Simulation and Experimental Investigation on Electrochemical Milling of TiB2/7050 Aluminum Matrix Composites

TiB 2 /7050 aluminum matrix composite is a new particle-reinforced composite with excellent mechanical properties. However, owing to the presence of TiB 2 -reinforced particles in the material, its traditional machinability is inferior to that of the matrix aluminum alloy, and it becomes a typical difficult-to-machine material. Electrochemical milling (EC milling) is a non-traditional machining technology based on the principle of electrochemical anodic dissolution, and it is an effective way of machining difficult-to-machine metal materials. In this study, tool cathodes with concave arc surfaces that have different heights at the end of the tool are designed, and an electric field simulation and experimental investigation on the inner-jet EC milling of TiB 2 /7050 aluminum matrix composites are carried out. The electric field simulation results show that the higher the centre of the arc surface, the lower the current density. The arc surface tool allows for a more even distribution of charge through the machining area when the machining gap d = 0.3 mm, and the electric charge distribution at the machining area under the tool with an arc centre height of 2 mm is the most uniform. An experimental investigation demonstrates that a tool with a concave arc surface at the end can improve the bottom surface flatness of the machined groove but at the cost of reducing the material removal rate (MRR). The bottom surface flatness of the groove machined by the tool with a 2-mm centre height on the curved surface was 13 μm with a machining gap of d = 0.3 mm. Compared with the flat-bottom tool, the flatness of the bottom surface was increased by 94.47%, but the corresponding MRR was reduced by 29.58%