为解决金属超轻结构零件设计技术复杂、设计周期长、难添加蒙皮进行增材制造等难题, 提出一种基于激光选区熔化增材制造工艺的金属零件自动超轻结构化设计方法: 根据激光选区熔化工艺特点, 编制程序将原始零件CAD模型自动转化为设定孔隙率的带蒙皮类蜂窝状超轻结构零件模型, 且其数据可直接驱动设备实现零件增材制造。研究了带蒙皮超轻结构的构造形式及设计方法; 探讨了合适的成型棱长及合理蒙皮结构形式; 成功实现复杂零件自动带蒙皮超轻结构化设计及增材制造, 所得零件孔隙率误差2.79%,表明能较准确按预期减重。该方法能根据原始零件CAD模型自动、快速地构建带蒙皮金属超轻结构零件模型, 大大减轻该类零件设计负担及提高其实用性。

In order to solve the problems when designing super-light structure part such as needing complex design techniques, long design cycle, difficult to add skin if making it by additive manufacturing technology, based on selective laser melting technology, a method which can automatically add skinned super-light structure to traditional metal part CAD model was put forward in this paper. Considering the selective laser melting process characteristics, through an algorithm, a skinned super-light quasi-honeycomb structure part model with a preset porosity can be automatically designed by transforming an original CAD model. And the new part model data format can direct drive a selective laser melting machine for additive manufacturing without any data format transformation. The construction and design method of the skinned super-light structure of metal part were studied. Through process analysis, appropriate processing unit length and reasonable skin tissue of super-light structure metal part were gotten. The above method was tested successfully on a part model with complex shape in a selective laser melting experiment. The error of porosity is 2.79%, which means that this method can accurately reduce part mass according to preset porosity value. Therefore, in this way, skinned super-light structure part can be design automatically and quickly based on an original CAD model without super-light structure, the burden to design this kind of parts will be greatly reduced, and the practicability of the parts made through this method will be improved greatly.