激光选区熔化自由制造异质材料零件技术研究

为解决当前激光选区熔化成型过程难以按需在零件任意位置自由布置不同材料的难题，基于多漏斗供粉+柔性清扫回收粉末原理，对异质材料零件激光选区熔化增材制造技术展开了研究，详细探讨了成型机理、粉尘污染防范机制及异质材料数据处理方法。采用CuSn10、4340两种不同的合金材料进了工艺实验验证。实验表明该方法可以较有效解决激光选区熔化成型过程异质材料布置难题，实现异质材料零件成型：（1）能自由地在不同层间或同层内不同区域按需布置不同的材料；（2）所得块状异质材料零件的铜合金材料区域Fe元素平均质量百分含量可控制在2%以下，钢材料区域Cu元素平均质量百分含量可控制在1%以下；（3）成功成型了一个具有复杂外形及微细材料区域特征的异质材料齿轮零件，零件异质材料区域不受零件复杂外形限制，可自由按需布置材料，0.5mm宽的层内异质材料区域也能被较好地表达出来，尺寸误差不超过±0.1mm。

Study on technology of free manufacturing of heterogeneous materials part by selective laser melting

In order to solve the problem of free placement of different materials at any location of a part in selective laser melting process, based on the principle of supplying powder through multiple funnels + cleaning and recovering powder through flexible scraper, the manufacturing technology of selective laser melting of heterogeneous materials part was studied. The processing mechanism, the prevention mechanism of powder cross contamination and the data processing method of heterogeneous materials part were discussed in detail. Two different materials,CuSn10 alloy and 4340 steel, were used to verify the technology. Experiments show that this method can effectively solve the difficult problem of heterogeneous materials placement in selective laser melting process, and realize the forming of heterogeneous materials parts：(1) The heterogeneous materials can be arranged freely in different layers or in different zones of one layer; (2) To a bulk heterogeneous materials part, the average mass percentage of Fe in the copper alloy region can be controlled below 2%, and the average mass percentage of Cu in the steel region can be controlled below 1%. (3) A heterogeneous materials gear part with complex shape and characteristics of narrow material region was successfully formed. The heterogeneous materials distribution of the part is not limited by the complex shape, and the materials could be arranged freely as needed. The heterogeneous material region in one layer with 0.5mm width can also be well expressed, and the dimensional error does not exceed ±0.1mm.