Wear behavior of silicone rubber/carbon black coatings on 6061 aluminum alloy surfaces

In this paper, the effects of structural and process variables on wear resistance of silicone rubber/carbon black coatings on 6061 aluminum alloy surfaces are studied. Testing parameters have been optimized for maximum wear resistance based on taguchi orthogonal design with six important parameters, viz. polydimethylsiloxane (PDMS) molecular weight, oxime/OH ratio, catalyst weight percent, pigment weight percent, surface preparation method and adhesion promoter type. The analysis of variance showed that the wear resistance strongly depends on oxime/OH ratio and catalyst weight percent. PDMS molecular weight and pigment weight percent also have intermediate effects. Neither the surface preparation method nor adhesion promoter type had any effects on wear resistance in this study. The optimum sample was prepared according to the best levels of each factor and the wear resistance in optimum conditions was reasonably in agreement with the experimental data. Scanning electron microscopy analysis of wear surface and debris showed two mechanisms: cohesive wear with fatigue mechanism and interfacial wear with adhesion mechanism.

► Wear resistance strongly depends on the cross-linker and catalyst weight percent.
► PDMS molecular weight has intermediate effects on wear resistance.
► Pigment weight percent has intermediate effects on wear resistance.
► Pretreatment and adhesion promoter types don’t have effects on wear resistance.
► The main wear mechanisms were cohesive wear and interfacial wear.