选择性激光熔化成形CoCrWMo合金工艺优化及摩擦磨损性能

对选择性激光熔化成形CoCrWMo合金的工艺参数进行优化，并对最佳工艺下合金试样的摩擦磨损性能进行分析。结果表明:选择性激光熔化最佳工艺参数为激光功率280 W，扫描速度800 mm?s?1，铺粉层厚0.03 mm，扫描间距0.10 mm，扫描策略为旋转扫描法（层与层之间旋转15°）。该工艺下激光体能量密度为117 J?mm?3，试样相对密度为99.4%，上表面粗糙度（Ra）为4.98 μm，显微硬度为HV 386，抗拉强度为984 MPa，屈服强度为663 MPa，断后伸长率为12.9%。在干摩擦下，CoCrWMo合金的平均摩擦系数随施加载荷的增加呈下降趋势；受磨损过程中应变诱导马氏体转变的影响，合金平均磨损率呈现先增高后降低的变化规律，主要磨损机制为磨粒磨损和粘着磨损。

Process optimization and friction and wear properties of CoCrWMo alloys fabricated by selective laser melting

Process parameters of the CoCrWMo alloys fabricated by selective laser melting (SLM) were optimized, and the friction and wear properties of the alloy samples prepared under the optimal process parameters were analyzed. The results show that, the optimal parameters of selective laser melting are as followed: the laser power is 280 W, the scanning speed is 800 mm?s?1, the layer thickness is 0.03 mm, the scanning space is 0.10 mm, and the scanning strategy is rotation method (15° rotation between adjacent layers). The laser energy density is 117 J?mm?3, the relative density of the prepared samples is 99.4%, the top surface roughness (Ra) is 4.98 μm, the microhardness is HV 386, the tensile strength is 984 MPa, the yield strength is 663 MPa, and the elongation is 12.9%. During the dry friction, the average friction coefficient of the prepared CoCrWMo alloys decreases with the increase of the applied load, while the average wear rate increases first and then decreases under the influence of the strain-induced martensite transformation during the wear process. The main wear mechanisms are abrasive wear and adhesive wear.