Effects of solid lubricants, load, and sliding speed on the tribological behavior of silica reinforced composites using design of experiments

Abstract

In the present study, the effects of solid lubricants, braking load and sliding speed on the tribological behavior of Cu/silica composites were investigated using design of experiments and statistical methods. Three types of composites were prepared using different types of solid lubricants (h-BN, graphite, and MoS2) by powder metallurgy. The wear and friction behavior of the composites were evaluated for a range of braking loads (300, 600, and 900 N) and sliding speeds (3, 6, and 9 m/s) in a subscale dynamometer. The composites were characterized for density, hardness, microstructure, wear surface morphology and surface roughness properties. A statistical model was developed to identify the significant factors affecting the wear resistance of the composites. The key findings of our study are: (1) MoS2 reinforced composites possess the highest density, densification, hardness, and lowest surface roughness among the composites, (2) MoS2 is the most effective lubricant in improving the wear resistance of the composites for the selected experimental domain, (3) Amongst the solid lubricant, brake load and sliding speed, the solid lubricant is the most significant factor affecting the wear resistance of the composites, (4) graphite reinforced composites provide higher braking performance at 3 m/s for all loading conditions whereas both h-BN and MoS2 reinforced composites provide better braking performance among composites at higher speed (>3 m/s) and load (>300 N) conditions.