论文部分内容阅读
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.
The experimental and theoretical studies on the preparation of Al-based alloy powders by the close-coupled gas atomization have been carried out.The surface morphology, microstructure and structure of the powders were analyzed by means of X-ray diffractometer, differential thermal analyzer, scanning electron microscope and transmission electron microscope , The critical cooling rate of amorphization of Al-based alloy and the corresponding powder size were determined according to the breaking mode and cooling behavior of the droplet during the gas atomization process.The results showed that there were some amorphous powder and amorphous powder in the gas atomized powder The grain size of the Al-based alloy is about 106K · s-1. The melting and cooling of the melt in the atomization process are two mutually coupled (rapid cooling) processes (greater than 104K). s-1) greatly hinders the full atomization of the melt, while the droplet breaking mode has a significant effect on the cooling behavior of the present tightly coupled gas atomization technology can only produce amorphous / crystalline mixed Al group Alloy powder.