Grain refinement is expected to be effective for improving mechanical properties of 8-type titanium alloy. However, this material is susceptible to grain growth at elevated temperature because of the high diffusivity of bcc structure. In addition, the grain boundary pinning effect by dispersed carbide particles is also hard to be used because of the small solubility of the carbide. Therefore, the grain refinement achieved by conventional melting process would be limited to around several tens micrometers. In this study, mechanical alloying (MA) technique was applied to a beta-type titanium alloy having eutectoid composition for Ti-Fe binary system. The microstructure development with annealing was investigated for the MA-treated powder, and then the bulky material with fine grained structure was obtained through consolidation of the MA-treated powder by hoi rolling in the 6 phase region.
展开▼
