温度诱导液相结构转变对Pb-Sn合金凝固行为及组织的影响

在前期工作发现的某些合金熔体发生温度诱导非连续液-液结构转变的基础上,通过研究Pb-Sn共晶合金及Pb-Sn80%合金发生液-液结构转变前后熔体的凝固行为及组织,发现后者凝固过冷度较发生熔体结构转变前成倍增大,并导致凝固组织的明显细化.揭示了温度诱导非连续液-液结构转变对合金凝固行为及组织有着明显影响.

Effect of Temperature-induced Discontinuous Liquid Structure Change on the Solidification Behaviour and Solidified Structures of Pb-Sn Alloy

Our pormer investigation results showed that a temperature-induced discontinuous liquid-liquid (L-L) structure transition could occur in some binary alloys, at a temperature range much above the liquidus. In the present paper, the solidification behavior and microstructure of Pb-Sn eutectic and Pb-Sn80%, which have been melted below and above the L-L transition temperature, are investigated. It is found that solidification undercooling degree of the latter increases greatly and its solidification structure becomes finer evidently; temperature-induced discontinuous liquid structural change affects the solidification behavior and microstructure remarkably.