On the influence of the Counter-body Material on the Wear Rate of 316L+WC Composite Coatings processed by Laser Cladding

This work considers a metal matrix composite composed of 316L stainless steel and reinforcements of tungsten carbides (WC) particles (20 in vol.%), fabricated by laser cladding with a complex hierarchical microstructure. Pin-on-disk tests with different counter-body material (Al2O3, WC-Co, Si3N4, Steel) were performed in order to determine the wear behaviour of the composite.
The term wear rate is often used to compare the wear performance of a material. This could lead to a wrong interpretation, as the wear rate is the result of the depth and the width of the removed volume of material. By changing the counter-body material, different wear rates are observed for both counter-body and specimen because of the different wear phenomena that occur. It is observed that high wear rates correspond to a severe wear due to a tribocorrosive behaviour leading to a high depth of the track. On the contrary, lower wear rate and lower depth of the track are due to the formation of a more protective tribolayer formed at the interface between the counter-body and the specimen, leading to a better protection for both counter-body and specimen.
By combining the trends of the Friction Coefficient (CoF) and the Penetration Depth (PDe), profilometer measurements of the worn volume, post-mortem observations of the wear track and counter-body together with the characterization of the wear debris, wear phenomena associated with each counter-body/specimen pair can be better understood.