螺杆式金属3D打印喷头设计与成形质量优化研究

Study on Screw Type Metal 3D Printing Nozzle Design and Optimized Forming Quality

针对桌面级送丝式金属3D打印系统存在的打印材料成本昂贵的问题,设计了螺杆式金属3D打印喷头,实现了对粉末状和颗粒状316L-Pom复合材料的打印成形.基于打印工艺参数优化实验,发现影响打印件线宽误差和面粗糙度的主要因素为挤出流量,在最优面打印参数的基础上,走壁次数是影响打印件尺寸精度的最主要参数.对比分析螺杆式金属3D打印喷头与送丝式金属3D打印喷头的成形质量,发现螺杆式金属3D打印喷头的尺寸误差和面粗糙度Sa均大于送丝式金属3D打印喷头,这主要是因为螺杆挤出过程中存在挤出流量的波动.

In response to the high cost of printing materials in desktop wire-feed metal 3D printing systems,a screw type metal 3D printing nozzle has been innovatively designed to achieve the printing and forming of powder and granular 316L-Pom composite materials.Based on the optimization experiments of printing process parameters,it has been found that the main factor affecting the line width error and surface roughness of the printed piece is extrusion flow rate.On the basis of the optimal surface printing parameters,the number of wall passes is the most important parameter that affects the size accuracy of the printed piece.By comparing and analyzing the forming quality of screw type metal 3D printing nozzles and wire-feed type metal 3D printing nozzles,it has been found that the size error and surface roughness Sa of screw type metal 3D printing nozzles are greater than those of wire-feed type metal 3D printing nozzles,which is mainly due to the fluctuation of extrusion flow during the screw extrusion process.