粉末冶金BeAl合金相界面裂纹微观应力场有限元分析

Finite element analysis of microcosmic stress on the phase interfacial crack of powder metallurgy Be-Al alloy

采用ANSYS有限元软件分析微观状态下粉末冶金铍铝合金裂纹沿铍铝两相界面分布时,拉伸与压缩两种情况下铍颗粒与铝基体界面处的应力场分布,定性讨论裂纹扩展延伸的机制以及对界面脱粘和屈服变形的影响。研究结果表明:裂纹形成后,对界面应力场的影响只局限在裂纹所在的微小区域内,远处的影响极小,裂纹尖端有明显的应力集中现象;在拉伸应力场中,裂尖处铝基体一侧σ1与σvon同时达到最大值,在强应力的作用下,裂纹极易沿铍铝相界面铝基体一侧失稳扩展,与实验结果基本一致;在压缩应力场中,裂尖处铝基体的σvon较之铍颗粒变化明显,屈服变形更容易在基体一侧发生。

With ANSYS software, the finite element method is used to analyze the stress field on the phase interface of the powder metallurgy Be-Al alloy, including crack between aluminum and beryllium particles. Two cases of tensile and compressive stress are calculated. Crack propagation mechanism and the effect of which on interfacial debonding and yield deformation were discussed qualitatively. The result shows that after the crack forming, stress distributions near crack along interface change obviously, tile stress focuses at the piont of crack. In the case of tensile stress, both of matrix σ1 and σvon are get to the maximum at the point of crack where interracial debonding and plastic distort occurs easily, it gives the same result as the experiment. In the case of compressive stress, σvon. near Al-matrix changes obviously compared with Be-particle at the point of crack where plastic distortion occurs easily.