(上海交通大学 材料科学与工程学院，上海 200030)
摘 要: 设计了一种新的合金热裂行为测试系统。该系统通过数/模转换，用微机对凝固过程中的温度、 应力和收缩信号数据进行采集和进一步的处理，并描绘其曲线。实验结果表明，在正常凝固条件下，AZ91合金并不按平衡相图凝固，而是有共晶相析出；在合金凝固后期，存在一“冲击”收缩，是“冲击”收缩导致了合金凝固过程热裂的产生。
关键字: 微机测试； 热裂； 收缩； 凝固
hot-cracking testing of alloys
（School of Materials Science and Engineering,
Shanghai Jiaotong University， Shanghai 200030, P.R.China）
Abstract:A new method to test hot-cracking in metallic alloys was proposed. Through A/D conversion, the information of temperature, stress and shrinkage are collected and further treated, and their curves are drawn with microcomputer. The results indicate that AZ91 alloy does not solidify following the phase diagram under the experimental conditions, but precipitate eutectic; at the end of the alloys solidification, a “shock shrinkage” occurs, whcih leads to the hot cracking.
Key words: microcomputer testing; hot cracking; shrinkage; solidification
