Laser trimming and performance analysis of mill-grinding tools for carbon fiber–reinforced plastics

Carbon fiber–reinforced plastics (CFRP) are widely used in the aeronautic aerospace and manufacturing industries due to their excellent performance. However, due to the structural characteristics of CFRP, its process efficiency is low, the surface quality is poor, and it is easy to cause tool wear. In this study, the effect of five-tool types (conventional milling tool, rhombus tooth milling tool, electroplated mill-grinding tool, slotted mill-grinding tool, laser-trimmed milling-grinding tool) and process parameters (spindle speed, feed rate, radial cutting depth) on tool life, process quality, and accuracy was systematically studied. The cutting force of the three types of electroplated diamond mill-grinding tools and the surface roughness of the processed CFRP are lower than that of the conventional milling tool and larger than that of the rhombus tooth milling tool. The residual chip on the surface of the slotted mill-grinding tool is less than that of the electroplated mill-grinding tool, but its cutting force and the surface roughness of the workpiece are greater than those of the electroplated mill-grinding tool. The main cutting and radial force of the trimmed mill-grinding tool are 9.5 N and 1.26 N, respectively. The surface roughness is about 2.524 µm. Due to the laser-trimmed mill-grinding tool having neat and sharp edges which can shear carbon fiber effectively, there are no obvious burrs on the processed CFRP. Moreover, the processed surface roughness was significantly reduced, and only a slight wear of the tool occurred. More importantly, the process debris can easily flow out of the straight groove of the laser-trimmed mill-grinding tool, resulting in a sharp edge of the tool, which reduces the cutting force. The laser trimming has a slight effect on the surface roughness but a more important effect on the cutting forces. The overall process performance of the laser-trimmed mill-grinding tool is close to that of CFRP special tool (rhombus tooth milling tool), but its price is about one-fiftenth that of special tools. Therefore, the electroplated diamond milling tool with improved structure and optimized process parameters can be an ideal tool for mill-grinding CFRP.