等离子旋转电极法制备钛铝粉末性能表征

Characterization of TiAl Powders Prepared by Plasma Rotating Electrode Processing

摘要:

采用等离子束旋转电极法制备Ti-47Al-2Cr-2Nb球形粉末，粉末的平均粒径d50为85 μm, 松装密度为2.65 g/cm3。截线法测得粉末的球形度为99.6%；粉末的流动性为10.40 s/50 g；粉末的平均氧、氮含量分别为0.05%和0.004%。XRD分析表明，粉末的相组成为α2相和γ相，主相为富钛α2相；粉末经热等静压后主相为γ相，伴随少量α2相。SEM背散射照片表明，粉末颗粒的晶粒为胞状组织，晶粒平均大小约为2 μm；对不同粒径的颗粒进行EPMA分析表明，颗粒内部化学成分与预合金棒接近，颗粒表面有部分Al元素挥发，约为2at%

Abstract:

Friction stir processing (FSP) was summarized in detail. Its effect on properties of materials and the research on preparation of composites and alloys were also introduced. In addition, the problems of FSP research, the prospect and the future development were pointed out. The influencing factors and formation mechanism of the abnormal grain growth need further studies. FSP combined with melt welding can meet the requirement of welding of high strength materials such as titanium alloys. There will be a good application future for FSP to prepare nano-particles enforced metal matrix composites (MMCs) and intermetallic composites (IMCs). An inventive technique to fabricate materials with homogeneous microstructure by adopting the concepts of FSP is pivotal for its applications