Effect of Soft Reinforcement Particles on Microstructural, Mechanical, and Tribological Properties of Sintered Copper-Based Brake Composite Friction Material

Abstract

The main objective of the work is to investigate the friction and wear behavior of sintered copper-based brake composite friction material with a change in the volume percentage of soft reinforcement particles namely MoS₂ by pin-on-disc tribometer for medium-duty automotive applications. The composite brake friction material contains copper (Cu) as a matrix, tin (Sn) as an additive, silicon carbide (SiC) and molybdenum disulfide (MoS₂) as hard and soft reinforcement particles and barium sulfate (BaSO₄) as filler. These hybrids copper-based brake composite friction (pin) samples are successfully prepared by a change in compositions of MoS₂ from 0 to 5 vol. % in the step of 1 vol. % and the characterizations of friction samples are studied to understand the physical and mechanical properties such as density, hardness, and compressive strength. Finally, the dry sliding friction and wear test is conducted against grey cast iron material (disc) at constant load and sliding speed of 50 N and 5 m/s respectively using pin-on-disc equipment under room atmosphere. Based on the analysis of the result, the developed copper-based brake composite friction sample with 2 vol. % of MoS₂ has shown better mechanical and tribological properties among other compositions. Further, post-test analysis on the worn-out sample surfaces using a field emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS) revealed that change in wear mechanisms from abrasion to adhesion as an increase in the volume percentage of MoS₂.