scholarly journals Influence of MHD - plasma melt processing on the structure and properties of cast aluminum alloy A390

2021 ◽  
Vol 100 (4) ◽  
pp. 24-32
Author(s):  
A.V. Narivsky ◽  
◽  
O.M. Smirnov ◽  
V.E. Panarin ◽  
Yu.P. Skorobagatko ◽  
...  

Growth of production of cast products and the desire of enterprises to reduce the cost of manufacturing metal products led to a significant increase in requirements for the structure and properties of aluminum alloys. Increasing of physical and mechanical properties of alloys is most effectively at the stages of their preparation in liquid state. At that, it is possible to affect effectively on the quality of cast metal by external actions on alloys, deep refining from gases and harmful impurities, active modifying of alloy, reducing or eliminating the negative impact of heredity of charge materials. The main disadvantage of the processes of structure refinement of alloys by using modifiers is instability of their results, which depends on various reasons. One of the most important reasons is providing conditions for the formation and preservation of active modifier particles in the melt volume. They are assimilating by liquid alloy and acting on crystal nucleus at crystallization. It is known that only ~10% particles are active of the total number of particles added with the ligature into the melt. Other particles dissolve in the melt, take away by the crystallization front, or push back on to intergranular boundaries. The considered methods of electromagnetic, MHD and plasma actions on liquid metal allow to refine and modify alloys without use of special reagents. The paper presents studying of the structure and properties of supereutectic silumin A390 after treatment in casting magnetodynamic installation (MDI) by submerged into melt the plasma argon jet and alternating electromagnetic field & magnetohydrodynamic (MHD) effects, including simultaneous combination. There are developed the scientific and technological bases of MHD-plasma processing of liquid hypereutectic silumin A390 and original equipment for their realization. It provides dispersed structure of solidified alloy. Thus, there is a significant decreasing of sizes both particles of primary silicon and dendrites of α-solid solution of aluminium. Also, strength characteristics of alloys increased to 10%, and elongation rises up in 1.5-2 times. Keywords: plasma jet, magnetodynamic installation (MDI), aluminum alloy, mechanical properties.

2014 ◽  
Vol 875-877 ◽  
pp. 1397-1405 ◽  
Author(s):  
G. Dinesh Babu ◽  
M. Nageswara Rao

Cast aluminum alloy 354 is used extensively for production of critical automobile components, owing to its excellent castability and attractive combination of mechanical properties after heat-treatment. With the advent of higher performance engines, there has been a steady demand to further improve the mechanical behavior of the castings made of the alloy, among others, through improvements in processing. The present study explores the possibility of improving tensile properties of the alloy by adopting certain non-conventional aging treatments. The non-conventional treatments include aging cycles similar to T6I4 and T6I6 referred to in the published literature, artificial aging in two steps instead of in single step and artificial aging preceded by various natural aging times. The results show that none of these non-conventional treatments leads to improvement of all tensile properties compared to the standard T61 treatment. Significant hardening takes place in the alloy due to natural aging. Changing the time of natural aging preceding artificial aging was found to have little effect on tensile properties.


2012 ◽  
Vol 445 ◽  
pp. 277-282 ◽  
Author(s):  
Xue Zhi Zhang ◽  
Kazi Ahmmed ◽  
Meng Wang ◽  
Henry Hu

In this study a number of thermal treatment schemes over a wide range of temperatures between 120˚ to 350˚ C and times (30 120 minutes) have been experimented in an effort to understand the effect of thermal treatment on tensile properties of vacuum die cast modified aluminum alloy A356. The results show that, the morphology of eutectic silicon has a sound effect on the tensile properties of the tested alloy. The content of magnesium-based intermetallic phases, their morphology and distribution throughout the matrix affect the mechanical properties of the aged alloy as well. The reduction in the strengths of the alloy treated at 350°C for two hours should be at least attributed partly to the absence of the magnesium-based intermetallic phase. However the presence of sufficient amount of magnesium intermetallic phase had played important role in strengthening the alloy thermally treated at 200°C for 90 minutes.


2021 ◽  
Vol 75 (1) ◽  
pp. 31-37
Author(s):  
Aleksandra Pataric ◽  
Marija Mihailovic ◽  
Branislav Markovic ◽  
Miroslav Sokic ◽  
Andreja Radovanovic ◽  
...  

Microstructure assessment is crucial for the design and production of high-quality alloys such as cast aluminum alloy ingots. Along with the effect of a more homogeneous microstructure to result in much better mechanical properties, better as-cast alloy quality indicates a higher efficiency of the aluminum alloys production process. During the aluminum alloy solidification process many microstructural defects can occur, which deteriorate the mechanical properties and hence decrease the usability of such an ingot. Application of the electromagnetic field during the vertical continuous casting process significantly reduces occurrence of these defects. In the present study, EN AW 7075 alloy samples were cast with and without application of an electromagnetic field and examined regarding the microstructure, electrical conductivity, and changes in the phase composition. The obtained results clearly show that it is possible to decrease or avoid casting defects by the electromagnetic field application as verified by the microstructure characterization and quantification, electrical conductivity tests and differential thermal analysis (DTA).


2016 ◽  
Vol 877 ◽  
pp. 56-61 ◽  
Author(s):  
Shinji Kumai ◽  
Yusuke Takayama ◽  
Ryoji Nakamura ◽  
Daisuke Shimosaka ◽  
Yohei Harada ◽  
...  

A horizontal-type twin roll casting method has been popular for producing aluminum alloy strips, however, it is characterized by a relatively low productivity (1~6 m/min). In contrast, a vertical-type high-speed twin-roll casting method possesses an extremely high productivity (60~120 m/min (1~2 m/s)) and an excellent heat extraction ability. The rapid cooling effect provided significant microstructure refinement and mechanical properties improvement in various kinds of cast aluminum alloy products. Not only “product to product recycling” but also “up-grade recycling” can be achieved by making good use of these merits. Two examples of application showing the potential of vertical-type high-speed twin roll casting method are presented. (1) Several kinds of Al-Si base alloy were cast into the strips. Not only strength and toughness but also formability was increased in the twin roll cast products. In particular, great improvement in deformability shows the potential of the twin-roll cast aluminum alloy products as substitutes for some wrought aluminum alloy products. (2) The vertical-type tandem twin-roll caster was able to fabricate a clad strip by single step. The A4045/A3003/A4045 aluminum alloy clad sheets produced by the twin-roll casting showed better mechanical properties than the conventional hot-roll bonded clad sheets.


2019 ◽  
Vol 69 (11) ◽  
pp. 536-540
Author(s):  
Masashi Takahashi ◽  
Masakatsu Maeda ◽  
Kensuke Yamamoto ◽  
Yoshinori Kamikubo ◽  
Yasuo Sugiura ◽  
...  

2022 ◽  
Vol 355 ◽  
pp. 01003
Author(s):  
Kangjie Yan ◽  
Weiqing Huang ◽  
Zhengxing Zuo ◽  
Jinxiang Liu ◽  
Peirong Ren ◽  
...  

In view of the non-uniform distribution of mechanical properties of cast aluminum alloy cylinder head, the mechanical properties evaluation and microstructure heterogeneity of cylinder head were studied. The results showed that the head plate position of the cylinder head has the best mechanical properties and microstructure characterization, followed by the floor plate and the thick partition plate. The mechanical properties of the floor plate position attenuate with increasing temperature. From 23°C to 300°C, the tensile strength and yield strength decrease in the same range, but the break elongation changes most obviously. The mechanical properties and microstructure characterization of cylinder head in-situ sampling satisfy the Hall-Petch relationship. If the required ultimate tensile strength is not less than 255MPa, the upper threshold of the grain size, by considering the error limit of the Hall-Petch relationship, is 603.4μm, and the upper threshold of secondary dendrite arm spacing is 69.1μm. Meanwhile, established the relationship between hardness and yield strength, the average error of the nonlinear model is 4.35%. The prediction accuracy of the nonlinear model is sufficient to meet the actual needs of the engineering.


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