利用自主开发的选区激光熔化设备以钴铬合金为成型材料，在进行了系统的工艺优化研究的基础上，对选区激光熔化(SLM)制件成型过程中表面粗糙度演化、微观形貌、致密度以及硬度之间的内在联系进行了研究。研究发现：成型过程中粉层的熔化收缩以及厚度的累积是造成成型质量变差的重要原因；较小的表面粗糙度累积效应，可大大减少成型件内部的孔隙数量从而提高致密度，粉层厚度的降低是减小表面粗糙度累积效应和提高致密度的关键；制件的宏观硬度比显微硬度对制件致密度存在更显著的依赖关系：致密度越大，宏观硬度越大。通过优化工艺制得的工件致密度达到98.04%，宏观硬度为40HRC，符合美国材料实验协会(ASTM)标准。

A systematic study on the three dimensional (3D) prototyping of cobalt-chromium alloys are carried out by using a self-developed laser melting equipment. The optimizations of properties which involve the surface roughness, surface morphology, relative density, hardness of the workpieces are further discussed. Results show that melting shrinkage and thickness accumulation of the powder layer are two important factors to affect the forming quality; the smaller of the surface roughness cumulative effect, the less pore are observed, which lead to a high relative density; Furthermore, macro-hardness of the part has a significant dependence on relative density. The relative density of 98.04% and the macro-hardness of 40HRC under the optical process parameters are obtained, conforming to American society of testing materials (ASTM) standards.