TC18钛合金铸锭组织特征及热变形行为

Microstructure Characteristics and Hot Deformation Behavior of TC18 Titanium Alloy Ingots

文章主要介绍了TC18钛合金大型铸锭的组织特征,利用热模拟试验机对铸态组织开展了热压缩试验,研究了不同温度和应变速率下的热变形行为,分析了应力应变曲线,计算了表观变形激活能、应变速率敏感性指数和应变硬化指数等表征指标。结果表明:TC18钛合金铸锭头部和中部低倍组织相比,中部铸态组织出现了大晶粒区域;TC18钛合金铸态组织的表观变形热激活能平均值为189.81kJ·mol^(-1)。当应变为0.6时,应变速率敏感性指数在应变速率1s^(-1)时,随变形温度的增加,m值先增加后降低。

In this paper,the microstructure characteristics of large ingots of TC18 titanium alloy are introduced.The hot compression test of as-cast structure is carried out by thermal simulation testing machine,the thermal deformation behavior at different temperature and strain rate is studied,the stress-strain curve is analyzed,and the apparent deformation activation energy,strain rate sensitivity index and strain hardening index are calculated.The results show that there is a large grain area in the as-cast structure of TC18 titanium alloy compared with the as-cast structure in the middle part of the ingot,and the average apparent thermal activation energy of as-cast structure of TC18 titanium alloy is 189.81kJ·mol^(-1).When the strain is 0.6,the strain rate sensitivity index increases at first and then decreases with the increase of deformation temperature at strain rate 1s^(-1).