7050高强铝合金断裂韧性及其影响因素研究

Fracture Toughness and Influencing Factor for 7050 High Strength Aluminum Alloy

摘要:

针对国产7050高强铝合金紧凑拉伸(compact tension, CT)试验中出现宏观开裂角过大、试验成功率偏低、断裂韧性不达标的问题，基于CT试验结果，提出了改进工艺对坯料进行锻造，并与传统制坯方法进行对比分析。结果显示，改进工艺降低了7050高强铝合金的各向异性，提高了其断裂韧性水平以及CT试验成功率；同时发现，造成CT试验成功率低的因素包括材料各向异性和试样预制裂纹长度两个方面，降低各向异性和适度提高预制裂纹长度，可有效降低试样宏观开裂角，并给出了参考的预制裂纹长度的范围

Abstract:

To solve the problems in the compact tensile tests of the 7050 high strength aluminum alloy, such as oversized crack angle, low mission success rate and substandard of the fracture toughness, the comparisons were conducted between the traditional process and the modified process. The result shows that the modified process enhances the level of the fracture toughness and the mission success rate. Besides, the reasons of the low mission success rate are shown at two main aspects which are the anisotropy and the length of the precrack. Reducing the level of the anisotropy or increasing the length of the precrack can effectively decrease the crack angle; meanwhile, the reference range of the precrack length is given for 7050 high strength aluminum alloy