温度诱导的液-液结构转变对Sn-10％Bi合金凝固的影响

以温度诱导的液-液结构转变为切入点,研究了Sn-10％Bi合金经不同过热处理后凝固行为和凝固组织的变化.首先利用自制的定向凝固装置进行了液-液结构转变对Sn-10％Bi合金的定向凝固影响的研究.然后测定经不同过热处理的合金熔体相应的凝固曲线,并观察凝固组织.结果表明,相对于在结构转变前保温处理的熔体,经历了结构转变的合金熔体,凝固时所需过冷度增大,并且凝固组织显著细化；揭示了温度诱导液-液结构转变对合金凝固行为及组织有着明显影响.

Influence of Temperature-induced Liquid-liquid Structure Transition on Solidification Behavior of Sn-10%Bi Alloy

From the viewpoint of temperature-induced liquid-liquid structure transition(TI-LLST),the solidification behaviors and morphologies of Sn-10%Bi alloy under different melt overheating treatments were studied.The directional solidification experiments of Sn-10%Bi alloy were carried out to investigate the effect of the TI-LLST on directional solidification microstructure by using self-made unidirectional solidification device.The solidification curves of the melt before and after structure transition were mapped and its microstructure were observed.The results show that,compared with the kept temperature melt before the TI-LLST,the undercooling of the primary phase of the samples solidified from the melt experienced the TI-LLST increases,and the size of primary phase decreases markedly;TI-LLST affects the solidification behavior and microstructure remarkably.