Abstract:
Three tools made of polycrystalline cubic boron nitride (PCBN), TiAlN coated cemented carbide (two tool tip corner radii) and Al
2O
3+TiC coated cemented carbide, respectively, were used to turn TC4 titanium alloy workpiece. Wear width on flank face of the tools and surface roughness of the workpiece were measured, wear morphology of the tools was observed and wear mechanism was analyzed. Meanwhile, effects of tip corner radius on surface roughness of the workpiece and chip morphology were studied. The results show that the TiAlN coated cemented carbide tool had a longer service life than the other two tools. After machining with the TiAlN coated cemented carbide tool, the workpiece had the smallest surface roughness and the best surface quality; the wear form of the tool was mainly abrasive wear and adhesive wear. The failure mode of the PCBN tool was mainly collapse of the rake face and flank face, while the wear form of the Al
2O
3+TiC coated cemented carbide tool was mainly diffusion wear. Increasing tip corner radius was beneficial to improving chip breaking ability of the TiAlN coated cemented carbide tool and surface quality of the workpiece.