为研究18Ni300模具钢选区激光熔化成形过程中多目标最优工艺问题,设计了以激光功率、扫描速度、扫描间距、铺粉厚度为工艺参数,以致密度、硬度、耐磨性为响应目标的响应面中心组合设计实验。结合灰色关联分析得到多目标的综合灰色关联度,通过分析实验的灰色关联度得到了拟合度达78.50%的回归预测模型,以及针对三个响应目标的最优工艺参数,分别为激光功率250 W,扫描速度850 mm/s,扫描间距0.05 mm,铺粉厚度0.02 mm,此工艺参数理想的灰色关联度可达0.9312;在最优工艺参数下得到了相对密度为99.5%、硬度为41.5 HRC、磨损体积为192000 μm 3、灰色关联度为0.8895的验证样件,该样件符合预期结果,说明优化方法切实可行。

This study design a surface response central composite design experiment to research the multiple targets technology optimization problem during the selective laser melting forming 18Ni300 die steel. Here, laser power, scanning speed, hatching distance, and powder coating thickness are considered as technology parameters and relative density, hardness, and wear resistance are considered as response targets. Combining with gray relational analysis to obtain the gray relational grade (GRG) of multiple targets and by analyzing the GRG value, we developed a regression model whose fitting value could reach 78.50%. Simultaneously, a group of optimized technology parameters, such as laser power of 250 W, scanning speed of 850 mm/s, hatching distance of 0.05 mm, and powder coating thickness of 0.02 mm, could be obtained. With the same arithmetic, optimized technology parameters group could get a better GRG value of 0.9312. Subsequent to performing confirmatory experiments, we obtained the sample with a relative density of 99.5%, hardness of 41.5 HRC, wear volume of 192000 μm ³, and GRG of 0.8895. The result is consistent with the prediction and the optimization method is reliable.