Hardness, friction and wear characteristics of nickel-SiC electroless composite deposits

Composite coatings constitute a new class of materials which are mostly use d for mechanical and tribological applications. Among these materials, nick el deposits with incorporation of hard ceramic particles such as silicon ca rbide (SiC), combine anti-corrosion properties (due to the presence of nick el), with mechanical and tribological performances (due to the presence of particles of SiC). In the present study, electroless Ni-SiC composite depos its with various amounts of SiC have been prepared and characterized. The f irst part of this paper considers the materials, the experimental condition s and the characterization of the coatings. The second part is dedicated to the study of the mechanical (hardness) and tribological (friction resistan ce and wear) properties of the co-deposits. Friction tests were carried out using a ball on disk tribometer. The mechanisms of wear were analysed from observations of the wear scars and their characterization using two-dimens ional and three-dimensional profilometry. The results show that increasing the size or the rate of SIC particles incorporated lead to an increase in b oth the hardness of the films and friction coefficient when sliding against a steel ball. (C) 2001 Elsevier Science B.V. All rights reserved.