2A12铝合金试件中空间斜裂纹在线止裂及性能分析

 选择带有空间斜裂纹的2A12铝合金试件进行了拉伸载荷作用下电磁热在线止裂研究。采用数值分析方法确定了止裂工艺参数，并求得了放电后试件内的温度场及热应力场；通过自制加载装置，应用ZL-2超强脉冲电流放电装置完成了空间裂纹在线止裂试验；对止裂前后的铝合金试件进行了微观组织分析和宏观力学性能测试。研究表明：脉冲放电瞬时，裂纹尖端熔化、钝化，并形成了高压应力区，提高了裂纹的扩展功，在一定的拉伸载荷下，试件也不会开裂，达到了裂纹在线止裂的目的。

On-line Crack Prevention and Performance Analysis of Aluminum Alloy 2A12 Specimen with Oblique Crack

A study of crack prevention under tensile load is performed on an aluminum alloy 2A12 specimen with an oblique spatial crack by using electromagnetic heating on-line.Crack preventing technical parameters are determined by numerical analysis,and the temperature field and thermal stress field are obtained after discharge.By using a self-prepared homemade loading device and the super pulse current generating equipment of ZL-2,the spatial crack preventing experiment is carried out by electromagnetic heating on-line.Microstructure analysis and macroscopical mechanical property test are performed on the aluminum alloy specimen pre-and post prevention.Results show that at the time of pulse current discharging,the crack tip melts,dulls and forms a compressed stress area,which increases the propagation work of the crack.The crack will not propagate even with a certain amount of tensile load;thus the formation of the main crack source will be prevented.