摘要
采用热模拟压缩试验与有限元分析相结合的方法，对Ti40阻燃合金在温度900～1100℃、应变速率0．01-10s^-1范围内的热变形开裂问题进行了研究。发现Ti40合金的临界开裂变形量目随变形温度和应变速率的变化规律可用一个单变量Zener-Hollomon因子表示，并与1nZ成线性关系。在此基础上，运用冷成形过程广泛采用的Oyane准则对Ti40合金的开裂行为进行了分析。发现Oyane准则能够准确地预测Ti40合金压缩过程中开裂发生在最大臌肚的外表面处，且开裂的临界Cf值随变形温度升高和应变速率降低而增加，与1nZ也成线性关系。由此得到的Ti40合金高温变形下的开裂准则能够更直观地反映变形参数与开裂的临界Cf值之间的关系，为成功地预测Ti40合金高温变形时的开裂提供了有力的依据。
By means of simulative hot compression tests in conjunction with the finite element method, the fracture criterion of burn resistant titanium alloy Ti40 at the temperature range of 900-1100 ℃ and strain rate range of 0.01-10s^-1duringt hot forming was investigated. The results show that a single variable Zener-Hollomon parameter that accounts for a combined effect of temperature and strain rate, was introduced to indicate the critical fracture strain ef, and the relation between them was a linear. The fracture behavior of Ti40 alloy was analyzed by Oyane criteria which is used extensively for cold forming. It was found that Oyane criteria can accurately predict the location of crack initiation of Ti40 alloy during hot compression tests. Meanwhile, the fracture critical value of Cf increased with the increasing of temperatures and decreasing of strain rates, and a linear relation with lnZ is also found. The fracture criteria of Ti40 alloy obtained at high temperature deformation can reflect the relationship between deformation parameter and the fracture critical value of Cf much more clearly, it should be a powerful tool to predict the fracture of Ti40 alloy at hot forming successfully.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2008年第4期604-608,共5页
Rare Metal Materials and Engineering
基金
国家“973”计划(2007CB613807)
国家“十五”科技攻关项目(MKPT-01-101)
