Effect of Grinding Parameters on Industrial Robot Grinding of CFRP and Defect Formation Mechanism

The use of industrial robots for grinding CFRP is a green processing method. This method not only allows in-situ repair to reduce unnecessary waste of resources, but also produces no excessive contaminants. The effect of various process parameters, including grinding directions, the mesh size of grinding heads and rotating speed, on the grinding quality of Carbon Fiber Reinforced Polymers (CFRP) using industrial robots was investigated. The mechanism of grinding defects was also studied. According to the experimental results, the CFRP grinding process is mainly controlled by the rotating speed, number of grinding heads, and grinding direction. In particular, high-speed grinding helps to improve the surface quality of CFRP. In turn, the use of diamond grinding heads with too small or too large particles may reduce surface quality. Grinding quality changes with the grinding direction. In the grinding direction between 0 degrees and 90 degrees, the surface roughness increases with the angle (but drops at 60 degrees), and The same trend is observed in the grinding direction between 90 degrees and 150 degrees, whereby the surface roughness increases with the angle (but drops at 120 degrees). The surface quality of CFRP is thereby improved after grinding in the direction of 0 degrees, 60 degrees, 120 degrees and 180 degrees. Furthermore, the fiber pull-out occurs, when the feed direction and fiber orientation are aligned. Finally, the low-frequency vibration easily causes fiber pull-out defects.