of cast alloys. Alloying up to 15 % Mo and 1.5 % Re provided the highest improvement of properties in relation to the base alloy in terms of overall performance. Molybdenum formed a plastic matrix and improved strength properties to the following values: uniaxial compressive strength σucs = 1730±30 MPa, yield strength σys = 1560±30 MPa, plastic component of deformation εpd = 0.95 %, and annealing at t = 1250 °С improved them to: σucs = 1910±80 MPa, σys = 1650±80 MPa, εpd = 2.01 %. Rhenium modified the alloy structure and improved its properties to: σucs = 1800±30 MPa, σys = 1610±30 MPa, εpd = 1.10 %, and annealing further improved them to: σucs = 2260±30 MPa, σys = 1730±30 MPa, εpd = 6.15 %. The mechanical properties of the NiAl, (Ni,Cr,Co)3Mo3C, Ni3Al, (Cr, Mo) and MoRe2 phases, as well as the hypothetical Al(Re,Ni)3 phase, were determined by the nanoindentation method. According to the Guinier–Preston structural transformation, local softening upon annealing at t > 850 °С increases the proportion of plastic deformation during compression tests due to the lost coherence of the boundaries of nanosized plate-shaped Cr-based precipitates with a supersaturated solid solution. A hierarchical three-level structure of the NiAl–Cr– Co–15%Mo alloy was established: the first level is formed by β-NiAl dendritic grains with interlayers of molybdenum-containing phases (Ni,Co,Cr)3Mo3C and (Mo0.8Cr0.2)xBy with a cell size of up to 50 μm; the second one consists of strengthening submicron Cr(Mo) particles distributed along grain boundaries; the third one is coherent nanoprecipitates of Cr(Mo) (10–40 nm) in the body of β-NiAl dendrites. The cast alloy mechanical grinding techniques were used to obtain a precursor powder with an average particle size of Dav = 33.9 μm for subsequent spheroidization.

APA, Harvard, Vancouver, ISO, and other styles

28

Im, Hye Ji, Won Seok Choi, KenHee Ryou, Jae Bok Seol, Tae Hyeok Kang, Won-Seok Ko, and Pyuck-Pa Choi. "Enhanced microstructural stability of γ/γ′-strengthened Co-Ti-Mo-based alloys through Al additions." Acta Materialia 214 (August 2021): 117011. http://dx.doi.org/10.1016/j.actamat.2021.117011.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Xie, Xi Shan, Shuang Qun Zhao, Jian Xin Dong, Gaylord D. Smith, and Shalesh J. Patel. "An Investigation of Structure Stability and Its Improvement on New Developed Ni-Cr-Co-Mo-Nb-Ti-Al Superalloy." Materials Science Forum 475-479 (January 2005): 613–18. http://dx.doi.org/10.4028/www.scientific.net/msf.475-479.613.

Full text

Abstract:

A new nickel-base superalloy Ni-25Cr-20Co-0.5Mo-2Nb-1.7Ti-0.8Al has just developed by Special Metals Corporation in the application to ultra-supercritical boilers with steam temperatures up to 700°C. The structure stability of the alloy was studied in detail in combination of SEM, TEM, XRD and micro-chemical phase analyses. Experimental results show that the most important structure instability is as follows: 1) g¢ coarsening; 2) g¢ to h transformation; 3) G phase formation. The phase computation by means of Thermo-Calc has been adopted in chemical composition modification for structure stability improvement. Two suggested new modified alloys in adjustment of the Al and Ti contents and in control of Si level were designed and melted for experimental study. These 2 modified new alloys exhibit more stable structure at 760oC long time aging. A bright perspective has been shown for the development of this new alloy in the near future.

APA, Harvard, Vancouver, ISO, and other styles

30

Prüβner, K., K. B. Alexander, B. A. Pint, P. F. Tortorelli, and I. G. Wright. "Interfacial Segregation in Oxide Scales on Nicrai-Based Alloys." Microscopy and Microanalysis 3, S2 (August 1997): 785–86. http://dx.doi.org/10.1017/s1431927600010813.

Full text

Abstract:

Previous studies addressing the segregation of reactive elements in protective oxide scales and their beneficial effect on scale adhesion have primarily concentrated on primary alumina-formers (e.g. β-NiAl + FeCrAl).In our study the oxidation behaviour of three NiCrAl alloys, which form complex scales was studied in air at 1423 K and at 1473 K, both in isothermal (100 h) and in cyclic oxidation (100 x lh). The composition (in at.-%) of these alloys is the following: General Electric alloy René N5 (64.9 Ni, 7.8 Cr, 13.9 Al, 0.1 Fe, 2.1 Ta, 0.05 Hf, 1.6 W, 1.0 Re, 0.15 Si, 7.3 Co, 0.9 Mo, 0.003 Y, 0.003 Zr, 4 ppm S, 0.25 C), Ni-7Cr-6.5Al+Y (80.1 Ni, 7.2 Cr, 12.5 Al, 0.01 Fe, 0.14 Si, 0.012 Y, 18 ppm S, 0.05 C) and Ni-10Cr-10Al+Y (71.2 Ni, 9.9 Cr, 18.8 Al, 0.01 Fe, 0.02 Si, 0.041 Y, 16 ppm S, 0.04 C).

APA, Harvard, Vancouver, ISO, and other styles

31

Yao, M. X., J. B. C. Wu, and R. Liu. "Microstructural characteristics and corrosion resistance in molten Zn–Al bath of Co–Mo–Cr–Si alloys." Materials Science and Engineering: A 407, no. 1-2 (October 2005): 299–305. http://dx.doi.org/10.1016/j.msea.2005.07.054.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Lu, Z. P., C. T. Liu, C. A. Carmichael, W. D. Porter, and S. C. Deevi. "Bulk Glass Formation in an Fe-Based Fe–Y–Zr–M (M = Cr, Co, Al)–Mo–B System." Journal of Materials Research 19, no. 3 (March 2004): 921–29. http://dx.doi.org/10.1557/jmr.2004.19.3.921.

Full text

Abstract:

Several new bulk metallic glasses based on Fe–Y–Zr–(Co, Cr, Al)–Mo–B, which have a glass-forming ability superior to the best composition Fe61Zr10Co7Mo5W2B15 reported recently, have been successfully developed. The as-cast bulk amorphous alloys showed a distinctly high thermal stability with glass-transition temperatures above 900 K, supercooled liquid regions above 60 K, and high strength with Vickers hardness values larger than HV 1200. The suppression of the growth of primary phases in the molten liquids and the resultant low liquidus temperatures were found to be responsible for the superior glass-forming ability in these new alloys. It was found that the addition of 2% Y not only facilitated bulk glass formation, but the neutralizing effect of Y with oxygen in the molten liquids also improved the manufacturability of these amorphous alloys.

APA, Harvard, Vancouver, ISO, and other styles

33

Marenych, Olexandra, and Andrii Kostryzhev. "Strengthening Mechanisms in Nickel-Copper Alloys: A Review." Metals 10, no. 10 (October 12, 2020): 1358. http://dx.doi.org/10.3390/met10101358.

Full text

Abstract:

Nickel-Copper (Ni-Cu) alloys exhibit simultaneously high strength and toughness, excellent corrosion resistance, and may show good wear resistance. Therefore, they are widely used in the chemical, oil, and marine industries for manufacturing of various components of equipment, such as: drill collars, pumps, valves, impellers, fixtures, pipes, and, particularly, propeller shafts of marine vessels. Processing technology includes bar forging, plate and tube rolling, wire drawing followed by heat treatment (for certain alloy compositions). Growing demand for properties improvement at a reduced cost initiate developments of new alloy chemistries and processing technologies, which require a revision of the microstructure-properties relationship. This work is dedicate to analysis of publicly available data for the microstructure, mechanical properties and strengthening mechanisms in Ni-Cu alloys. The effects of composition (Ti, Al, Mn, Cr, Mo, Co contents) and heat treatment on grain refinement, solid solution, precipitation strengthening, and work hardening are discussed.

APA, Harvard, Vancouver, ISO, and other styles

34

Singh, Mahander Pratap, Emmanuel Femi Olu, Prafull Pandey, and Kamanio Chattopadhyay. "Thermophysical and magnetic properties of Co-Ni-Mo-Al-Ta class of tungsten free Co-based superalloys." Journal of Alloys and Compounds 879 (October 2021): 160379. http://dx.doi.org/10.1016/j.jallcom.2021.160379.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

RODEWALD, W., P. SCHREY, and B. WALL. "MICROSTRUCTURE AND TEMPERATURE STABILITY OF SINTERED Nd-Dy-Fe-Co-Mo-Al-B MAGNETS." International Journal of Modern Physics B 07, no. 01n03 (January 1993): 721–24. http://dx.doi.org/10.1142/s0217979293001517.

Full text

Abstract:

Simultaneous additions of Co and Mo or V, respectively, to Nd-Dy-Fe-Al-B alloys improve the temperature stability of sintered magnets. The intrinsic coercivity at 150 ºC amounts to 9 kA/cm for magnets with a Dy-content of 3 at.%. Hence magnets with a load line, B/μoH=−2, may be operated at temperatures up to 200 ºC. The additions of Mo or of V result in the precipitation of a tetragonal Mo2FeB2 compound, a=0.58 nm, c=0.32 nm, or of a tetragonal V3–xFexB2 compound, x=0.2...1.2, within the (Nd, Dy)2(Fe, Co, A1)14B grains. The dimensions of the precipitates range from 10 to 600 nm. Besides Mo2FeB2- or V3–xFex+B2-grains, respectively, with dimensions up to 10 μm were observed within the Nd-rich constituents. The intrinsic coercivity, however, is determined by nucleation of reversed domains. The addition of Co results in a partial replacement of the Nd-Fe solid solution by the Nd3Co compound. Corrosion tests revealed, that the corrosion behaviour is not improved significantly and depends much more on the surface treatment.

APA, Harvard, Vancouver, ISO, and other styles

36

Li, Jia Lian, Shu Liang Wang, Xue Qin, Yu Heng Li, Lu Jiang Zhou, Yuan Hua Lin, and Xing Jun Liu. "Thermodynamic Database of the Phase Diagrams in the Sc-X Binary Systems." Materials Science Forum 850 (March 2016): 439–43. http://dx.doi.org/10.4028/www.scientific.net/msf.850.439.

Full text

Abstract:

Sc-based alloys have been used as aero-structures materials, and Sc addition on wrought alloys has positive effects on weldability and welding properties. Phase diagrams play an effective role during the development of new type of alloy with good properties. Therefore, to establish the thermodynamic database of Sc-X binary systems is important and necessary.In the present work, the thermodynamic assessments of Sc-X (Ag, B, Cr, Er, Gd, Mo, Th, W, Y, Zr) binary systems was carried out by using CALPHAD (Calculation of Phase Diagrams) method based on the experimental data including thermodynamic properties and phase equilibria. The Gibbs free energies of the solution phases were described by the sub-regular solution model with the Redlich-Kister equation, and those of the intermetallic compounds were described by the sub-lattice model. A set of self-consistent thermodynamic parameters were derived for describing the Gibbs free energies of each solution phase and intermetallic compound. The calculated phase diagrams and thermodynamic properties are in good agreement with experimental data. The thermodynamic database of the Sc-X (Al, Ag, B, Ca, Co, Cr, Cu, Er, Fe, Ga, Gd, Ge, La, Li, Mg, Mn, Mo, Ni, Pb, Pd, Ru, Sn, Th, W, Y, Zn, Zr) binary systems have been developed, which can provide much important thermodynamic information for multicomponent Al-Sc based alloys.

APA, Harvard, Vancouver, ISO, and other styles

37

Hall, E. L., and M. R. Jackson. "Microstructural Characterization of Rapidly Solidified Carbide-Containing Ni-Base Superalloys." Proceedings, annual meeting, Electron Microscopy Society of America 43 (August 1985): 48–49. http://dx.doi.org/10.1017/s0424820100117315.

Full text

Abstract:

The temperature capability of nickel-base superalloys which are used in aircraft turbines may be able to be extended if novel microstructures can be produced in these materials by rapid solidification. The primary goal of these efforts is to achieve a fine dispersion of small precipitates which are stable at high temperature in the alloys. One class of alloys which seem particularly promising are the eutectic superalloys, which solidify via a eutectic reaction in which a γ- γ’ matrix containing MC carbides is formed. For this investigation, alloys which contained either Ta, Ti, or V as the primary carbide former were studied. In all cases, the base alloy consisted of Ni-4%Co-4%Cr-5.5%Al-2%Mo-3%W-1.5%Re-0.3%C in weight percent. The alloys additionally contained either 9% Ta, 5.5% Ti, or 4.5% V (subsequently referred to as alloys A, B, and C, respectively). The alloys were rapidly solidified by melt-spinning in vacuum.

APA, Harvard, Vancouver, ISO, and other styles

38

Zhu, Sheng, Wen Bo Du, Xiao Ming Wang, and Guo Feng Han. "High Mixing Entropy Alloys Design with High Anticorrosion and Wear-Resistance Properties." Advanced Materials Research 815 (October 2013): 19–24. http://dx.doi.org/10.4028/www.scientific.net/amr.815.19.

Full text

Abstract:

High entropy alloys emerge as a new type of advanced metallic materials, which have received increasing attentions from material engineers around the world. In addition to high entropy effect based on equiatomic or near-equiatomic and containing five or more principal elements, they exhibit a cocktail effect resulting from interactions among all the elements and the indirect effects of the various elements on the performances. In this study, according to high entropy alloy design principles, corrosion-resistant elements such as Al, Ni, Cr and Mo were used to improve the anticorrosion property, Fe, Co, B and Si as solid solution elements were added to promote the formation of solid solutions with simple structure, and the wear-resisting property increased.

APA, Harvard, Vancouver, ISO, and other styles

39

Kwon, Oh Jib, Young Kook Lee, Jin Ju Lee, Yu Chan Kim, and Eric Fleury. "Magnetic and Mechanical Properties of Fe-Co-B-Si-Nb-M (M = Al, V, Mo,) Bulk Metallic Glasses." Advanced Materials Research 26-28 (October 2007): 743–46. http://dx.doi.org/10.4028/www.scientific.net/amr.26-28.743.

Full text

Abstract:

The compositional dependency of the glass forming ability (GFA), magnetic and mechanical properties of the Fe52Co20B20Si4Nb4 bulk metallic glass was investigated by means of the partial substitution of Co either by Al, V or Mo elements. A minor concentration of these elements enabled an increase of the GFA and fully amorphous rods of 4 mm diameter were successfully fabricated for the Fe52Co19B20Si4Nb4Al1, Fe52Co17B20Si4Nb4V3 and Fe52Co17B20Si4Nb4Mo3 alloys. While the addition of Al resulted in an increase of the magnetization saturation, V appeared as the most effective element to enhance the plastic deformation under compression.

APA, Harvard, Vancouver, ISO, and other styles

40

Idczak, Rafał, Robert Konieczny, and Jan Chojcan. "Mean hyperfine fields at 57Fe in dilute iron-based alloys studied by Mössbauer spectroscopy." Nukleonika 60, no. 1 (March 1, 2015): 39–42. http://dx.doi.org/10.1515/nuka-2015-0010.

Full text

Abstract:

Abstract The room temperature Mössbauer spectra of 57Fe were measured for numerous dilute iron-based alloys Fe1−xDx (D = Al, Co, Cr, Mn, Mo, Ni, Os, Pt, Re, Ru, Ta, Ti, V, W, Zn), annealed at 1270 K for 2 h before the measurements. The spectra were analyzed using the Hesse–Rübartsch method in order to determine the mean hyperfine magnetic field <B> at the 57Fe nuclei as a function of concentration x of the minority component of the alloy. As the binary alloys are one-faze solid solutions of an element D in iron, a linear relationship between <B> and x is observed. The result supports the suggestion that Mössbauer spectroscopy is a useful tool for the study of dissolution of different elements in iron.

APA, Harvard, Vancouver, ISO, and other styles

41

Niu, Ben, Zhenhua Wang, Qing Wang, Qianfu Pan, Chuang Dong, Ruiqian Zhang, Huiqun Liu, Peter K. Liaw, and Wei Xu. "Dual-phase synergetic precipitation in Nb/Ta/Zr co-modified Fe–Cr–Al–Mo alloy." Intermetallics 124 (September 2020): 106848. http://dx.doi.org/10.1016/j.intermet.2020.106848.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Le Nué, Charline, Jean Marc Cloué, Marie Hélène Mathon, Sylvain Puech, Denis Béchet, and Denis Delagnes. "Relationship between the Yield Strength-Fracture Toughness Balance and the Multiscale Microstructure of a Maraging Stainless Steel for Aircraft Applications." Materials Science Forum 879 (November 2016): 413–18. http://dx.doi.org/10.4028/www.scientific.net/msf.879.413.

Full text

Abstract:

Two grades of Fe-Cr-Ni-Al-Ti-Mo maraging steels, with a different titanium content, were investigated. Particular attention was given to the correlation between the precipitated phases and the yield strength. Synchrotron X-ray diffraction, small-angle neutron scattering and atom probe experiments were performed to determine the crystal structure, shape, size distribution, chemical composition, particle number density and volume fraction of precipitates. Both alloys show a strong increase in strength after an aging treatment, which is attributed to the co-precipitation of two different intermetallic phases. Strengthening by a single precipitation of β-Ni (Al,Ti) particles induces a saturation of yield strength around 1600 MPa above a volume fraction of 6 %. The improvement of yield strength is then obtained by introducing a nanoscale co-precipitation of η-Ni3(Ti,Al) phase.

APA, Harvard, Vancouver, ISO, and other styles

43

Zeisl, Stefan, and Ronald Schnitzer. "Cooling Rate Controlled Aging of a Co-Free Fe-Ni-Cr-Mo-Ti-Al Maraging Steel." Metals 12, no. 4 (March 22, 2022): 538. http://dx.doi.org/10.3390/met12040538.

Full text

Abstract:

Maraging steels are high-strength steels that are hardened by the formation of precipitates during an isothermal aging heat treatment. Depending on the aging temperature and time the cooling rate after holding can play a significant factor on the development of the microstructure and mechanical properties. This study seeks to show how the cooling time influences the precipitation hardening effect, austenite reversion and the development of hardness and impact toughness. The material was aged at a constant temperature using holding times of 0 h, 4 h and 15 h and cooled with different cooling rates resulting in cooling times of 7 h, 28 h and 56 h. The microstructure was characterized using a combination of electron backscatter diffraction, X-ray diffraction and atom probe tomography with cluster-based precipitate analysis. It is shown that the effect of the cooling time is strongly dependent on the holding time and that a longer cooling time can improve hardness and impact toughness.

APA, Harvard, Vancouver, ISO, and other styles

44

Gasan, Hakan, and Akin Ozcan. "New Eutectic High-Entropy Alloys Based on Co–Cr–Fe–Mo–Ni–Al: Design, Characterization and Mechanical Properties." Metals and Materials International 26, no. 8 (November 8, 2019): 1152–67. http://dx.doi.org/10.1007/s12540-019-00515-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Hahn, Junhee, Xiao Xiao, and Dong Bok Lee. "Oxidation of Ni-Cr-Co-Al-Mo-Ti-Re-Ta-W-Ru Single Crystals at 1000 ^oC in Air." Korean Journal of Metals and Materials 58, no. 4 (April 5, 2020): 234–46. http://dx.doi.org/10.3365/kjmm.2020.58.4.234.

Full text

Abstract:

Three kinds of Ni-based single crystals with the compositions of 63.8Ni-7.5Cr-5.1Co-4.8Al-1.9Mo- 0.9Ti-3Re-11.8Ta-1.2W, 61.4Ni-7.4Cr-5Co-4.8Al-1.8Mo-0.9Ti-3.1Re-11.6Ta-4W, and 60.9Ni-7.5Cr-5Co-4.8Al- 2Mo-1Ti-2.9Re-10.9Ta-1.2W-3.8Ru, in wt%, were cast in a Bridgman furnace. In the cast alloys, Cr, Co, Re, Mo, W, and Ru became microsegregated in dendrites consisting of γ-Ni, while Ni, Ta, and Al microsegregated in interdendrites consisting of eutectic γ/γ . The cast alloys were oxidized at 1000 oC up to 275 h in air to study the effect of alloying elements on high-temperature oxidation. The oxide scales consisted primarily of CrTaO4, with some NiCr2O4, NiO, and α-Al2O3. The oxidation resistance was dependent on the formation and continuity of the α-Al2O3 scale. Ta and W were beneficial, while Ru was harmful in improving the oxidation resistance. The selective oxidation of Al in dendrites led to the formation of thin, uniform α-Al2O3 scales, i.e., uniform oxidation. The competitive oxidation of active elements such as Al, Ti, and Ta in interdendrites led to the formation of porous, crack-susceptible oxide nodules, i.e., nodular oxidation. Less active elements such as Ru, Re, Ni, Co, Mo, W, and Cr tended to enrich in the vicinity of the oxide nodules. The oxidation progressed through the outward diffusion of cations and the inward diffusion of oxygen. This inward diffusion formed internal alumina islands, beneath the oxide scale.

APA, Harvard, Vancouver, ISO, and other styles

46

Kushnerov, O. I., and V. F. Bashev. "The effect of cooling rate on the magnetic properties of Cu-Fe-Ni multicomponent alloys with Al and Si additions." Journal of Physics and Electronics 26, no. 1 (December 3, 2018): 39–44. http://dx.doi.org/10.15421/331806.

Full text

Abstract:

The paper explores the structure and magnetic properties of multicomponent high-entropy Al-Cu-Fe-Ni-Si alloys in as-cast and splat-quenched state. This alloy system is characterized by the absence of expensive components, such as Co, V, Mo, Cr, usually used for the production of high-entropy alloys while its characteristics are not inferior to those of more expensive alloys. Components of the studied high-entropy alloys were selected taking into account both criteria for designing and estimating their phase composition, which are available in the literature and based on the calculations of the entropy and enthalpy of mixing, and the difference between atomic radii of components as well. The alloy films were fabricated by a known technique of splat-quenching. A cooling rate estimated by film thickness was ~ 106 K/s. Experimental results reveal that the studied alloys except the Al0.5CuFeNi one are multiphase, with the structure consisting of disordered BCC and FCC solid solutions. The Al0.5CuFeNi alloy has only FCC phase. The leading role in determining the type of solid solution formed in the studied high-entropy films obviously plays an element with the highest melting point. All of the investigated multicomponent films are soft magnetic materials as indicated by low values of coercivity, while most of the as-cast alloys are hard-magnetic.

APA, Harvard, Vancouver, ISO, and other styles

47

Yu, Zhu Huan, and Jun Feng Qiang. "Microsegregation Behavior of Single Crystal Superalloy." Advanced Materials Research 983 (June 2014): 121–26. http://dx.doi.org/10.4028/www.scientific.net/amr.983.121.

Full text

Abstract:

The major advancements in some mechanical properties of single crystal superalloys can be attributed to the carbon addition. The present study investigated the effect of carbon addition levels on the microsegregation behavior of single crystal superalloys. Quantitatative partitioning results indicated that typical single crystal superalloy segregation behavior for some elements such as W, Ni, Co, are all towards the dendrite core regions, while for elements of Al, Mo, Ta, Ti, Cr, partition towards the interdendrite regions. For all the alloys studied, the baseline alloy showed the most severe segregation degree, while the no carbon alloy the slightest. Furthermore, the segregation behavior of Ti and Ta were affected by the carbon additions, and that of W was greatly affected by the carbon levels.

APA, Harvard, Vancouver, ISO, and other styles

48

Naseem, Kashif, Hao Zhong, Hui Wang, Liuzhang Ouyang, and Min Zhu. "Promoting hydrogen generation via co-hydrolysis of Al and MgH2 catalyzed by Mo and B2O3." Journal of Alloys and Compounds 888 (December 2021): 161485. http://dx.doi.org/10.1016/j.jallcom.2021.161485.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Hu, Xian Xian, Xiao Gang Lu, and Yan Lin He. "Assessments of Impurity Diffusion Coefficients of Selected Pure Metals in Fcc Fe." Advanced Materials Research 936 (June 2014): 545–51. http://dx.doi.org/10.4028/www.scientific.net/amr.936.545.

Full text

Abstract:

Abstract: The atomic mobilities for impurity diffusion of Al, Au, Co, Cu, Mn, Mo, Nb, Ni, Pt, Sn and Zn in fcc Fe have been critically assessed based on the experimental diffusion coefficient data available in the literature. The impurity diffusion coefficients calculated from the atomic mobilities agree reasonably well with the reliable experimental data. This work provides a helpful guidance for the establishment of a general Fe-based mobility database to design new Fe-based alloys for practical purposes.

APA, Harvard, Vancouver, ISO, and other styles

50

Zhou, H. J., F. Xue, H. Chang, and Q. Feng. "Effect of Mo on microstructural characteristics and coarsening kinetics of γ' precipitates in Co–Al–W–Ta–Ti alloys." Journal of Materials Science & Technology 34, no. 5 (May 2018): 799–805. http://dx.doi.org/10.1016/j.jmst.2017.04.012.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Co-Mo-Al Alloys'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles