Micro-blasting effect on fracture resistance of PVD-AlTiN coated cemented carbide cutting tools

Abstract The dry micro-blasting effects on the fracture resistance of PVD-AlTiN coated cemented carbide cutting tools were studied. The AlTiN coatings with the composition of (Al 0.60 Ti 0.40 )N were deposited using cathodic arc evaporation method. The two types of coatings, which had a compressive residual stress of 0.1 GPa ( Low-σ ) and 2.6 GPa ( High-σ ), were prepared. The coated samples were subjected to the dry micro-blasting treatment by Al 2 O 3 grains at pressures of 0.11 MPa, 0.14 MPa, and 0.17 MPa. A milling test using AISI 4140 (42CrMo4) steel as the workpiece material was carried out for evaluating the fracture resistance of the prepared samples. The tool life cutting distance of Low-σ sample micro-blasted at 0.14 MPa and 0.17 MPa was 2.9 m and 7.2 m, respectively, largely extended as compared to that of as-deposited Low-σ sample, 1.0 m. On the other hand, the tool life of High-σ sample micro-blasted at 0.14 MPa was 8.6 m, almost same with that of as-deposited High-σ one, 8.8 m. Those results indicate that the dry micro-blasting effect on the fracture resistance is larger for the Low-σ coating than for the High-σ one.