中文摘要：

运用电阻法和DSC热分析发现了CuSn30%合金熔体中存在不可逆的结构转变。在转变区间前后,通过熔体过热处理手段探索了这一结构变化对合金凝固过程及凝固组织的影响。结果表明,不可逆熔体结构的变化导致熔体凝固所需的过冷度增大,合金凝固组织变化明显,初生相和共析组织细化,分布弥散化。并从熔体结构转变角度对上述现象的作用机理进行了分析探讨。

英文摘要：

An abnormal irreversible change was found on ρ-T and DSC curves of liquid CuSn30% alloy,which suggested a liquid structural transition occurring in the melt.In the interval before and after,the effect of the structure change on solidification behavior and solidified structure were studied through superheat treatment.The results indicated that the irreversible structure change could lead to higher supercooling degree during solidification,and the primary phase and eutectoid phase became finer and more dispersive.The mechanism of above phenomena was also discussed briefly.