为研究电磁场对激光再制造V型槽中孔隙调控的影响,在激光再制造过程中同时耦合稳态的磁场与电场,以产生定向洛伦兹力;通过激光再制造实验研究了激光功率与电磁场参数对V型槽内孔隙率的调控规律,实验结果显示:当激光功率小于1400 W时,V型槽底部界面结合处易产生熔合不良现象,并且修复区内存在大量气孔;随着磁感应强度增大,V型槽底部熔合不良现象得到了有效调控,修复区内的孔隙率逐渐降低;当磁感应强度为1200 mT时,修复区的孔隙率降至0.006%,修复区内几乎无气孔与熔合不良缺陷。稳态磁场与稳态电场所提供的向下的洛伦兹力驱使金属熔体向下填充,并使气泡受电磁挤压力的作用而加速逸出,最终获得了致密的修复区。

In this study, the steady magnetic and electric fields are coupled in the laser remanufacturing process to generate the directional Lorentz force to study the influence of electromagnetic field on the pore regulation in the laser remanufactured V-groove. The influences of the laser power and electromagnetic field parameters on the porosity of narrow V-grooves are studied using laser remanufacturing experiments. Results show that when the laser power is less than 1400 W, the boundaries between the original part and the added material are prone to poor fusion, and a large number of pores exist in the repaired area. With the increase of the magnetic field intensity, the poor fusion at the bottom of the V-groove is controlled, and the porosity in the repair area gradually decreases. When the magnetic induction is increased to 1200 mT, the porosity of the repair area decreases to 0.006%, and almost no porosity and poor fusion defects appear in the repair area. The downward Lorentz force provided by steady magnetic and electrical fields drives the metal melt to fill downward and accelerate the escape of the bubbles by the eletromagnetic squeezing force, finally obtaining a dense repair area.