The effects of mechanical properties of substrate and coating thickness on the effective rebound hardness of electroplated nickel surfaces were studied in the light of the comparison with a previous study for the Vickers hardness [1]. Three kinds of hammer are used to elucidate the effects of the mass of the hammer and the radius of curvature of the indenter. The motion of hammer was measured using the laser Doppler vibrometer, and was also analyzed using the elastoplastic finite-element method. The impact force and the coefficient of restitution for the hammer with a fixed mass and falling height increase with increasing radius of curvature of the indenter. It has also found that there exists the critical coating thickness, over which the substrate does not influence the measurement. The critical coating thickness increases with increasing mass of the hammer and increasing radius of curvature of the indenter, and depends on the size of the plastic zone in the coating.
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