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30NiCrMoV12 quenched and tempered samples were coated with 4 μm of CrN produced by cathodic arc deposition technique. Micro-blasting treatment was performed on the coated samples, after the deposition, to remove defects like droplets from the surface. The fatigue limit was assessed and compared to that of the bare steel. A basic characterization of the coating/substrate was performed (hardness, roughness and adhesion). The residual stress distribution next to the surface of the samples was measured and its effect on the fatigue limit was evaluated. The micro-blasting treatment does not adversely affect the hardness and the adhesion of the coating nor the fatigue resistance of the coated samples.

This paper studies the effect of artificial aging on the wear resistance of the recently developed Zn-15Al-1Cu-Mg alloy. Pin-on-disk tests were performed to evaluate the evolution of friction coefficient and wear rate on samples produced via spin casting. Hardness and tensile properties were also monitored as a function of aging time. After the tests, wear scares and fracture surfaces were analyzed by scanning electron microscope, in order to understand the damage and the failure mechanisms. It was found that hardness and tensile strength decrease with the aging time, while both friction coefficients and wear rates increase.