使用激光诱导微弧放电的方法对45#钢进行了表面强化。通过实验对比了高压诱导放电(HVGD)和激光诱导放电(LGD)两种表面强化方法。发现激光诱导放电使电极间隙的击穿电压降低了一个数量级, 同时放电点和激光焦点重合, 实现了对放电点位置的控制。在两种诱导放电过程中放电点的膨胀速度基本相同, 但是受到初始放电点大小的影响, 激光诱导放电点直径大于高压诱导放电点。在两种诱导放电过程中强化深度都存在最大值, 约为180 μm。放电点的强化层由熔凝层和相变硬化层组成, 其中熔凝层的硬度最高达到800 HV。

This paper studies the method of surface strengthening to 45 steel by laser-guided micro discharge, and compared the method by laser-guided discharge (LGD) with the method by high voltage-guided discharge(HVGD). It was found that the break voltage of electrode gap was decreased a grade, and the discharge pit was completely lapped over the laser focus by laser-guiding. The expanding speed of discharge pit was almost same in two kinds of discharge processing. Because of the effect of the diameter of initial discharge pit, the diameter of laser-guided discharge pit was always bigger than the diameter of high voltage-guided discharge pit. The most thickness of layer-strengthened in two kinds of discharge processing were almost same about 180 μm. The strengthened layer of discharge pit included the melted layer and hardening layer. The most hardness of strengthened layer was about 800 HV.