Silver based composite coatings with improved sliding wear behaviour

The paper presents the possibility of improving the sliding wear behaviour of silver/diamond electroplated dispersion coatings. In respect of some properties of silver plated surfaces, especially the low hardness and poor wear resistance, a certain amount of diamond microparticles was added as suspension to the plating silver bath, in order to codeposit with silver. For this purpose, a series of samples was realized by the use of a silver cyanide electrolyte containing 10 vol% of different sized micro diamond particles (1, 0.25 and 0.1 μm). The electroplated dispersion coatings were characterised by means of scanning electron microscopy (SEM) combined with energy dispersive X-ray analysis (EDX). The sliding wear resistance of the obtained surfaces was determined using a pin-on-disc wear tester. The obtained results demonstrated that the highest wear resistance was achieved by addition of the finest diamond particles into the silver plating bath.

► The microstructure of the obtained dispersion coatings shows a homogeneous aspect.
► The finer the diamond particles, the lower the friction coefficient and the wear rate.
► Pure silver exhibited a higher degree of squeezed spalled material.
► Codeposition of finer diamond particles improves the coatings' sliding wear.