SLM激光单道扫描成型纯钨薄壁件的研究

Research on Pure Tungsten Thin Wall Part Fabricated by Laser Single Track Scanning via SLM

通过选区激光熔化(SLM)技术激光单道扫描成型了纯钨薄壁件,采用二维影像仪和光学显微镜分别测量了成型薄壁件壁厚和熔化道宽度,研究了激光功率和扫描速率对成型纯钨薄壁件壁厚和熔化道宽度的影响。利用光学显微镜观察了成型薄壁件表面2D和3D形貌。使用扫描电镜观察了成型薄壁件侧面粘粉情况,并分析了粘粉的原因。研究结果表明,成型薄壁件壁厚要大于熔化道宽度;随着激光功率的增大,薄壁件壁厚和熔化道宽度逐渐增大,薄壁件表面逐渐变得平坦;随着扫描速率的增大,薄壁件壁厚和熔化道宽度逐渐减小,熔化道由扭曲变得平直再变得扭曲,熔化道高度方向上的高度差先减小后增大;纯钨薄壁件由完全熔化区、球化区、半熔化区和未熔化区4部分组成。

The pure tungsten thin wall parts were fabricated by laser single track scanning via SLM.The wall thickness and molten trace width of the parts were measured by two-dimensional imager and optical microscope,respectively,and the influence of laser power and scanning rate on the wall thickness and molten trace width were investigated.The surface 2 D and 3 D morphology of thin wall parts were detected by optical microscope.The powder adhesion on the side surface of the thin wall parts was detected by scanning electron microscope and the reason for powder adhesion was analyzed.The results indicate that the wall thickness of parts is greater than molten trace width.With the increase of laser power,the wall thickness and molten trace width increase,the surface of thin wall parts becomes smooth.With the increase of scanning rate,the wall thickness and molten trace width decrease,the molten trace becomes twisted first and then straight,and twisted again,while the height difference of the molten trace decreases first and then increases.The thin wall parts consist of complete melting zone,balling zone,semi-melting zone and unmelted zone.