氩气雾化高温合金粉末的凝固组织特征  

Microstructure characteristics of superalloy powders during rapid solidification prepared by argon atomisation

作　　者：高正江[1] 张国庆[1] 李周[1] 袁华[1] 许文勇[1] 张勇[1] 刘娜[1] 

机构地区：[1]北京航空材料研究院先进高温结构材料国防科技重点实验室,北京100095

出　　处：《粉末冶金技术》2011年第2期93-97,共5页Powder Metallurgy Technology

基　　金：北京市科技计划课题资助项目(D09080300510000);航空基金项目(2008ZF21007);国家重点基础研究发展计划资助项目(2010CB631205)

摘　　要：为深入了解高温合金粉末粒度细化对粉末涡轮盘性能的影响,对不同尺寸氩气雾化高温合金粉末的凝固组织特点进行了分析和研究。结果表明：AA粉表面和内部凝固组织主要为树枝晶和胞状晶组织,晶界和枝晶间分布少量富Ti、Nb的MC＇型碳化物。随着粉末尺寸的减小,冷却速率增大,组织从树枝晶向胞状晶转变,基体γ相晶面间距和点阵常数增加。小尺寸AA粉因溶质固溶极限增大和晶粒细化,显微偏析分散度大大提高,具有优良的显微组织和化学均匀性。AA粉γ相的点阵常数约为0.359 10~0.359 36nm。The microstructure characteristics of superalloy powders prepared by argon atomisation have been investigated.The results show that the solidification microstructures of surface and interior of particles are dentrite and cellular strctures.With decreasing of the particle size,the microstructures of particles change from dentrite in major to cellular strctures.MC-type carbides riched with Ti and Nb are the major precipitate phase located in grain boundary and interdentrite.Having a higher cooling rate,a smaller droplet has larger interplanar distance and lattice constant of γ-phase,and smaller dentrite microsegregation.So small powders with large solid solubility limit and small crystal grains have good microstructures and chemistry eveness.The lattice constant of AA powders is about 0.359 10~0.359 36nm.

关 键 词：高温合金粉末 凝固组织 氩气雾化 快速凝固 

分 类 号：TF125.4[冶金工程—粉末冶金]