A comparison of acoustic levitation with microgravity processing for containerless solidification of ternary Al–Cu–Sn alloy
A comparison of acoustic levitation with microgravity processing for containerless solidification of ternary Al–Cu–Sn alloy
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DOI：
10.1007/s00339-015-9151-y
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发表时间：
2015-04
期刊：
影响因子：
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通讯作者：
N. Yan;Z. Hong;D. Geng;B. Wei
中科院分区：
文献类型：
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作者：
N. Yan;Z. Hong;D. Geng;B. Wei
在超声悬浮和自由落体两种条件下，实现了Al-5% Cu-65% Sn三元非互溶合金的无容器快速凝固。超声悬浮的合金熔体在约122 K s-1的冷却速率下获得185 K（0.22 TL）的最大过冷度。合金液滴在落管中的冷却速率在102 ~ 104 K s-1之间变化。超声悬浮条件下的复合流动有效地抑制了宏观偏析。相反，宏观偏析变得明显，并形成不同层的核壳结构在自由落体。研究了无容器快速凝固过程中的组织形成机理，并与传统的静态凝固过程进行了对比。研究发现，通过控制合金的过冷度和冷却速率，可以调控液相分离和组织生长动力学。
The containerless rapid solidification of liquid ternary Al–5 %Cu–65 %Sn immiscible alloy was accomplished at both ultrasonic levitation and free fall conditions. A maximum undercooling of 185 K (0.22TL) was obtained for the ultrasonically levitated alloy melt at a cooling rate of about 122 K s−1. Meanwhile, the cooling rate of alloy droplets in drop tube varied from 102to 104K s−1. The macrosegregation was effectively suppressed through the complex melt flow under ultrasonic levitation condition. In contrast, macrosegregation became conspicuous and core–shell structures with different layers were formed during free fall. The microstructure formation mechanisms during rapid solidification at containerless states were investigated in comparison with the conventional static solidification process. It was found that the liquid phase separation and structural growth kinetics may be modulated by controlling both alloy undercooling and cooling rate.