电冶熔铸WC／钢复合材料表面激光重熔工艺

Laser surface remelting of WC/steel composites fabricated by electro-slag melting and casting

采取不同激光工艺重熔经过热处理的电冶熔铸WC/钢复合材料,分析了材料表面组织形貌和结构的变化。结果表明,为增加材料对激光的吸收率,重熔前需对试样作预处理,并采用高的激光功率和低的扫描速度。激光功率可以显著增加激光影响区的厚度,而扫描速度的影响相对较小。激光重熔电冶熔铸WC/钢复合材料的强化机制为细晶强化和沉淀强化。由此选用激光功率为2.0 kW,扫描速度为600或800 mm/min较为理想。

WC/steel composites fabricated by electro-slag melting and casting were remehed by laser with various processing parameters after pre-original heat treatment. The variation of surface morphology and mierostmcture of the composites was analyzed. The results show that it is necessary to have a pre-treatment before the laser remehing in order to increase the absorptive rate of laser into the materials. High laser power and low scanning rate should be applied. The laser power can increase depth of laser affecting zone, while the effect of scanning rate is comparative lower. Strengthe- ning mechanism of laser surface remelting the WC/steel composites is the fined crystal and precipitation, therefore the proper laser melting processing parameters could be selected as 2.0kW of laser power and 600 ram/rain or 800 mm/min of scanning rate .