热处理对β相区形变热处理TC21钛合金锻件组织性能的影响

研究了不同热处理制度对β相区形变热处理的TC21钛合金锻件组织及性能的影响.试验结果表明:不同热处理制度对TC21钛合金等温锻件的组织性能有显著的影响.仅经形变热处理后的锻件显微组织不均匀,强度可高达1,400MPa,但塑性较低；经强韧化处理后的锻件显微组织为:层次感强、编织度较好的网篮组织,在获得较高强度的同时,塑性下降不多；经淬火时效处理后的锻件显微组织中的α相编织度较好,锻件强度、塑性获得较佳匹配；等温退火后锻件的显微组织为:α相尺寸合适、编织度较佳的网篮组织,但强度有所下降,塑性未有提高.淬火时效处理为推荐的较佳热处理制度.

Effect of Heat Treatment on Microstructure and Tensile Properties of TC21 Titanium Alloy after Thermo-mechanical Processing in β Field

The effect of heat treatment on microstructure and tension properties at RT of TC21 titanium alloy isothermal forged was investigated.The results indicate that the multiple thermo-mechanical heat treatment can greatly strengthen the isothermally forging,while the plasticity descending is caused by the precipitation of the elongated and blocky alpha phase along the primary grain boundary.The effect of dispersion strengthen can be enhanced by means of toughening-strengthening or quench aging heat treatment,while the plasticity descending is caused by the coarsen interface α phase.The nice knitted basket microstructure can be got by isothermal anneal,but the coarsen interface α phase is still existed,also the ductility is low.Comparatively,quench aging treatment can guarantee the basket microstructure obtained and relatively eliminate the beta-brittleness.So,the quench aging treatment of 900℃/1h,WQ +590℃/4h,AC is recommended.