工艺参数对激光选区熔化成形纯镍表面质量及致密化行为的影响

Effects of selective laser melting parameters on surface quality and densification behaviours of pure nickel

研究激光功率和扫描速度对激光选区熔化(SLM)成形纯镍的熔覆道特征、致密化行为和表面粗糙度的影响规律。结果表明,在一定范围内提升激光功率并降低扫描速度,可成形出连续、规则、光滑的熔覆道,这有助于抑制SLM成形过程中孔隙、球化等缺陷的形成。当扫描速度为900 mm/s、激光功率为255~275 W时可获得最佳成形工艺窗口,此时,试样相对密度为99.16%,抗拉强度为(360±2.747)MPa,上表面和侧表面的粗糙度分别为(2.88±2.23)μm和(14.98±0.69)μm。

The effects of laser power and scanning speed on the forming characteristic of scanning tracks,densification behaviours and surface roughness of pure nickel fabricated with selective laser melting(SLM)were studied.The results indicate that the scanning tracks showed continuous,regular and flat surface with increasing laser power and decreasing scanning speed in a specific range,which could avoid the defects(like holes and balling structures)forming in SLM processing.The optimal process window was identified as the scanning speed of 900 mm/s and the laser power of 255−275 W by comparing the surface qualities and densification behaviours.With the suitable processing parameters,the relative density could achieve 99.16%,the tensile strength was(359.49±2.74)MPa,and the roughnesses of the top and side surfaces were(12.88±2.23)and(14.98±0.69)μm,respectively.