摘要
Ti40阻燃钛合金热变形困难且容易发生开裂。因此,研究该合金在不失效的情况下实现预期的变形就显得非常重要。本研究采用韧性断裂准则和有限元模拟相结合的方法,对Ti40合金热变形过程进行开裂预测。通过圆柱试样不同温度和应变速率的压缩模拟试验,发现在一定的变形条件下该合金会发生纵向开裂和剪切开裂。随后的有限元模拟获得了变形试样各个区间的应力-应变分布情况及演变过程,这被用来评价6种已有的韧性断裂准则对Ti40合金高温变形的初始开裂位置及损伤值预测的准确性。研究结果表明,只有Oyane韧性断裂准则能准确地预测试验范围内所有条件的Ti40合金的初始开裂位置和临界开裂值。
Ti40 burn resistant titanium alloy shows excellent burn-resistance performance and good mechanical properties at room temperature. However, it is easy to crack because of low ductility at high temperature, especially during the ingot cogging procedure. An important concern in forming is whether or not the desired deformation can be accomplished without failure of this alloy. This paper described the utilization of ductile fracture criteria in conjunction with the finite element method for predicting failures in hot forming processes of Ti40 alloy. Cylindrical specimens under compression tests at different deformed temperatures and strain rates were experimentally investigated. It is found that the alloy exhibited longitudinal cracking and shear cracking at some conditions of deformation. Subsequently, the finite element numerical simulation of the tests obtained local stress-strain history, which was used to evaluate six previously published ductile fracture criteria for predicting the accuracies of the fracture initiation locations of Ti40 alloy in hot forming. It is proved that only Oyane et al. ductile fracture criteria can accurately predict the initial location of fracture and the damage of Ti40 alloy for all the tests performed in this work.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2006年第12期1900-1903,共4页
Rare Metal Materials and Engineering
关键词
TI40合金
韧性断裂准则
热变形
开裂预测
有限元模拟
Ti40 alloy
ductile fracture criteria
hot forming
fracture predicting
finite element simulation
