Study on finish-turning of NiCr20TiAl nickel-based alloy using Al₂O₃/TiN-coated carbide tools

摘要

Al₂O₃/TiN-coated tungsten carbide tools were used for finish-turning of NiCr20TiAl nickel-based alloy under various cutting conditions. The cutting forces, surface integrity, and tool wear were investigated, and their formation mechanisms were discussed. The inter-diffusing and transferring of elements between Al₂O₃/TiN-coated tungsten carbide tool and NiCr20TiAl nickel-based alloy were studied during machining. The plastic flow of NiCr20TiAl alloy was present on the machined surface by the lower cutting forces. The flaking of coating and matrix of tools and the heavier plucking and cavities of the machined surface were induced by the higher cutting forces at higher cutting parameters. The tensile residual stress was engendered on the machined surface and increased with the cutting parameters. In view of surface quality and tool wear, the cutting speed of 60 min and feed of 0.15 mm/r are recommended, and depth of cut should not exceed 0.4 mm when Al₂O₃/TiN-coated carbide tools are used for the finish-turning of the NiCr20TiAl alloy.