摘要
裂纹对材料或结构的寿命会产生很大危害,但裂纹的控制和修复技术却远未达到预期.本文针对含预制0.8 mm深长直裂纹的2A12航空铝合金进行搅拌摩擦修复试验,利用金相显微镜、扫描电镜对其修复区微观组织演变和热塑性金属流动进行了观察分析,建立了搅拌摩擦修复物理模型.具有细小等轴晶的修复区形成过程为:裂纹附近金属材料首先经过热影响区,到热塑性金属流动区,最后通过动态金属再结晶,生成内部细小等晶轴修复区.这些材料的晶体则历经晶粒长大、破碎、再结晶,从而修复裂纹.
Cracks will do great harm to engineering materials and structures,but the crack controlling and repairing methods are still far from expected. Aviation aluminum alloy 2A12 containing prefabricated 0. 8 mm deep horizontal cracks were repaired by friction stir method. The microstructure evolution and thermoplastic metal flow behavior of the healing zone were observed and analyzed by metallurgical microscopy and scanning electron microscopy. A physical model named friction stir crack repairing process was established. Materials near the crack experienced heat affected zone,thermoplastic metal flowing zone and dynamic recrystallization zone successively,and the healing zone was finally formed with fine equiaxed crystal grains. The corresponding materials near the crack interface experienced a continuous process of the grain growing up-deformation-crushing — recrystallization,and finally the cracks were repaired successfully.
作者
王桂荣
王磊
任俊刚
回丽
张占昌
WANG Guirong;WANG Lei;REN Jungang;HUI Li;ZHANG Zhanchang(School of Eleetromechanical Engineering, Shanghai Donghai Vocational and Technical College, Shanghai 200241, China;School of Electromechanical Engineering, Shenyang Aerospace University, Shenyang 110136, China;School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004 ,China)
出处
《昆明理工大学学报（自然科学版）》
CAS
北大核心
2018年第3期19-24,共6页
Journal of Kunming University of Science and Technology(Natural Science)
基金
国家自然科学基金青年科学基金项目(51405309
51775355)
关键词
搅拌摩擦
裂纹修复
裂纹修复的物理模型
动态再结晶
friction stirs
crack repair
physical model crack repair
dynamic recrystallization
