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为快速直接制造具有复杂曲面的个性化金属零件,需要保证激光选区熔化(SLM)成型曲面特征的表面成型质量。通过正交实验获得Ni Cr合金优化工艺参数,采用S型正交层错扫描策略成型两种柱面体模型;在超景深显微镜、扫描电镜下观察成型件内、外侧曲面表面形貌,并测量相应表面粗糙度。结果表明:成型不同空间位置摆放的曲面零件,各层面轮廓误差、层面间台阶效应的逐层堆叠最终使曲面形成台阶状、网结状形貌,成型倾斜切角小于60°的悬垂曲面时因粉末粘附严重甚至会形成条虫状、粒球状形貌;表面粗糙度Ra值与曲面特征表面形貌变化规律具有相关性,这为提高SLM成型曲面零件的表面成型质量提供了重要参考。
In order to quickly and directly fabricate personalized metal parts with complex surfaces, it is necessary to ensure the quality of the surface forming of the Laser Selective Melting (SLM) forming surface features. The optimum parameters of NiCr alloy were obtained by orthogonal experiments. Two kinds of cylindrical model were formed by S-type orthogonal stacking fault scanning method. The surface morphology of the inner and outer curved surface of the molded part was observed under the microscope and scanning electron microscope. Surface roughness. The results show that when the curved surface parts placed in different spatial locations are formed, the contour error of each level and the step-by-step stacking effects of the layers eventually result in a step-like surface and net-like topography. When forming an overhanging surface with a tilt angle less than 60 ° Due to the serious adhesion of the powder, the worm-like and pellet-like morphology will be formed. The relationship between the surface roughness Ra and the variation of the surface features of the curved surface is significant. This provides an important reference for improving the surface forming quality of SLM profiled surface components.