一种γ-TiAl合金微裂纹成核及断裂模型

Microcrack Nucleation and Fracture Model for γ-TiAl Alloy

结合宏观断裂理论和微观位错塞积理论,研究了γ-TiAl合金的拉伸断裂行为。应用一种位错分布模型对γ-TiAl合金微裂纹成核和开裂机制进行定量分析,应用应变能密度理论的S准则,研究建立γ-TiAl合金的失稳开裂判据。试验结果表明,采用位错塞积模型和S准则对TiAl合金的拉伸断裂行为进行判定是有效的。

Basing on the macro fracture theory and micro dislocation pile-up theory,investigating the tensile fracture behavior of γ-TiAl alloy was implemented,including having dislocation distribution model adopted to quantitatively analyze γ-TiAl alloy’s microcrack nucleation and crack mechanism,and having S criterion of strain energy density theory employed to establish γ-TiAl alloy’s instability crack criterion. The experimental results show that,adopting both S criterion and dislocation distribution model to determine tensile fracture behavior of γ-TiAl alloy is effective.