Font Size: 

The compressive residual stresses are particularly beneficial on the surface. It tends to increase fatigue strength and fatigue life, slow crack propagation, and increase resistance to environmentally assist cracking. Compressive residual stress can be achieved by coating process and surface treatment like blasting. Therefore, the research is concern on the behavior of compressive residual when applied coating followed by micro blasting on the surface. Titanium Aluminum Nitride (TiAlN) was deposited onto high speed steel substrate by reactive direct current (DC) magnetron sputtering with targets of titanium and aluminum. Thereafter the coated TiAlN was micro blasted with alumina (Al₂0₃) powder of the size of 48 µm applied to the coated surface to induce compressive residual stress. Taguchi method was utilized with four control factors of impact angle, time and distance between sample and blasting nozzle. Apart from that, the factors were also inclusive of four noise factors to get the most optimum condition. X-ray diffraction (XRD) analysis showed that TiAlN coating phase without blasting had lower compressive residual stress rather than the TiAlN coating phase combined with micro blasting. The results showed that micro blasting with alumina oxide powder increased 52.5% surface micro hardness and 57.6% adhesion strength of the TiAlN coated high speed steel.

Compressive residual stress, TiAlN coating , micro blasting, PVD (Physical Vapor Deposition), Taguchi Method