Study on the influence of PCD micro milling tool edge radius on the surface quality of deep and narrow grooves

The deep and narrow groove structure has wide applications in micro-devices such as high-frequency circuits, micro heat pipes, microchannels, etc.. It has been involved in various fields, including aerospace, electrocommunication, and medicine. However, as the deep and narrow groove structure shrinks, the processing accuracy and surface quality become challenging factors limits its further development. The radius of the micro-milling cutter edge plays an important role in precision and surface quality. Therefore, this paper conducts a systematic experimental study on the edge radius using custom-made PCD micro-milling cutters and commercially available cemented carbide milling cutters. This study investigated the influence of three different cutting-edge radius, 1.73 μm, 2.39 μm, and 2.97 μm, of PCD micro-milling cutters and varying feed rates per tooth on milling surface morphology and burr formation. A comparison was also made between the cutting performance and machining quality of PCD micro-milling cutters and cemented carbide micro-milling cutters. The results indicated that the machining quality of deep, narrow grooves is significantly related to the cutter's cutting-edge radius, tool material, and milling parameters. PCD tools with smaller cutting-edge radii produced micro-grooves with an optimal surface roughness of approximately 40 nm and minimal surface burrs under the same parameters. Therefore, using PCD micro-milling cutters with a smaller cutting-edge radius is crucial in improving the quality of deep and narrow groove machining.