材料期刊网

本文研究了热循环对Cu-Zn-Al合金马氏体相变的影响,其中包括热循环对相变热滞、转变特征温度及马氏体形貌的影响。由电阻-温度曲线表明M_s和A_f温度随热循环次数增加而升高;但M_f和A_s温度则保持不变。还可看到参加热循环的马氏体量随循环次数增加而减少。在300次左右达到饱和。用金相和电子显微镜研究了马氏体转变形貌的变化。发现淬火后马氏体的生长和收缩以两种方式同时进行,即连续式和爆发式两种。经过60次热循环后马氏体生长和收缩均以阶梯式分步进行。

The effect of thermal cycling between the M_f—A_f temperatures on the thermal hysteresis, temperature dependence, and the morphology of the martensitic transformation in Cu-Zn-Al alloy was studied. It showed that the hysteresis behaviour of cyclic transformation changed, M, and A_f temperature shifted to higher temperatures while the M_f and A_s temperatures remained constant. The amount of martensite undergoing cyclic transformation decreased. These changes appeared to saturate at 300 cycles and could be partly recovered during room temperature holding. The morphology and mode of transformation also changed. During the second cycling transformation occurred in two ways: martensite needles grow in a continuous manner and in a "burst" process. After 60 cycles no burst type transformation occurred during further cycling.