(湖南大学 材料科学与工程学院，长沙 410082)
摘 要: 研究TiH2粉末的高能行星球磨规律，然后使用制备出的球磨粉末开展压制-真空烧结，评价烧结样品的显微组织特征。结果表明，TiH2粉末的高能球磨可划分为3个基本阶段：球磨初期粉末粒度迅速细化；球磨中期粉末粒度逐步趋向最小极限尺寸，同时粉末粒径的均匀性和分布集中程度明显改善；在球磨的后期，粉末粒径又会发生粗化现象。因此，TiH2粉末的高能行星球磨存在一组最佳的工艺参数。高能球磨会改变TiH2粉末的脱氢特征温度，且粉体的D50越小，特征温度下降幅度越大，与原料粉末相比，最大差值达83 ℃。对烧结样品的显微组织分析显示，通过由球磨TiH2粉末所获得的烧结钛合金的晶粒度得到了显著地细化；当采用优化的工艺开展球磨TiH2粉末制备时，通过压制和真空烧结可获得平均晶粒度在5 μm以下的超细晶钛。
关键字: TiH2；行星球磨；粉末粒度；显微组织；晶粒度
（College of Materials Science and Engineering, Hunan University, Changsha 410082, China）
Abstract:The planetary milling of TiH2 powders was systematically investigated, and then the sintered samples fabricated by pressing and sintering in vacuum of the milled powders was inspected to reveal the influence of high-energy milling on their microstructures. The results indicate that planetary milling of TiH2 powders can be divided into three stages. At the initial milling, the size of the powders is rapidly reduced. At the middle milling stage the particle size gradually reaches the minimum, and the scope of size distribution also become more and narrower at the same time as milling goes on. And the size of the powders is raised at the final milling stage. It is also discovered that dehydrogenation temperatures of milled TiH2 powders decrease in comparison with those of raw powders, and the finer the D50, the lower the temperatures. The maximum temperature difference becomes 83 ℃. Optical analysis shows that the grain size of the sintered titanium samples is obviously fined after milling raw powders. With the optimized milling treatment, the sintered titanium becomes ultrafine grain with size totally less than 5 μm by pressing and sintering in vacuum.
Key words: TiH2; planetary milling; particle size; microstructure; grain size
