冷却速度对气雾化非平衡Al-27%Si合金粉末组织形貌特征的影响  

Influences of Cooling Rate on Microstructures and Morphologies of Non-equilibrium Al-27% Si Alloy Powders by Gas Atomization

作　　者：解立川[1] 彭超群[1] 王日初[1] 蔡志勇[1] 刘文水[1] 马如龙[1] 

机构地区：[1]中南大学,湖南长沙410083

出　　处：《稀有金属材料与工程》2015年第4期1006-1011,共6页Rare Metal Materials and Engineering

基　　金：国家军品配套项目(JPPT-125-GH-039)

摘　　要：采用快速凝固气体雾化技术制备Al-27%Si合金粉末,利用对流传热原理计算合金粉末的冷却速度,采用扫描电镜（SEM）观察分析不同粒度合金粉末的形貌。结果表明：快速凝固气体雾化的冷却速度介于103-106 K/s之间,对合金粉末形貌组织有较大影响。该合金粉末中细小初晶Si相和共晶Si相均匀弥散分布在α-Al基体中,且Si颗粒尺寸随粉末尺寸减小而减小。通过测定合金粉末二次枝晶间距,结合冷却速度与二次枝晶间距之间的经验公式,能较好地预测实验结果。The A1-27%Si alloy powders were manufactured by a rapid solidification gas atomization technique. The cooling rate of alloy powders was calculated based on the convection heat transfer principle. The morphologies and microstructures of alloy powders were investigated by scanning electron microscopy （SEM）. The results show that A1-27%Si alloy powders fabricated by the rapid solidification and gas atomization technology have a high cooling rate （103-106 K/s）, which has a significant effect on the morphology and microstructure of the alloy powders. The primary crystal and eutectic silicon phases distributed in the a-A1 substrate are in a dispersive state, and the silicon particle size is decreased with the size of the powder decreasing. The theoretical equation, which is deduced from the combination of the calculation results of the secondary dendrite arm spacing and the empirical formula, can soundly predict sundry the experiment results to a certain extent.

关 键 词：快速凝固 Al-27%Si合金 冷却速度 组织 形貌 

分 类 号：TG146.21[一般工业技术—材料科学与工程]