Simulation And Parameter Optimization Of High-Speed Milling Of 6005A Aluminum Alloy Carbody Structural Part

High-speed CNC machining 6005A aluminum alloy carbody structural part is one of the key procedures in the production line of CRH3 body. However, many problems occurred in high-speed milling process, such as vibration, rib deformation and tool flaking, etc., greatly reduce the productivity of the entire CRH3 production line,. Therefore, it is necessary to study high-speed milling process of 6005A aluminum alloy structural part. This paper presents the simulation and parameter optimization of high-speed machining of 6005A aluminum alloy and its'structural part based on the high-speed machining theory using elastic-plastic finite element techniques and machining experiments.The stress-strain curves of 6005A aluminum alloy are obtained by quasi-static compression test. The material parameters in Johnson Cook flow stress model are fitted out by using least square method, and the material model of 6005 A aluminum alloy is established and verified to be right through cutting force measuring experiments.The finite element model of orthogonal cutting, oblique cutting and side milling process are established and high-speed cutting for 6005A aluminum alloy is simulated in ABAQUS software. Both rake angle and clearance angle are optimized by analysis of their effects on cutting forces, cutting temperature and tool stress by using orthogonal cutting simulation.The effects of both cutting edge inclination angle and helix angle on cutting forces is analyzed respectively by using oblique cutting and side milling simulation. The analysis results indicate that there are similarities and differences between helix angle and cutting edge inclination angle. The helix angle is optimized by the analysis results and the side milling process FE model is proved to be accurate and reasonable by milling force measuring experiment.The geometric models of 6005A aluminum alloy structural part and spiral end mill are established in PRO/E. High-speed milling of 6005A aluminum alloy structural part is simulated to analyze the equivalent plastic strain of machined workpiece and deformation of ribs. The results show that the maximum equivalent plastic strain of machined surface and deformation of ribs are decreased by reduction of cutting force and the impact that ribs bore with increasing of helix angle, rake angle and clearance angle. The equivalent plastic strain of the machined surface and ribs deformation are the smallest by using the mill tool that rake angle, clearance angle and helix angle are optimized to machine the structural part. Therefore, the possibility of rib deformation can be reduced effectively and the processing quality and efficiency will be improved by using the optimized end mill to machine the structural part.