Статті в журналах: "Casting center"

1

Zenil, Ramses, Jose A. García, Gerardo A. Ruiz, Alejandro D. Basso, and Jorge Sicora. "Effect of cooling rate on the formation and distribution of carbides in nodular iron alloyed with Cr." MRS Proceedings 1485 (2012): 125–29. http://dx.doi.org/10.1557/opl.2013.280.

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ABSTRACTThis investigation deals with the effect of cooling rate on the formation of carbide nodular iron alloyed with 2.2 % Cr and equivalent carbon near 4.3%. In the experimental stage three Y-blocks of 1.5, 3 and 5.5 cm in thickness are poured in green sand molds. Castings are sectioned in two positions (wall and center samples) in order to determine the characteristics of the precipitated carbides (fraction, distribution and relative size) from surface to center and from the bottom to the top of the castings applying quantitative analysis of images. The obtained results show the presence of carbides in all of the castings. Finer carbides are obtained in the thinnest casting but with a high variation between the samples located in the wall and center. All castings present massive carbides in the last freezing zone (LFZ). Therefore the cooling rate associated with casting thick has an important effect on the fraction and distribution of carbides.

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2

SUN, ZHI, YANWEI SUI, AIHUI LIU, BANGSHENG LI, and JINGJIE GUO. "RESEARCH OF MECHANICAL PROPERTY GRADIENT DISTRIBUTION OF Al-Cu ALLOY IN CENTRIFUGAL CASTING." Surface Review and Letters 18, no. 06 (December 2011): 297–301. http://dx.doi.org/10.1142/s0218625x11014795.

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Al-Cu alloy castings are obtained using centrifugal casting. The regularity of mechanical property gradient distribution of Al-Cu alloy castings with the same centrifugal radius at different positions is investigated. The result shows that the tensile strength, yield strength, elongation and microscope hardness exhibit the following gradient distribution characteristic — high on both sides and low on the center. The trend of mechanical property gradient distribution of Al-Cu alloy increases with the increase in the rotation speed. Moreover, the mechanical properties of casting centerline two sides have asymmetry. The reason is that the grain size of casting centerline two sides and Al2Cu phase and Cu content change correspondingly.

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3

Lei, Tien Shou, Wen Shiung Chang, and Shyen Yang Dong. "The Effect of Fluid Convection on Microstructures of Directionally Solidified Castings." Materials Science Forum 508 (March 2006): 473–78. http://dx.doi.org/10.4028/www.scientific.net/msf.508.473.

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Fluid convection during solidification of castings will influence the final structures of the castings. A vertical cylindrical casting set-up has been designed to provide two zones of solidification simultaneously with two moving fronts directionally upward and directionally downward, respectively. This two zone directional solidification casting was composed of a cylindrical Furan sand mold with a water chilled center hole block at the center of the casting. Experimentally it was observed that the cooling rates at different locations of the downward zone were much more even than those of the upward one and this is considered to be the result of a more even temperature distribution along the downward front moving zone due to stronger fluid convection. Fluid convection tends to mix up the liquid and results in a more even temperature distribution and a lower degree of segregation of the element molybdenum which has a strong tendency to segregate to the carbide in ductile iron. The characteristics of the matrix microstructure and the growing direction of carbide of this directionally solidified ductile iron has been investigated with SEM and EBSD techniques.

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4

Cho, In Sung, Jeong Tae Kim, and Jeong Kil Choi. "Integrated Database Development for Casting Design and its Application to Casting Simulation." Materials Science Forum 783-786 (May 2014): 2142–47. http://dx.doi.org/10.4028/www.scientific.net/msf.783-786.2142.

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Development of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. For the shape database, a number of casting products are scanned by using by using industrial computer tomography and compiled to the shape database. Each shape data in the database has also parametric 3D modeling data, not only the product but also its casting design. If casting engineer want to design new casting, similar casting shape with casting design can be easily retrieved from the shape database, and easily modified and adapted to the new casting. Technical knowledge of the various casting processes and their manufacturing process of the castings were compiled and the search engine for the knowledge was developed. Database of thermophysical properties of the casting alloys were obtained by the experimental study or calculation based on CALPHAD approach, and the properties were used for the in-house computer simulation of casting process. The databases were linked with intelligent casting expert system developed in e-design center, KITECH. It is expected that the databases can help non casting experts to devise the casting and its process. Various examples of the application by using the databases were shown in the present study.

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5

Mohapatra, Shubhashree, Hrushikesh Sarangi, and Upendra Kumar Mohanty. "Effect of processing factors on the characteristics of centrifugal casting." Manufacturing Review 7 (2020): 26. http://dx.doi.org/10.1051/mfreview/2020024.

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Centrifugal castings are produced by pouring liquid metal into rotating moulds. It solidifies under the influence of centrifugal forces, directed from the center to the periphery of the mould on account of mould rotation, and exhibits directionality in solidification which helps to eliminate voids and discontinuities in the resultant casting, usually encountered in gravity castings. Also, a compositional gradient is sat up in the melt which can be monitored, to produce functionally graded materials (FGMs) of choice with multi-functionality. The pouring rate, pouring temperature, mould temperature, and mould material can be suitably selected and altered in isolation or in combination, to generate a desired thermal gradient in the melt which decides its cooling rate. The cooling rate of the melt has the greatest impact on the grain structure of the casting. On the other hand, the grain structure of the casting governs its mechanical performance and decides the suitability for any specific end-use. Thus, different processing factors influence the characteristics of centrifugal casting. In the present article, a sincere attempt is made to analyze the effect of these factors and to enumerate the role played by each one of these factors in deciding the centrifugal casting characteristics.

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6

An, Hanghang, Yan Ping Bao, Min Wang, Quan Yang, Xiang Hong Wang, and Yan Yin Dang. "High-efficiency continuous casting of GCr15 bearing steel bloom based on cooperative control technique of complex electromagnetic stirring and soft reduction." Metallurgical Research & Technology 116, no. 6 (2019): 621. http://dx.doi.org/10.1051/metal/2019051.

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GCr15 bearing steel exhibits comparatively serious center macro-segregation in the continuous casting of bloom with the increase of casting speed. In the present work, the influence of complex electromagnetic stirring (M + F-EMS) and mechanical soft reduction (MSR) on the center macro-segregation in the continuous casting of 220 × 260 mm blooms of GCr15 bearing steel have been comparatively investigated to increase casting speed in order to ensure a good internal quality. Based on numerical simulation and experiments, M + F-EMS and MSR have been comprehensively evaluated and compared by combination of industrial trials. The results show that center carbon segregation first decreases and then increases with the increase of casting speed in both processes without optimization. For M + F-EMS process, when casting speed increases from 0.75 to 0.85 m · min−1, the average degree of center carbon segregation decreases from 1.2 ∼ 1.26 to 1.18 ∼ 1.25 by asymmetrical optimization; with regard to combination of M + F-EMS and MSR process, when casting speed increases from 0.75 to 0.9 m · min−1, the average degree of center carbon segregation decreases from 1.2 ∼ 1.26 to 1.08 ∼ 1.1 and the solute element distribution becomes homogeneous by optimization. In comparison, significant reduction of the center macro-segregation with the increase of casting speed can be achieved for combination of M + F-EMS and MSR process, however, it is infeasible for M + F-EMS process in the present technology situation.

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7

Chang, Feng Ji, Wei Na Liu, Yu Jun Li, Meng Han Wu, Yu Bin Wu, and Xing Zhi Tian. "An Engineering Analysis and Research on Center Frame Structure Using Casting of Vehicle Radar Antenna Pedestal." Applied Mechanics and Materials 224 (November 2012): 7–10. http://dx.doi.org/10.4028/www.scientific.net/amm.224.7.

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According to the usage of vehicle radar antenna pedestal center frame, this article analyzes and compares the structure characteristic of welding and casting. We decide to adopt the casting structure and use special casting material ductile iron QT450-10. And we describe the casting material ductile iron QT450-10. Based on the center frame of using conditions, we analyze the deformation and stress of center frame by the finite element analysis software. The design is in line with the material allowable requirements and to meet the requirements of the system stiffness.

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8

Liu, Xiao Bo, and Wen Kang Yan. "Influence of Different Roll Casting Conditions on Casting Microstructure." Advanced Materials Research 652-654 (January 2013): 2432–36. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.2432.

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The changes of roll casting microstructure under different casting conditions on experimental casting machine was studied, which showed that solidification microstructure is different with different casting speed and thickness. When the casting speed is 1.3m/min,the thickness of strip is 6mm, coarse columnar grain dominates the solidification structure; when it continuously increases to 4m/min, the thickness of strip is 3mm, aluminum strip shows as hybrid organization with columnar grains in two sides and small equiaxed grains in the center; when the casting speed is over 12m/min,the thickness of strip is 1.75mm, columnar grains all convert into equiaxed grains in solidification structure. The deformation microstructures are different with the different casting speed and thickness of strip. When the casting speed is 0.9m/min, the thickness of strip is 6mm, typical processing flow lines come into being along longitudinal direction and transverse direction shows as squashed grains without re-crystallization. When the casting speed is 5.4m/min, the thickness of strip is 2.5mm, microstructure of aluminum strip becomes chevron organization from columnar crystal, there is a condensate in the center of aluminum strip, and the deformation of outer metal is more serious than inner, incomplete dynamic recrystallized grains come into being in the outer metal of the aluminum strip.

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9

Žbontar, Matic, Mitja Petrič, and Primož Mrvar. "The Influence of Cooling Rate on Microstructure and Mechanical Properties of AlSi9Cu3." Metals 11, no. 2 (January 21, 2021): 186. http://dx.doi.org/10.3390/met11020186.

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The aim of this study was to determine the correlation between the size and the distribution of microstructural constituents and their cooling rate, as well as the correlation between the mechanical properties and the cooling rate of AlSi9Cu3 aluminum alloy when cast in high-pressure die casting (HPDC) conditions. In other words, the ultimate goal of the research was to determine the mechanical properties for a casting at different cooling rates. Castings with different wall thicknesses were chosen, and different cooling rates were assumed for each one. Castings from industrial technological practice were systematically chosen, and probes were extracted from those castings for the characterization of their mechanical properties. Special non-standard cylinders were created on which compressive tests were carried out. The uniqueness of this research lies in the fact that the diameters of the designed cylinders were in direct correlation to the actual wall thickness of the castings. This is important because the solidification of metal in the die cavity is complex, in that the cooling rates are higher on the surface of the casting than in the center. Local in-casting cooling rates were determined using numerical simulations. It was discovered that with increasing cooling rates from 60 K/s to 125 K/s the values for strength at 5% deformation increased on average from 261 MPa to 335 MPa.

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10

Chen, Wei Ping, Li Wei Zhou, Wen Hui Li, and Zhe Liu. "Thermal Analysis of Solidification Process and Mechanical Properties in Heavy Section Ductile Iron Casting." Advanced Materials Research 750-752 (August 2013): 454–61. http://dx.doi.org/10.4028/www.scientific.net/amr.750-752.454.

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A heavy section ductile casting (HSDIC) with dimensions of Φ590 mm×800 mm was prepared. Cooling curves at the center, at 85 mm from the center, at 170 mm from the center and at 255 mm from the center of the casting were recorded and analyzed. The results show that the precipitation of initial graphite, nucleation of eutectic cell and mass eutectic reaction at 255 mm from the center were all earlier than the other three locations. Moreover, it takes the longest time of 53 minutes of recalescence at 170 mm from the center with the highest temperature rise of 7 °C, though the cooling rate at this location is not the lowest in the casting, the mechanical properties are the worst. In addition, the largest amount of chunky graphite appears at 170 mm from the center.

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11

Puga, Hélder, Joaquim Barbosa, and Joana Oliveira. "Use of Acoustic Energy in Sand Casting of Aluminium Alloys." Advanced Materials Research 690-693 (May 2013): 2366–70. http://dx.doi.org/10.4028/www.scientific.net/amr.690-693.2366.

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During the last years, some researchers have focused the development of ultrasonic microstructure refinement /modification techniques of die-casting aluminium alloys, to improve their properties. The developed techniques are highly efficient when applied to the die-casting process, but their capability with sand and ceramic moulding are unknown. Sand/ceramic aluminium castings are prone to coarse microstructure, porosities and inclusions due to low cooling rates and turbulent gravity pouring, and suitable processing techniques are required to eliminate those drawbacks. This article reports some results of a research work aiming the development of a reliable, low-cost and environmentally friend casting process, for geometrically complex and massive high strength sand/ceramic aluminium castings, to eliminate traditional soundness related defects and simultaneously promote the development of refined microstructures. The article presents the effect of applying ultrasound to AlSi9Cu3 alloy during solidification on a sand mould on the resultant microstructure. Results include microstructure characterization and its relationship with thermal analysis data collected from the center of the cast samples during cooling.

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12

Fu, Zhen Nan, and Shou Mei Xiong. "Microstructure Simulation of Die Casting Magnesium Alloy." Materials Science Forum 575-578 (April 2008): 135–40. http://dx.doi.org/10.4028/www.scientific.net/msf.575-578.135.

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A cellular automaton (CA) based model for two-dimensional simulation of the grain morphology of high pressure die casting magnesium alloy was developed. The heterogeneous nucleation, the solute redistribution both in liquid and solid, the interface curvature and the growth anisotropy during solidification were also considered in the model. By fitting the curve of grain density distribution, parameters of continuous nucleation equation based on Gaussian distribution were calculated. The microstructure simulation of step-shape die castings of AM50 magnesium alloy was studied. The metallographic microstructure of the castings at the surface and center of three steps with different initial die temperature was investigated. The simulation results were compared with the experimental results and they were in good agreement on average grain size.

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13

Gao, Xiangzhou, Shufeng Yang, Jingshe Li, and Hang Liao. "Numerical Simulation on Optimization of Center Segregation for 50CrMo Structural Alloy Steel." High Temperature Materials and Processes 35, no. 6 (June 1, 2016): 583–89. http://dx.doi.org/10.1515/htmp-2015-0026.

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AbstractTo improve the center segregation of billet for 50CrMo structural alloy steel, a 3D numerical model of solidification and heat transfer process for continuous casting had been established. The influence law of continuous casting process parameters on the secondary dendrite arm spacing (SDAS) and equiaxed crystal ratio had been obtained. It was shown that reducing superheat and casting speed and increasing the secondary cooling intensity could decrease SDAS. Reducing any one of the three parameters could increase the equiaxed crystal ratio. Adjusting only secondary cooling intensity could not make the SDAS and equiaxed crystal ratio change in the desired direction, but regulating the other two parameters could supply this gap. After optimizing the continuous casting process parameters of 50CrMo billet, the defect of center segregation was solved basically.

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14

Zhang, Song Yang, Mao Peng Geng, and Shui Sheng Xie. "Simulation of Temperature Field during Semi-Solid Magnesium Alloy Produced by Casting-Rolling Technology." Solid State Phenomena 141-143 (July 2008): 671–76. http://dx.doi.org/10.4028/www.scientific.net/ssp.141-143.671.

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The temperature fields during semi-solid magnesium alloy produced by casting-rolling technology has been simulated by finite element method on the basis of ANSYS. The temperature fields for different conditions were obtained, which is consistent with the experimental results. Results show that there is a high temperature field in the casting and rolling zone. The temperature fluctuates from the center to edge of the strip near the entry of the casting and rolling zone. but The temperature decreases gradually from the center to edge of the strip near the exit of the casting and rolling zone. There are some remarkable effects of the temperature of the casting and rolling, the velocity of the casting and rolling, the gap of two roll, the cooling of the roll and the diameter of the roll on the temperature field, which are in agreement with the experimental results.

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15

Sharma, Bharat. "Flash Prevention in HPDC." International Journal for Research in Applied Science and Engineering Technology 9, no. 8 (August 31, 2021): 1902–9. http://dx.doi.org/10.22214/ijraset.2021.37661.

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Abstract: Welcome to steady die casting solutions. We are at steady die casting solutions keep on continue to give die casting solutions. In this paper we will discuss how we can predict flash location in die and how we can correct before die making or after die making. We also discuss how we can calculate individual tie bar load when we load a die, tie bar load will change on each die changeover because of it’s center of gravity. We discuss how casting shot centroid will effect tie bar load which directly responsible for flash. All this things we try to explain with an example, I hope it will be help full. Thank you very much, “keep learning till death”. Keywords: Flash, tie bar, machine tonnage, machine center, die, hpdc, casting defect and clamping force

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16

Zhang, Zhi Qiang, Qi Chi Le та Jian Zhong Cui. "Direct Chill Casting of Φ500mm ZK60 Magnesium Alloy Billets under Low Frequency Electromagnetic Field". Materials Science Forum 686 (червень 2011): 26–29. http://dx.doi.org/10.4028/www.scientific.net/msf.686.26.

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Effects of low frequency electromagnetic field on surface quality, microstructure and hot-tearing tendency of direct chill casting of Φ500mm ZK60 magnesium alloy billets were investigated. The results show that with the application of the low frequency electromagnetic field, the surface quality of Φ500mm ZK60 magnesium alloy billets has been markedly improved, and the depth of cold fold is decreased. In the conventional direct chill casting, the microstructures of the billet, especially at the center, are coarse. The distribution of the grain size is non-uniform throughout the billet. From the edge to the center, the microstructure gradually changes from fine to coarse in all billets. However, under the low frequency electromagnetic casting, the microstructures of the billet is significantly refined, the distribution of the grains size is relatively uniform from the billets edge to the billets center. And it also shows that the hot-tearing tendency of direct chill casting Φ500mm ZK60 magnesium alloy billets under low frequency electromagnetic field is significantly reduced.

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17

Chen, Wei Ping, Zhe Liu, Yu Deng, Jie Luo, and Yong Cheng Chen. "Effect of Yttrium and Magnesium Segregation on Microstructure and Mechanical Properties of Heavy Section Ductile Iron Castings." Advanced Materials Research 295-297 (July 2011): 1010–16. http://dx.doi.org/10.4028/www.scientific.net/amr.295-297.1010.

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Ductile iron specimen with dimensions of Φ590mm×800mm were prepared by treating the melt with an yttrium-containing nodulizer. Cooling curves at four locations____the center location, the location 85mm distant from the center, the location 170mm distant from the center and the location 255mm distant from the center of the heavy ductile iron casting Φ590mm×800mm was obtained. The effect of yttrium and magnesium on microstructure and mechanical properties was investigated, and the factors on the distribution of chunky graphite in the specimen were discussed as well. The results show that the largest amount of chunky graphite and the lowest mechanical properties appear at the location 170mm distant from the center. Excessive yttrium and magnesium content at the location 170mm distant from the center is the main factor for the large amount of chunky graphite. The characteristics of the solidification mode____pasty solidification and the considerably long solidification of the casting are the basic reasons for the distribution of chunky graphite of the heavy ductile iron casting Φ590mm×800mm.

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18

Xiao, Ruoxiu, Jiayu Wang, Xinyi Xie, Fujian Guo, and Xiucheng Li. "3D Center Segregation Reconstruction of Steel Continuous Casting Slab." steel research international 90, no. 12 (October 7, 2019): 1900254. http://dx.doi.org/10.1002/srin.201900254.

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19

Li, Xin, Jie Sun, and Xiao Feng Xie. "Research on Scheme of the Continuous Casting Slab Internal Quality Inspection Based on BP Neural Network." Applied Mechanics and Materials 380-384 (August 2013): 4383–86. http://dx.doi.org/10.4028/www.scientific.net/amm.380-384.4383.

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The internal quality of continuous casting billet mainly refers to the low power structure, center segregation, inner crack and the levels of inclusions. It seriously affects the comprehensive performance of steel and rolling slab of the casting billet center segregation and crack existing. The influence rules of the slab internal quality about the process and the factors of equipment combining with field production data have been discussed in this paper. Then using the improved BP algorithm with added momentum item and the prediction model of central segregation of continuous casting billet base on BP artificial neural network have been built.

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20

Zuo, Qi Wei, Xia An, Jing Bo Yang, and Da Qiang Cang. "Effects of over Heat and Casting Speed on Quality of GCr15 Billet." Advanced Materials Research 997 (August 2014): 534–37. http://dx.doi.org/10.4028/www.scientific.net/amr.997.534.

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In order to improve the quality of the billets, the whole test proceedings by the comparison of the two casting conditions which one is over heat 20°C-30°C under casting speed 0.4m/min-0.6m/min and the other is over heat 10°C-15 °C under casting speed 1.3m/min-1.6m/min are checked during the produce process of GCr15 in some domestic steel-making plant. The results show that the average grade of general porosity decreases 1.0, the average grade of center porosity down 0.5, the average grade of center segregation fall 0.5 and the samples tested in hot upset forging perform better than before. According to the results, the latter is determined to be accepted.

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21

You, Ming, and Xiao Gang Diao. "Simulation of Casting Process for Ductile Iron Wind Generator Rotor Shaft." Advanced Materials Research 567 (September 2012): 141–45. http://dx.doi.org/10.4028/www.scientific.net/amr.567.141.

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Casting process of heavy section ductile iron wind generator rotor shaft was simulated by finite element software ProCAST. Gating systems was designed according to the structure of the casting. Solidification behavior of the casting was then analyzed. Defects, especially porosity, of the casting during solidification were predicted and hence casting process optimization has been performed based on the simulation results in order to avoid porosity in the casting. Results show that solidification time of the casting is more than 14h when cooled in sand mold. Porosity easily formed at the thermal center and in the middle of flange. Solidification time is evidently decreased with the help of chills. However, porosity tendency depends on the position of chills. A ductile iron rotor shaft casting with good quality was finally produced according to the simulation results.

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22

Rivero, H. D., José A. García, E. Cándido Atlatenco, Alejandro D. Basso, and J. Sicora. "Effect of the ratio Mo/Cr in the precipitation and distribution of carbides in alloyed nodular iron." MRS Proceedings 1485 (2012): 113–18. http://dx.doi.org/10.1557/opl.2013.278.

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ABSTRACTThis investigation deals with the effect of 2/0, 1/1 and 1/0.5 Cr/Mo ratios on the local fraction, distribution and the comparative size of carbides precipitated in cast nodular iron. “Y” block castings with a thickness of 1.5 cm are cast in green sand molds. Two samples are cut from each casting, one located on the center and another on the wall. The carbide volume fraction is evaluated by a digital analysis system. Each sample is analyzed in three zones: bottom, middle and top. Carbide mappings are generated according to the average local carbide fraction in order to get the distribution of carbides on the casting. Results show that higher volume fractions of carbides precipitate for the ratio 2/0 of Cr/Mo with values between 28.5 and 19.5%. The lowest fraction of carbides is presented in nodular iron alloyed with a Cr/Mo ratio of 1/1 between 6.5 and 4.6%. Also a very heterogeneous distribution of the carbides is observed in the three alloys and massive carbides are observed in the last freezing zone of the castings.

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23

Zhang, Zhi Qiang, Qi Chi Le, and Jian Zhong Cui. "Effect of Physical Fields on Solidification Structures of DC Casting AZ80 Magnesium Alloy Billets." Applied Mechanics and Materials 105-107 (September 2011): 1616–19. http://dx.doi.org/10.4028/www.scientific.net/amm.105-107.1616.

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AZ80 magnesium alloy was semi-continuously cast under different physical fields which were conventional direct chill (DC) casting, low frequency electromagnetic casting (LFEC), ultrasonic casting (USC) and electromagnetic-ultrasonic combined casting (ECUC), respectively. The effect of different physical fields on solidification structures of AZ80 alloys was investigated. The results show that compared with the conventional DC casting, structures of AZ80 alloys billets cast with LFEC and USC have been greatly refined. The effective refinement takes place in the edge of billets when LFEC is applied. However, the effective refinement takes place in the center of billets when USC is applied. When combination of low frequency electromagnetic and ultrasonic fields is applied during semi-continuous casting AZ80 magnesium alloy billet, structures of AZ80 alloys are refined significantly in the whole billets everywhere and more uniform.

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24

Su, Li Ping, Jian Min Zeng, Jun Chen, and Wu Kui Gan. "Research on Simplified Reverse Method for Interfacial Heat Transfer Coefficient (IHTC)." Applied Mechanics and Materials 268-270 (December 2012): 974–77. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.974.

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The success of numerical simulation of solidification process depends to a large extent on boundary condition. Interfacial heat transfer coefficient (IHTC) can be used to measure heat resistance between casting and mold. Boundary condition of casting and mold varies with the temperatures during solidification process. However, determination of heat exchange on the boundary is very complicated. A new simple reverse method has been introduced in this paper. A casting with simple geometry acts as the standard sample and a thermal couple records the temperature history at the center of the casting during solidification. The solidification simulation of the casting was conducted with different IHTCs. The equivalent IHTC that best fits the measured temperature can be determined by comparing the measured cooling curve with the calculated one.

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25

Hallaj-Moghaddam, Mohammad, Ali Moradi, Mohammad Hosein Ebrahimzadeh, and Seyed Reza Habibzadeh Shojaie. "Ponseti Casting for Severe Club Foot Deformity: Are Clinical Outcomes Promising?" Advances in Orthopedics 2015 (2015): 1–5. http://dx.doi.org/10.1155/2015/821690.

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Between 2007 and 2010, a prospective study was done on 85 patients with severe idiopathic nonsyndromic clubfeet, in our center. Demographic features, severity of the deformity before and after serial casting according to Diméglio classification, and complications were assessed. The mean age of the patients was 8 days and 69% were male. The mean follow-up period was 26 months. The average number of castings used to correct the deformity was 5.7 times (range: 4 to 8). Tenotomy was performed in 76 (89.4%) of the feet. In all patients, plantigrade foot was achieved. Tenotomy occurred more in patients with higher Diméglio scores. Although patients who underwent Achilles tenotomy began to walk later than those who did not (13±7.2versus9.2±18), it was not significant (P=0.06). Relapse rate, at the end of follow-up, was 27.1%. Diméglio score before casting was16±3.4and at the end of follow-up it was1.6±6.2. The patients with bilateral clubfeet had inferior final outcome compared to those with unilateral clubfoot. Eighty percent of parents’ were completely satisfied with their child's gait and foot appearance (94.1%). Ponseti method of manipulation and casting is a valuable technique in severe club foot as well as in common types.

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26

Takagi, Masaaki, Haruo Houjoue, and Tomoki Shibata. "Improvement of center segregation of continuous casting with electro-magnetic stirrer." DENKI-SEIKO[ELECTRIC FURNACE STEEL] 58, no. 1 (1987): 36–44. http://dx.doi.org/10.4262/denkiseiko.58.36.

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27

Long, Mujun, and Dengfu Chen. "Study on Mitigating Center Macro-Segregation During Steel Continuous Casting Process." steel research international 82, no. 7 (April 21, 2011): 847–56. http://dx.doi.org/10.1002/srin.201100085.

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28

Groszkiewicz, Dan, and Brent Warren. "Alcoa's Michigan Casting Center runs the business from the bottom up." Journal of Organizational Excellence 25, no. 2 (2006): 13–23. http://dx.doi.org/10.1002/joe.20086.

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29

Suzuki, M., K. Kimura, A. Kawami, and M. Mizutani. "Improvement in center segregation of high carbon Steel continuous casting blooms." Revue de Métallurgie 89, no. 1 (January 1992): 83–92. http://dx.doi.org/10.1051/metal/199289010083.

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30

Jiang, Dongbin, and Miaoyong Zhu. "Center Segregation with Final Electromagnetic Stirring in Billet Continuous Casting Process." Metallurgical and Materials Transactions B 48, no. 1 (November 28, 2016): 444–55. http://dx.doi.org/10.1007/s11663-016-0864-x.

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31

Nikitenko, I., O. Starik, and M. Kutsevol. "RESULTS OF A PETROGRAPHIC STUDY OF THE BRONZE AGE CASTING MOLDS FINDS." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 2 (89) (2020): 28–35. http://dx.doi.org/10.17721/1728-2713.89.04.

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The present article is devoted to the mineralogical and petrographic research of raw materials of the collection of casting molds of the Bronze Age, found by the expedition of Dnipropetrovsk National Historical Museum named after D.I. Yavornytskyi during the excavations of the archaeological monument of Tokivske-1, located near the village Tokivske of Apostolove Rayon, Dnipropetrovsk Oblast. The finding of casting molds is of great importance, since it can be the evidence of bronze foundry production existence in the territory of the monument, which until now was regarded only as a megalithic place of worship. Provenance determination of the raw materials of casting molds can help to identify the role of Tokivske-1 in the system of metalworking cells of the Sabatynivska culture time (XVI–XIII centuries BC) and to establish its links with the ancient centers of mining of stone raw materials. According to previous petrographic studies, it is known that stone molds were made mainly of talc-chlorite-tremolite schists, since this material was easily processed and could withstand more castings than clay molds. Because of this, stone casting molds were highly valued, as well as bronze wares and ingots, and were transported over long distances. The purpose of the study was to establish links between the archaeological monument of Tokivske-1 and known mining and metallurgical centers of the Bronze Age, on the basis of mineralogical and petrographic research of raw materials of casting molds. As a result of the study of samples in thin sections and by X-ray diffraction analysis, it was established that the stone molds were mainly made of tremolite-chlorite-anthophyllite meta-ultrabazites. The determination of the origin of the rocks from which the casting molds were made was carried out by comparing their mineralogical and petrographic features with the features of similar rocks that form natural outcrops, as described in geological survey reports and literary data, and as observed by us in rock samples from natural outcrops in the Middle Dnipro and the Azov Sea areas. It was ascertained that the rocks from which all the casting molds of the collection were made do not form natural outcrops in the Middle Dnipro area and are not characteristic of the Kryvyi Rih area, which is considered to be the main center of raw materials extraction for the stone foundry forms of the Late Bronze Age on the territory of Ukraine. It was established that such rocks are more characteristic of the Western Azov Sea area, but one can not exclude another source of raw materials of the mold collection, in particular the Southern Urals, where bronze metallurgy was significantly developed and similar stone matrices were used. The obtained results suggest revision of established ideas on sources of supply of stone raw materials during the late Bronze Age.

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32

XU, Y. B., Y. M. YU, G. M. CAO, C. S. LI, G. D. WANG, and Z. Y. JIANG. "MICROSTRUCTURE AND CRYSTALLOGRAPHIC TEXTURE OF STRIP-CAST FE-3.2%SI STEEL SHEET." International Journal of Modern Physics B 22, no. 31n32 (December 30, 2008): 5762–67. http://dx.doi.org/10.1142/s0217979208051133.

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Fe -3.2% Si steel strips were produced using vertical type twin casting process, and the changes of microstructure and texture trough thickness direction were analyzed. The equiaxed grains of approximately 44.6µm were observed in the center layer, the great mass of columnar dendrite was formed near the surface, and the dendrite truck mainly developed in the transverse direction with respect to the casting direction of about 45° or less. From the subsurface to the center, the volume fraction of the Goss texture (110)[001] gradually decreases. The Goss {110} <001> components at the surface are two times those at the center layer, the {001} <100> components are three times those at the center layer, and the overall texture components are similar to that of the hot-rolled oriented silicon steel strip. The minor α texture could be found from the φ2=45° sections of ODF, and there is no remarkable composition segregation of Si element in the thickness direction of thin strip.

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33

Haga, Toshio, Maho Tsuchida, Hirotaka Sakata, Hisaki Watari, and Shinichi Nishida. "Globular Crystals in the Center of Roll Cast Aluminum Alloy Strips." Materials Science Forum 1007 (August 2020): 34–40. http://dx.doi.org/10.4028/www.scientific.net/msf.1007.34.

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This study investigated the crystallization position and formation mechanism of globular crystals at the center area in the thickness direction of aluminum alloy strips cast by a high-speed twin roll caster. Twin roll casters for single strips and clad strips were used, as well as twin roll casters equipped with a cooling slope. The globular crystals were formed from dividing arms of dendrites of the solidified layer facing the center area at the roll gap. The arms of isolated dendrite also divided. No globular crystals were formed at the interfaces of clad strips with different solidification temperatures because of the temperature gradient at the interface which inhibited division of the dendrite arms. It was demonstrated that globular crystals at the center area of the thickness direction were formed by dendrite-arm-dividing at the roll gap by the strip casting clad strip. Experiments by semisolid-strip casting with the cooling slope showed that globular crystals in the molten metal existed in the solidification layers.

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34

Kimura, Hiroyoshi. "Developing Innovative IT-Based Full Mold Casting." International Journal of Automation Technology 2, no. 4 (July 5, 2008): 289–96. http://dx.doi.org/10.20965/ijat.2008.p0289.

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Full mold casting (FMC), an effective manufacturing process for relatively large and small lot production, fits in well with information technology (IT) because FMC uses polystyrene foam for making patterns effectively shaped using CAD/CAM and a machining center, with IT making FMC extremely powerful in production. Kimura Chuzosho Co. which has been developing FMC since 1996, established original IT-based FMC in the early 2000s, maintaining domestic and international competitiveness in product quality, price, and cycle time as detailed in the sections this follow.

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35

Yang, Hai Bo, Guang Liang Wang, Xue Wen Chen, and De Ying Xu. "The Numerical Simulation and Optimization in Squeeze Casting of the Air Conditioning Compressor Front Cover." Advanced Materials Research 803 (September 2013): 317–20. http://dx.doi.org/10.4028/www.scientific.net/amr.803.317.

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Using the ProCast casting simulation software to make squeeze casting process simulation and analysis of the solidification process of the air conditioning compressor front cover and predict the location of gas volumes and shrinkage defects in the filling process. When adjusted the process parameters, volumes gas defects were eliminated, but there was still shrinkage occurs in the center. When imposed a secondary pressure on the central part, shrinkage was eliminated.

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36

Kim, Min-Seok, Hyoung-Wook Kim, Su-Hyeon Kim, and Shinji Kumai. "Role of Roll Separating Force in High-Speed Twin-Roll Casting of Aluminum Alloys." Metals 9, no. 6 (June 3, 2019): 645. http://dx.doi.org/10.3390/met9060645.

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The role of the roll separating force in the high-speed twin-roll casting of aluminum alloys was examined. In horizontal-type twin-roll casting, as the casting speed increased upon decreasing the roll separating force, the strip texture changed from a shear and rolling texture to a random texture. Direct temperature measurements during high-speed twin-roll casting showed that the roll separating force played a significant role in maintaining a good contact between the strip and the roll surface. This resulted in a high cooling rate around the roll nip and enabled the fabrication of a sound strip with a fine microstructure. Moreover, the high casting speed and lowered roll separating force gave a band structure consisting of fine globular grains in the mid-thickness region of the strip, which could be considered beneficial in the formation of a well-dispersed center segregation.

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37

Liao, Shuchi, Tianliang Zhai, and Hesheng Xia. "Highly adsorptive graphene aerogel microspheres with center-diverging microchannel structures." Journal of Materials Chemistry A 4, no. 3 (2016): 1068–77. http://dx.doi.org/10.1039/c5ta09540a.

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Novel graphene oxide aerogel microspheres (GOAMs) with well-defined “center-diverging microchannel” structures are obtained by a novel approach, i.e. a combination of electrospraying and freeze-casting. A formation mechanism, i.e. radial-directional freezing–thawing, was proposed. The reduced GOAMs exhibit excellent adsorption ability for various organic liquids and oils due to their highly hierarchical hydrophobic structure and a random packing effect.

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38

Pan, Hong, Guo Rong Wu, and Zhi Qiang Li. "Study on Quality Control Technology for Square/Round Billet in Panzhihua Steel." Advanced Materials Research 396-398 (November 2011): 1138–44. http://dx.doi.org/10.4028/www.scientific.net/amr.396-398.1138.

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The continuous casting technologies of the new square/round billet continuous caster in Panzhihua Steel have been studied. And on this basis, the effect of process parameters of primary cooling, mold powder, secondary cooling and electromagnetic stirring (EMS) on billet quality is investigated. With these studies, the continuous casting process is optimized, and the quality of square/round billet is improved as well. Comprehensive technologies for quality control of square/round billet in Panzhihua Steel have been proposed. The results of industrial tests show that the accept rate of surface quality for square billet is 98.44%, and that is 97.42% for round billet; the comprehensive rate below level 1.0 of internal defects of center porosity, center segregation and center cracks is more than 97%, and carbon segregation index is in the range of 0.93~1.09. The quality of square/round billet can meet the requirement of consumers absolutely.

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39

Lingayat, Maruti B., Sourabh S. Dhamale, and Gaurav B. Mate. "Ponseti method for treatment of idiopathic congenital talipes equinovarus at tertiary care center in India." International Journal of Research in Orthopaedics 7, no. 5 (August 25, 2021): 948. http://dx.doi.org/10.18203/issn.2455-4510.intjresorthop20213176.

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Background: Different treatment methods were tried with variable success rates but Ponseti method of serial casting and manipulation stood apart due to better understanding of foot biomechanics and became accepted choice of treatment worldwide.Methods: 50 patients were enrolled in the study out of which 40 were available for final follow-up. We studied 40 cases during October 2018 to December 2020 at Government Medical College, Aurangabad. Out of 40 cases 31 were male and 9 were female. 25 were unilateral and 15 were bilateral. All cases were idiopathic. 4 inches Plaster of Paris (POP) bandages were cut into half and such 2 inches POP bandages were used for casting. Tenotomies were performed under controlled environment of Operation Theater with general anaesthesia. Number 12 surgical blade was used. Dennis-Browne splint was used for maintenance of correction.Results: Out of total 55 feet studied, 10 feet (18.18%) required tendo Achilles tenotomy and 45 feet (81.82%) were treated with casting alone. There were 8 cases of relapses (20%). All relapsed cases were treated with repeat casting as per Ponseti protocol and none of them required repeat tenotomy. Complications related to plaster were minimal and there were no incidence of rocker bottom deformity.Conclusions: We conclude that in a low income developing country like India where case load is very high; Ponseti method is effective, inexpensive form of treatment with minimal complications. Need for extensive soft tissue procedures vastly reduced with this method.

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40

Yu, Lin Hui, Ji Dong Li, Anthony Shevchenko, Ming Gang Shen, Bao Guo Zhang, and Yi Yong Wang. "Effects of Continuous Casting Mould Vibration Feeding Strip on the Slab Structure." Applied Mechanics and Materials 727-728 (January 2015): 299–304. http://dx.doi.org/10.4028/www.scientific.net/amm.727-728.299.

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Continuous casting mold feeding steel strip is a new technology to improve the organization and the equiaxed crystal ratio of casting slab. It is researched in one Steel Mill taking low carbon steel Q235B, 250 * 1600mm billet as the research object. Effects of the vibration feeding steel strip on the slab structure and performance is studied. Results show that, porosity in the center of cast billet and macro segregation of dispersion decreased through the continuous casting mould vibration feeding steel strip technology, which can improve the quality of macro structure and reduce the chemical heterogeneity shaft direction to the regional and then improve the plasticity in thick rolling plate.

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41

Zhong, Hong, Liang Ying Wen, Zheng Peng, and Xiao Lin Zhang. "Simulation of Shell Thickness Distribution and Flow Field in Slab Continuous Casting Mold." Advanced Materials Research 146-147 (October 2010): 599–606. http://dx.doi.org/10.4028/www.scientific.net/amr.146-147.599.

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The shell distribution in the slab continuous casting mold has been simulated coupling a 3-D flow, temperature and volume fraction equations of the molten steel in FLUENT. The simulated results show that the flow velocity around the upper vortex center is decrease and the location of lower vortex center move down as the nozzle port angle increases. The simulated shell thickness in the center on the narrow face become thicker at meniscus and the shell thickness in the center on wide face decreases but the basic distributions of the shell tend to consistency as the nozzle port angle increases. The simulated results also show that the effects of solidified shell on flow field in mold is slight but the velocity of molten steel near the solidified shell. There are remelting near the impact regoins implicit our attentions in order to avoid breaking out.

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42

Ren, Ting Zhi, Xue Liang Shi, Xin Jin, and Pei Pei Han. "Study on Prediction of Reduction Position Based on Solidification and Heat Transfer Model." Applied Mechanics and Materials 487 (January 2014): 540–43. http://dx.doi.org/10.4028/www.scientific.net/amm.487.540.

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As one of the important parameters of dynamic soft reduction technology, reduction position seriously affects the using effect of this technology to decrease center segregation and porosity of continuous casting slabs. According to the actual production conditions, a two-dimensional solidification and heat transfer model was established. In order to obtain more accurate model, the heat transfer coefficient was amending by the pin shooting technique in measuring shell thickness. The laws of the effect of casting speed, superheat degree and specific water flow on reduction position were analyzed respectively and reduction positions were predicted in different working conditions based on the model. The experimental results show that the center segregation and porosity decreased obviously when it produces at the reduction position predicted by the model.

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43

Subroto, Tungky, Dmitry G. Eskin, Christopher Beckwith, Ivan Skalicky, Dan Roberts, Iakovos Tzanakis, and Koulis Pericleous. "Structure Refinement Upon Ultrasonic Melt Treatment in a DC Casting Launder." JOM 72, no. 11 (July 27, 2020): 4071–81. http://dx.doi.org/10.1007/s11837-020-04269-3.

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Abstract This work focuses on ultrasonic melt treatment (UST) in a launder upon pilot-scale direct chill (DC) casting of 152-mm-diameter billets from an AA6XXX alloy with Zr addition. Two casting temperatures (650°C and 665°C) were used to assess their effect on the resulting microstructure (grain size, particle size, and number density). Structure refinement results show the feasibility of UST in the DC casting launder. This is quantified through the corresponding reduction of grain size by around 50% in the billet center, or more towards the billet surface, reduction of the average Al3Zr particle size, and increase in the particle number density. A higher Al3Zr particle density was obtained when the alloy was cast at 665°C. Numerical simulation results and suggestions on how to improve the treatment quality of UST in DC casting launder are also provided.

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44

Cao, Tong You, Zhi Zheng Yang, Fan Cheng Yuan, Guo Yong Shuai, and Xin Quan Yang. "Study on the Relationship between Tensile Sample Lamination and Inner Quality of Q345 Slabs." Advanced Materials Research 295-297 (July 2011): 107–12. http://dx.doi.org/10.4028/www.scientific.net/amr.295-297.107.

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In order to find the relationship between tensile sample laminations and inner quality of Q345 slabs, casting trials in conditions of with and without EMS and different superheating have been carried out. It is found that slab inner quality can be improved a lot with EMS, center equiaxial grain ratio increases greatly. Lowering superheating leads to downgrading of center deviation, however, center equiaxial grain ratio increases not too much compared with EMS. Tensile samples produced by above-mentioned measures do not break in the center area.

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45

Tian, Peng, Xing Juan Wang, Li Guang Zhu, Yue Kai Xue, Wei Chen, and Wei Tian. "Numerical Simulation of High Frequency Electromagnetic Field in Soft Contact Continuous Casting Mold." Advanced Materials Research 482-484 (February 2012): 1534–37. http://dx.doi.org/10.4028/www.scientific.net/amr.482-484.1534.

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Based on electromagnetic theory, a billet model electromagnetic continuous casting of physical and mathematical were established. The three-dimensional mold for billet electromagnetic field was calculated by finite element method of ANSYS three-dimensional numerical simulation. Then the distribution of the electromagnetic field inside the crystal was gotten. At the same time, the influence of the power frequency and current strength on the intensity and distribution of the magnetic field were simulated. The result shows that the maximum of the electromagnetic flux density lies in the center of induction coil (steel surface in the center of the coil), and the magnetic flux density gradually reduces along the casting direction; the magnetic flux density increases while the power frequency is increasing; the magnetic flux density increases with the increasing of the current intensity.

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46

Szajnar, J., C. Baron, and A. Walasek. "Castings Dimensions Influence on the Alloyed Layer Thickness." Archives of Foundry Engineering 14, no. 1 (March 1, 2014): 107–12. http://dx.doi.org/10.2478/afe-2014-0024.

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Abstract The paper presents the results of simulation of alloy layer formation process on the model casting. The first aim of this study was to determine the influence of the location of the heat center on alloy layer’s thickness with the use of computer simulation. The second aim of this study was to predict the thickness of the layer. For changes of technological parameters, the distribution of temperature in the model casting and temperature changes in the characteristic points of the casting were found for established changes of technological parameters. Numerical calculations were performed using programs NovaFlow&Solid. The process of obtaining the alloy layer with good quality and proper thickness depends on: pouring temperature, time of premould hold at the temperature above 1300°C. The obtained results of simulation were loaded to authorial program Preforma 1.1 in order to determine the predicted thickness of the alloy casting.

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47

Wang, Hai Jun, Jun Xu, Zhi Feng Zhang, Bo Liang, and Ming Wei Gao. "Application Research of a New Coupling Stirring on DC Casting Process for Large-Sized Aluminum Ingots." Materials Science Forum 817 (April 2015): 48–54. http://dx.doi.org/10.4028/www.scientific.net/msf.817.48.

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A new coupling stirring technology was proposed and used to prepare direct chill (DC) ingots. Ingots of 7075 alloy were produced by a process of normal direct chill (NDC) casting and coupling-stirring direct chill (CDC) casting, respectively. The effect of the technology on the microstructures, composition segregation and mechanical properties of the ingots was investigated. The results showed that the temperature variation in the CDC casting process was more uniform than that in the NDC casting process. The grain of the CDC ingots was finer and more spherical than the grain of NDC ingots. The grain size at the edge, 1/2 radius, and center position in CDC ingot decrease by 28%, 22%, and 24% comparing with the grain size of the corresponding positions of NDC ingot, respectively. The billets with higher performance and lower macro-segregation were obtained in case of CDC. The flow stresses and the difference in different positions of DC ingots measured at Gleeble-1500D thermo-mechanical simulator decreased obviously when the coupling stirring technology is used in the casting process.

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48

Kessel, Martin, E. Loren Buhle, Simone Cohen, and Ueli Aebi. "Two distinct negative staining patterns of halobacterium cell envelopes." Proceedings, annual meeting, Electron Microscopy Society of America 45 (August 1987): 740–41. http://dx.doi.org/10.1017/s0424820100128018.

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The cell walls of Halobacteria are comprised of a 200,000MW sulphated glycoprotein, and by shadow casting are seen as a periodic hexagonal lattice of morphological units with a center to center spacing of approximately 140A. Preparations ot virtually salt tree envelopes from Halobacterium volcanii isolated from the Dead Sea, obtained by freezing and thawing the cells and suspension in 10mM CaCl2, have enabled high resolution analysis of the wall morphological units by negative staining.Envelopes of H. volcanii negatively stained with 1% uranyl acetate or 0.75% uranyl formate both at pH 4.5, have consistently resulted in two different images irrespective ot the stain used: a more prevalent “honeycomb” appearance of strong stain accumulating centers surrounded by regions ot stain exclusion (fig. 1 and fig. 3B); and a less common “true” negative staining with stain excluding rings (morphological units) and their stain accumulating centers lying in pools ot stain (Fig. 2 and 3A).

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49

Yuan, Fei, Dao Yuan Yang, Ting Wang, and Zhan Li. "Effects of Graphite Mold on Cooling Process of Fused AZS 33# Refractory." Key Engineering Materials 544 (March 2013): 110–14. http://dx.doi.org/10.4028/www.scientific.net/kem.544.110.

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This study analyzed effects of different thickness(TH) and thermal conductivity of graphite mold on temperature, liquid phase percentage and conductive heat flux, the cooling process of fused cast AZS 33# refractory could be simulated by using COMSOL Multiphysics software. The results show that: when the graphite mold thickness increased, surface center temperature and liquid phase area of casting decreased gradually, but conductive heat flux increased gradually, the cooling rate of casting increased, which were helpful to form fine crystals near the casting surface. When using conventional graphite mold, the optimum thickness was less than 40mm, while using the high thermal conductivity graphite mold, the optimum thickness was 50mm. So the rapid and homogeneous cooling process of casting could reduce the possibility of material crack and obtain fine crystals structure of material; comparing with conventional graphite mold, high thermal conductivity graphite mold was more beneficial to achieve uniform and fast cooling process to improve the performance and passing rate of products.

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50

Acierno, D., L. Di Maio, and G. Cuccurullo. "Analysis of Temperature Fields in Film Casting." Journal of Polymer Engineering 19, no. 2 (March 1, 1999): 75–94. http://dx.doi.org/10.1515/polyeng-1999-0202.

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Abstract Film casting extrusions were performed on polyethylene terephthalate) (PET) and polypropylene (PP) in a laboratory plant to evaluate the development of temperature profiles in the region from die to chill roll. This was done under different conditions of mass rate, drawing, and cooling. Thermal exchange of the film was evaluated by making use of an infrared thermography apparatus, which provides a bidimentional map of temperature profile for each testing condition. The different melt viscosity of the various polymers lead to more developed or less developed edge-beads. Therefore, at fixed working conditions, the resulting shapes of the temperature profiles and border effects differ for PET and PP. In particular, the temperatures in the transverse direction changed significantly from the edge to the center of the film, as shown in the thermographs. The thermal-fluid-dynamics behavior of polymeric-cast film during processing is discussed.

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