钛合金热变形过程中裂纹缺陷的预测

Fracture Prediction during Hot Deformation Process of a Titanium Alloy

摘要:

基于连续损伤力学（CDM）理论，同时考虑包括温度和应变速率在内的变形历史影响，建立TC11钛合金热变形过程中的损伤演化方程，提出宏观裂纹预测的断裂准则，并采用高温拉伸试验确定方程和准则中的参数。将提出的方法用于TC11合金热压缩变形过程中的数值模拟，模拟结果同实验结果的对比表明该方法可以很好地预测合金在热变形过程中裂纹的起裂和裂纹的扩展行为。

Abstract:

Based on the continuum damage mechanics (CDM) theory, a fracture prediction method for hot deformation was proposed by considering the influence of deformation history including both temperatures and strain rates effect. According to the proposed method, the fracture criterion was established for crack predication of TC11 alloy with lamellar structure during hot deformation and the materials parameters were determined using high temperature uniaxial tensile tests; the fracture criterion was then applied to simulation of isothermal compression process, and the predicted results show good agreement with experimental observations in both crack initiation and development.