高压强脉冲电流对金属裂纹的止裂效果

Effect of High Voltage Pulse Current on Crack Arrest

如何产生高强度脉冲电流是应用电磁热效应遏制金属裂纹扩展的一个关键问题。介绍了高压脉冲放电装置的工作原理,从理论、数值模拟、实验三个方面,通过对不同尺寸的裂纹试件导入强脉冲电流而产生的电磁热效应的止裂效果进行了分析和研究,研究结果表明:强脉冲电流产生的电磁热效应,能够使裂纹尖端处熔化形成微小的焊口,遏制了裂纹的扩展。试件的通流尺寸、电阻率、导入电流密度是影响裂纹尖端温度场和温度梯度场的主要因素。

Generation of powerful pulse current is a key problem for crack arrest by electromagnetic heat effect. The principle of high voltage pulse discharging is introduced. The theoretical analysis, numerical simulation and experiment study were carried out for crack arrest by electromagnetic heat effect in metal samples of different size. The experiment showed that the metal at tip of crack was melted and joint was formed to arrest crack. The size of current path, resistivity, power density are main factors that effect the temperature field and temperature gradient field at crack tip.