Zr_(60)Al_(15)Ni_(25)大块非晶合金晶化动力学研究

Study of the crystallization kinetics of Zr_(60)Al_(15)Ni_ (25) bulk glassy alloy

通过等温示差扫描量热法研究了Zr6 0 Al1 5Ni2 5大块非晶合金的晶化动力学 .实验结果表明 ,晶化过程的孕育期很短 ,即使在 74 3K这样低的温度下也不过 0 .5 2min ,而放热峰宽 (反应整个晶化过程进行的时间 )却随退火温度的降低明显增大 ,这说明了结晶过程是一个晶核长大控制的过程 .Avrami指数表明在不同的退火温度 ,该合金的晶化机制发生了变化 .晶化机制的变化是由于合金原子在不同温度下的扩散能力相差很大所致 .

This paper reports the investigation on the crystallization kinetics of Zr 60Al 15Ni 25 bulk glassy alloy under isothermal annealing by differential scanning calorimetry. The results show that the incubation time is very small even at a low annealing temperature (743 K) and the exothermic peak width, reflecting the time for the actual crystallization process, increases greatly when annealing temperature decreases. This suggests a growth-controlled crystallization process. The Avrami exponents indicate that the crystallization mechanism changes at different annealing temperatures. The change of the crystallization mechanism is attributed to the great change of the mobility of atoms at different temperatures.