Vickers microhardness evaluation of multilayer platings for electrical contacts

A test procedure is described which utilizes the composite microhardness rendered by a superficial Vickers test. At moderate loads (typically P=100 and 200 g) the superficial hardness reading yields information on the concerted influences (thicknesses and hardnesses) of all the films deposited over the substrate. From the Vickers microhardness measurement one can determine the properties (thickness and intrinsic hardness) of the surface film. Experimental data and the computational procedure are described for relatively thin platings, i.e. t/d values not exceeding 0.2. The role of the properties for each layer in a composite is investigated. An error analysis is given for evaluating the potential accuracy inherent in practical measurements.<>