EDM of CFRP in high-speed mist medium based on a 6-DOF robot
摘要
Carbon fiber reinforced polymer (CFRP) is a novel advanced composite material with extensive application prospects. Owing to its inherent characteristics of high strength, high hardness, and poor thermal conductivity, traditional machining methods confront significant challenges in terms of machining accuracy, surface quality, and tool wear. Electrical discharge machining (EDM) involves no direct contact between the electrode and the workpiece during the machining process, thereby rendering it suitable for the machining of difficult-to-cut materials. Nevertheless, the conventional EDM process for CFRP is plagued by issues such as the dielectric contamination and constrained machining dimensions. To address the aforementioned problems, this study innovatively proposes the adoption of a 6-degree-of-freedom (6-DOF) robot-integrated EDM machine for performing EDM on CFRP in a high-speed mist medium, aiming to achieve efficient, high-quality, and green machining of CFRP. In this research, the material removal mechanism and surface damage formation mechanism of CFRP during EDM in a high-speed mist medium were systematically analyzed. Based on single-factor experiments of through-hole machining, the influences of key process parameters including air pump pressure, pulse frequency, duty cycle, and peak current on the machining efficiency and surface quality were investigated in depth. A deep hole with a depth of 18 mm was machined on CFRP via EDM in a high-speed mist medium using a 6-DOF serial robot. Additionally, EDM milling of four complex trajectories, namely butterfly shape, rocket shape, crab shape, and clover shape, was successfully accomplished. The feasibility and effectiveness of the 6-DOF serial robot-based EDM method for CFRP in a high-speed mist medium were verified. The proposed method provides a novel technical approach for the low-cost, green, high-quality, and efficient EDM of large-scale CFRP components, exhibiting broad application prospects.