Surface Roughness Analysis of 3D Printed Microchannels and Processing Characteristics of Abrasive Flow Finishing

Because of the low surface roughness of three-dimensional (3D) printed microchannels, in some environments, the use requirements cannot be met, and, at the same time, they are difficult to process. Therefore, a surface roughness analysis of 3D printed microchannels and post-processing using abrasive flow technology are proposed. The value of the inner surface roughness of the straight pipe part was calculated by using the least-squares method combined with the definite integral. Using the equal area principle, MATLAB curve fitting was used to numerically calculate the semicircular pipe section, and the relationship between the value of surface roughness and the bending radius of the scanning layer thickness is given. Use MATLAB image processing technology to study the processing area. The roughness of the inner wall of the pipeline was analyzed by laser confocal, stereo, and scanning electron microscopes. The results show that the roughness of the inner surface of the pipe increases with an increase in the thickness of the sweeping layer, an increase in the inclination angle, and a decrease in the radius of curvature. In the case of abrasive flow processing, the longer the processing time, the greater the grinding amount and the greater the amount of grinding outside the pipe wall in each one-way machining; further, the processing has obvious directionality.