为解决复杂结构金属梯度材料零件制造技术的难题, 对成分梯度材料零件的激光选区熔化成型方法展开了研究。通过零件梯度设计法结合多组扫描路径数据文件及一个txt格式文件, 实现了成分梯度材料零件增材制造数据的获取; 通过双轴摆动的粉末实时混合均布装置实现了梯度成分粉末的实时混合及均布; 采用柔性清扫回收原理解决激光选区熔化制造梯度材料零件时同层内不同粉末的清理回收问题。利用自主研发的梯度材料零件激光选区熔化成型系统展开了实验验证。获得了4340+CuSn10梯度材料零件, 颜色上呈明显的梯度过渡, 对其前侧面及上表面进行EDS分析, 发现中间3个梯度区域Fe的平均质量百分比在垂直方向分别为4.94%, 36.49%, 59.16%, 在水平方向分别为1288%, 41%, 53.59%, 在不同层之间、同一层不同区域之间均呈梯度变化。该方法可实现成分梯度材料零件自由增材制造, 为该类零件的制造提供了新的选择。

A selective laser melting method for manufacturing the composition gradient material part was investigated to solve the problem of manufacturing metallic gradient material parts with complex structures. A composition gradient design combined with several groups of scanning path data files and a material txt format file was proposed to obtain additive manufacturing data of the composition gradient material part. A real-time powder mixing and distributing device was used to mix and distribute the composition gradient powder by swinging a hopper along two axes. The principle of flexible cleaning and recycling of powder was used to clean and recycle different powders in the same layer during the manufacturing of the gradient material part through selective laser melting. The experimental verification was carried out using a self-developed selective laser melting system for forming of gradient material part. A 4340+CuSn10 gradient material part was manufactured during the experiment, which showed a significant gradient change in color. Energy-dispersive X-ray spectroscopy analysis on the front side and the upper surface of the part showed that the average mass percentages of Fe in the middle three gradient areas were 4.94%, 36.49%, and 59.16% in the vertical direction, and 12.88%, 41%, and 53.59% in the horizontal direction. The composition of the experimental sample gradually changed in different layers and different regions of the same layer, which verified the feasibility of the method and provided a new choice for the manufacturing of composition gradient material parts.