激光直接制造技术(LDM)是基于快速成形和激光熔覆技术而发展起来的直接快速柔性制造先进技术,尤其适用于传统方法难以制造的特种材料或特殊形状金属零件。基于太空望远镜准直器特定的形状和材料要求,运用层叠激光熔覆直接制造方法,研究了W和W/Ni合金的多道熔覆特性、微观组织和激光直接制造过程的稳定性。研究表明,W和W90Ni10多层激光熔覆时后续熔覆层的宽度会越来越窄,最终形成三角形截面;而W60Ni40和W45Ni55合金具有良好的成形效果。采用激光功率2000 W,光束直径3 mm,扫描速度0.3 m/min,送粉速度8 g/min的优化工艺参数,直接制造出高度为307 mm,直径为191 mm,壁厚为3 mm,平行度不低于2/1000的圆柱状W60Ni40准直器,未出现裂纹和明显的气孔。结果表明激光直接制造技术可以制造出高质量的传统方法难以制造的特殊材料和形状的金属零件。

Laser direct manufacturing (LDM) is intensively developed in recent years to directly and flexibly manufacture metallic components with full metal density, functions and properties, especially for some specific materials or geometry. This paper presents a project work on laser direct manufacturing a novel designed collimation component for out-space hard X-ray modulation telescope. The research work contained the characteristics study of overlap multi-pass laser cladding of tungsten or tungsten nickel alloys, the microstructure analyses and the processing stability of laser direct manufacturing. The research indicated that a triangle shape clad appeared when vertically overlap W and W90Ni10 alloy. The W60Ni40 and W45Ni55 alloys showed good forming capability for manufacturing. With optimized parameters