紧耦合气雾化制备Al基非晶合金粉末  

Production of Al-based amorphous alloy powders by close-coupled gas atomization

作　　者：陈欣[1] 欧阳鸿武[1] 黄誓成[1] 黄伯云[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《北京科技大学学报》2008年第1期35-39,共5页Journal of University of Science and Technology Beijing

基　　金：国家自然科学基金资助项目(No.50574103;No.10476043)

摘　　要：开展了采用紧耦合气雾化方法制备Al基合金粉末的实验和理论研究.利用X射线衍射仪、差热分析仪、扫描电镜和透射电镜分析了粉末的表面形貌、显微组织和结构特征,根据气雾化过程中熔滴的破碎模式和冷却行为确定了Al基合金的非晶化临界冷却速率及相应粉末粒径.结果表明:气雾化粉末中存在部分非晶粉末,非晶粉末的粒径小于26μm;Al基合金的非晶化临界冷却速率大致为106K.s-1;雾化中熔体的破碎和冷却是两个相互耦合(矛盾)的过程,快速冷却(大于104K.s-1)极大地阻碍熔体的充分雾化,同时熔滴的破碎模式对其冷却行为具有显著的影响.目前紧耦合气雾化技术还只能制得非晶/晶态混合的Al基合金粉末.Theoretical and experimental studies on the production of M-based amorphous alloy powders by close-coupled gas atomization were carried out. The particle size, surface morphology and microstructure of the atomized powders were analyzed by XRD, SEM, TEM and DTA. The critical cooling rate for glass formation and corresponding powder diameter of the M-based alloy were determined in terms of the breakup mode and cooling behavior of melt during atomization. It is indicated that there are amorphous particles in the atomized M-based powders, which are basically below 26μm in diameter. The critical cooling rate for glass formation of the M-based alloy is about 106 K·s^-1 Melt atomization is such a complicated process that powders form under the coupling interaction of breakup and solidification, where rapid solidification （〉10^4 K·s^-1） restrains the breakup of melt; meanwhile, the breakup mode of melt has great influences on solidification. The present close-coupled gas atomization can only produce the mixture powders of crystal and amorphous particles.

关 键 词：铝基合金 非晶合金粉末 气雾化 快速冷凝 

分 类 号：TF123.1[冶金工程—粉末冶金]