摘要
研究了紧耦合气雾化制粉过程中AlNiY合金熔滴的冷却行为以及非晶颗粒的形成机制。结果表明:(1)AlNiY合金非晶化的临界冷却速率大致为103K/s;(2)熔滴的冷却速率与直径成反比,当直径小于25μm时,熔滴达到临界冷却速率实现非晶化。当直径大于25μm时,熔滴无法获得非晶化临界冷却速率,只能发生形核结晶;(3)熔滴的非晶化还与雾化过程相关,由于熔滴破碎时的位置和温度不同,获得的冷却速率将不同,出现了相同直径(小于25μm)的颗粒存在非晶和结晶两种状态。
The cooling behavior of liquid droplets and the formation mechanism of amorphous were investigated by close-coupled gas atomization. The results indicate that the critical cooling rate （Re） is around 10^3K/s for the formation of amorphous powders of Al-based alloy, inversely proportional to liquid droplets＇ diametet. When the diameter of droplet is smaller than 25 μm, it may solidify into amorphous particle, while if larger than 25 μm it results in crystallization due to the departure to Rc. Furthermore, the amorphous formation of liquid droplet depends on the process of gas atomization. As a result, the final solidify can be amorphous or crystal even for the liquid droplets with the same diameter if the temperature and location of liquid droplets were different due to the different cooling rates.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2006年第6期866-870,共5页
Rare Metal Materials and Engineering
基金
国家自然科学基金资助项目(10476034)
关键词
气雾化
紧耦合喷嘴
冷却
非晶
粉末
gas atomization
close-coupled nozzle
cooling
amorphous
powder
