变形温度对TC11合金低应变速率下的变形行为及组织的影响  

Effect of Temperature on Deformation Behavior and Microstructures at Low Strain Rate of Titanium Alloy TC11

作　　者：王克鲁[1] 鲁世强[1] 李鑫[1] 董显娟[1] 杨化娟[1] 

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063

出　　处：《稀有金属》2009年第2期142-146,共5页Chinese Journal of Rare Metals

基　　金：江西省自然科学基金(2007GQC1575);江西省教育厅科技项目(GJJ08203)资助

摘　　要：采用THERMECMASTOR-Z热模拟试验机研究了TC11钛合金在变形温度780—1080℃，应变速率0．001～1s^-1范围的热变形行为，并采用金相显微镜研究了变形温度对TC11钛合金组织的影响，主要研究结果如下：变形温度对TC11钛合金的流动应力有显著影响，在较高温度或较低应变速率时，变形呈稳态流动特征；在较低温度或较高应变速率时，变形呈流变软化特征。在8单相区，当应变速率为1s^-1时，组织主要为拉长的B晶粒和少量的动态再结晶晶粒；当应变速率为0．01～0．1s^-1时，变形机制主要为动态再结晶；当应变速率在0．001s^-1附近时，变形机制为动态回复。在（d＋B）两相区，变形温度870～960℃，应变速率0．001s。附近时，变形机制为超塑性。Abstract： The hot deformation behavior of titanium alloy TCll with an equiaxed （ α ＋ β） starting microstructure was studied in the temperature range of 780- 1080℃ and strain rate range of 0. 001 - 1 s^-1 with a Thermecmaster-Z simulator. In addition, the effect of temperature on microstructure was observed using optical microscope. The results showed that the temperature affected the flow stress and microstructure of titanium alloy TC11 obviously. The steady state flow characteristics existed during hot deformation of titanium alloy TC11 at higher temperature or lower strain rates. The flow softening characteristics existed at low-er temperature or higher stain rates. Microstructure examinations showed that in the β phase region, fine grains which along elongated β grain boundaries were observed at strain rate 1 s^-1 the operative deformation mechanism was partly dynamic recrystallization. Full dynamic recrystallization of β grains occurred in the strain rates range of 0. 01 -0.1 s^-1, and dynamic recovery of β grains occurred at strain rate of 0. 001 s^-1. In the α ＋ β phase region, the optimum thermomechanical parameters were in the temperature range of 870-960 ℃ and strain rate of 0. 001 s^-1 with the operative deformation mechanism of superplasticity.

关 键 词：TC11钛合金 变形温度 变形行为 微观组织 

分 类 号：TG146.2[一般工业技术—材料科学与工程]