中文摘要：

采用金相和能谱方法对Ti、Al箔的固相扩散反应行为进行了研究,建立了TiAl3相层厚度生长的计算公式.并在此基础上,探讨了球磨Ti/Al复合粉的两步固相烧结工艺.研究表明：两步固相烧结法可有效抑制烧结引起的粉末体变形,获得具有典型显微组织的致密烧结材料;尽管延长低温预烧时间可获得由TiAl与Ti3Al组成的热稳定性较好的组织,但组织致密度偏低,为了获得高致密的TiAl合金,仍需后续高温烧结.实验还表明,高能球磨促进了TiAl基合金组织细化,且球磨时间越长烧结组织晶粒越细小;双态组织中的层片组织含量随球磨时间延长而增加,但长时间球磨由于非晶化的出现又会引起层片组织含量下降.

英文摘要：

The solid-state diffusion reaction behavior between Ti and Al foils was studied by using optical microscopy and energy spectrometer, and an equation describing the growth of TiAl3 phase layer was deduced. Moreover, a two-step solid-state sintering process of milled Ti/Al composite powders was investigated. The results indicate that （1） the proposed two-step solid-state sintering effectively avoids the deformation of powders during the sintering process and helps to obtain dense TiAl alloys with typical microstructure; （2） in order to obtain highly dense TiAl alloy, a sintering at elevated temperature after the presintering for a prolonged time at low temperature is necessary because the presintering only helps to form thermostable microstructure of TiAl and Ti3Al and the relative density is still low; （3） the high-energy ball milling leads to fine TiAl microstructure, the longer the milling time, the finer the sintered alloy; and （4） with the increase in milling time, the content Of lamella colonies in the dual-phase sinter first increases but then decreases due to non-crystallization.