预时效对TB8钛合金超塑性的影响  

Effect of Pre-aging on Superplasticity of TB8 Ti-Alloy

作　　者：董洪波[1] 姜智勇[1] 周盛武[1] 张坤 刘洪骁 DONG Hongbo;JIANG Zhiyong;ZHOU Shengwu;ZHANG Kun;LIU Hongxiao(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,Chin)

机构地区：[1]南昌航空大学航空制造工程学院,南昌330063

出　　处：《材料研究学报》2018年第7期541-546,共6页Chinese Journal of Materials Research

基　　金：航空科学基金(2015ZE56011);江西省科学计划(20151BBE50042)~~

摘　　要：研究了预时效对TB8钛合金的显微组织和超塑性的影响。结果表明,当预时效温度为520℃预时效时间为1 h时TB8钛合金的超塑性能最佳,伸长率达到362%,比未经时效的伸长率提高了165%。时效处理后在亚稳态β相晶界和晶内析出一定量的细小α相,变形时α相既能抑制基体组织的晶粒过分长大,又能在一定程度上使脱溶组织发生应变集中而破碎,使晶粒细化从而提高TB8钛合金的超塑性。在预时效温度一定的条件下,随着时效时间的延长断口组织的晶粒度先减小后增大,在时效时间约为1 h的晶粒最细小,伸长率最高。时效时间一定时,时效温度约为520℃的断口组织最为均匀,伸长率最高。The effect of pre-aging processes on superplasticity and microstructure of TB8 Ti-alloy was investigated. Results show that after pre-aging at 520 ℃ for 1 h, the superplasticity of the alloy can be the best, and the elongation is up to 362%, increased by 1.65 fold of that for the counterpart alloy; A certain amount of fine α phase precipitated at grain boundaries and in grains of the metastable β-phase after pre-aging; During the deformation process, the precipitated α phase can restrain the growth of recrystallization grains and break the dissolution phase structure, so that induce grain refinement and increase the superplasticity of TB8 alloy. In case of pre-aging at a desired pre-aging temperature, the grain size of the fractured surface decreases first and then increases with the increasing aging time, while the grain size is the smallest and the elongation is the highest by pre-aging for 1 h. In case of pre-aging for a desired period of time, the alloy aged at 520 ℃ presents the highest elongation at break with the most uniform fracture microstructure.

关 键 词：金属材料 TB8钛合金 预时效 超塑性 弥散析出 伸长率 

分 类 号：TG146[一般工业技术—材料科学与工程]