PCA-TOPSIS法在激光熔覆工艺参数优化中的应用

Optimization of Process Parameters for Laser Cladding Based on PCA-TOPSIS Method

为了改善H13钢抗疲劳磨损性能,利用4kW光纤激光器在H13钢表面激光熔覆Ni60A合金涂层。利用正交试验分析各工艺参数对熔池尺寸的影响。运用光学显微镜和扫描电镜分析涂层的显微组织形貌,通过显微硬度计测试涂层截面的显微硬度分布。依据单道熔覆层的熔池尺寸,采用PCA-TOPSIS法作为评价方法。以熔宽最大、熔深和熔高最小为优化目标,得出最佳工艺参数为激光功率(P)2.2kW,扫描速度(V)20mm/s,送粉率(F)26.42g/min。该工艺参数下的熔覆层与基体呈现良好的冶金结合、无气孔裂纹等缺陷,熔覆层截面显微硬度平均高达800HV,是基体的(3~4)倍。

In order to improve the wear resistance of H13 steel,laser clad Ni60A alloy coating was fabricated on the surface of H13 steel by using a 4 kW fiber laser. Effects of parameters on size of melted pool were researched by orthogonal experiment.The microstructure was investigated OM and SEM. The microhardness distribution of coating was tested by using microhardness tester. According to the size of the single channel cladding,the PCA-TOPSIS method was used as the evaluation method to optimize the target with the maximum width,minmum depth and height of the cladding. Optimization of process parameters were as follows:laser power(P)2.2 kW,scanning speed(V)0.02 m/s,powder feeding rate(F)26.42 g/min. Under the laser cladding parameters,good metallurgical bonding and no porosity defects such as cracks were obtained. The microhardness of the cladding layer exceeded 800 HV,which was 3 to 4 times higher than that of the substrate.