随着金属结构部件的复杂化, 广泛应用于装备制造业镍铁合金需采用激光熔覆工艺来满足复杂结构件的生产需求。针对镍铁粉末在激光熔覆中易出现缺陷问题, 本文通过对三种类型熔道(单道、横向搭接和纵向搭接)的未熔粉末、熔道倾斜等形貌缺陷进行筛选, 得出质量比m(IN625)∶m(304L)=1∶1的镍铁预混合粉末未出现缺陷的激光熔覆工艺参数; 制备出尺寸为20 mm×70 mm×70 mm的镍铁块状材料来验证该熔覆工艺参数的合理性。研究表明: 未出现缺陷的最佳激光熔覆工艺参数为: 激光功率0.8 kW, 扫描速度6 mm/s; 镍铁材料块并未出现裂纹等缺陷仅存在极少量的未熔粉末, 其组织生长方式为连续的柱状晶和等轴晶。

With the complication of metal structural components, the Ni-Fe alloy widely used in the equipment manufacturing industry needs to adopt a laser cladding process to meet the production requirements of complex structural parts. By screening the morphological defects such as unmelted powders and inclination of three types of melting channels (single channel, transverse lap and longitudinal lap), the laser cladding process parameters of Ni-Fe pre-mixed powders with mass ratio m(IN625)∶m(304L)=1∶1 were obtained. A Ni-Fe block material with a size of 20 mm×70 mm×70 mm was prepared to verify the rationality of the cladding process parameters. The research shows that the best laser power without defects is 0.8 kW, and the best scanning speed is 6 mm/s. The ferronickel block has no defects such as cracks, and only a very small amount of unmelted powder exists, and its tissue growth mode is continuous columnar crystal and equiaxed crystal.