TB8钛合金超塑性拉伸变形流变行为与本构方程  

Superplastic Tensile Deformation Behavior and Constitutive Equation of TB8 Titanium Alloy

作　　者：王明主 董洪波[1] 邹忠波[1] 王鑫[1] 

机构地区：[1]南昌航空大学航空制造工程学院

出　　处：《特种铸造及有色合金》2016年第1期103-106,共4页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51164029)

摘　　要：在电子万能拉伸试验机上对TB8钛合金进行了恒应变速率超塑性拉伸试验(变形温度为720~880℃,应变速率为0.000 1~0.01s^(-1)),研究了拉伸流变行为,计算了超塑性拉伸变形激活能和相应的应力指数,建立了TB8钛合金应力-应变本构模型。结果表明,在同一应变速率下,流变应力随变形温度的增加而减少,同一变形温度下,流变应力随应变速率的增加而增加。在变形温度为840℃,应变速率为10^(-4) s^(-1),合金的伸长率最大,为356%;超塑性拉伸变形激活能和应力指数分别为251.25kJ/mol、2.389 5。Superplastic tensile test of TB8 alloy was carried out with constant strain rate in the electronic universal tensile testing machine at 760~880 ℃ and strain rate of 0.000 1~0.01s^-1.Flow stress behavior was analyzed,and the superplastic tensile deformation activation energy and corresponding stress exponent were calculated.Stress-strain constitutive model of the TB8 titanium alloy was established.The results show that the flow stress is decreased with the increase of deformation temperature at a constant strain rate,while it is increased with the increase of strain rate at a constant deformation temperature.The maximum elongation of 356% can be obtained with the deformation at 840 ℃ and the strain rate at 10^-4 s^-1.The superplastic deformation activation energy and the corresponding stress exponent are 251.25kJ/mol and 2.389 5,respectively.

关 键 词：TB8钛合金 超塑性变形 流变应力 本构方程 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG135.3[金属学及工艺—金属材料]