置氢Ti-55钛合金变形本构方程及高温增塑机理研究  

Constitutive equation and high temperature plasticizing mechanism of hydrogenated Ti-55 titanium alloy

作　　者：纪博宇 李细锋[1] 李剑飞 JI Bo-yu;LI Xi-feng;LI Jian-fei(Institute of Forming Technology and Equipment, Shanghai Jiao Tong University, Shanghai 200030, China;AVIC Chengdu Aircraft Industry, （Group） Co. , Ltd. , Chengdu 610091, China)

机构地区：[1]上海交通大学塑性成形技术与装备研究院,上海200030 [2]航空工业成都飞机工业(集团)有限责任公司,四川成都610091

出　　处：《塑性工程学报》2018年第1期180-186,共7页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(51475295)

摘　　要：钛合金的热氢工艺能够有效改善合金的热加工性能,进一步优化钛合金超塑变形条件。以Ti-55钛合金为研究对象,通过高温拉伸、金相观察等方法,建立了原始合金及置氢合金的高温变形本构方程,研究了原始合金和置氢合金的超塑变形行为以及变形后的微观组织,得出了合金氢致高温增塑的微观机理。研究发现,置氢能够降低合金的热变形激活能,置氢0.1 wt%合金相较于原始合金和置氢0.3 wt%合金具有更高的应变速率敏感性指数,达到了0.516;置氢0.1 wt%合金在变形过程中β相含量稳定,且在α相晶界上保持均匀分布,协调变形能力较强,能够抑制颈缩的形成,有利于提高伸长率,改善材料力学性能。Thermo-hydrogen processing can improve the hot workability of titanium alloys and further optimize the superplastic deformation condition. Taking the Ti-55 titanium alloy as object,the constitutive equations were established and the superplastic deformation behavior and deformed microstructure were studied for as-received and hydrogenated alloys by high temperature tensile tests and optical microscopy.The microscopic mechanism of hydrogen induced high temperature plasticizing was obtained. The results show that thermal deformation activation energy is reduced by hydrogenating. The strain rate sensitivity exponent of 0. 1 wt% hydrogenated alloy reaches 0. 516,which is higher than that of as-received and 0. 3 wt% hydrogenated alloys. The β phase in 0. 1 wt% hydrogenated alloy is evenly distributed on αphase grain boundary with stable content during superplastic deformation,which improves compatible deformation capability to suppress local necking formation,increase the elongation and improve the mechanical properties of the materials.

关 键 词：Ti-55钛合金 超塑变形 置氢 高温增塑 

分 类 号：TG146.2[一般工业技术—材料科学与工程]