Effect of MoS2 Nanoflakes on Mechanical and Tribological Behavior of Composite Friction Material Fabricated by Pressure‑Assisted Sintering

Effect of MoS2 Nanoflakes on Mechanical and Tribological Behavior of Composite Friction Material Fabricated by Pressure‑Assisted Sintering

The MoS2nanoflakes can be a novel candidate as a solid lubricant in fabricating friction material for automotive brake-paddisc systems. In this paper, an investigation has been made to analyze the effect of MoS2nanoflakes on the mechanical andtribological behavior of the formulated copper-free low-metallic composite friction material. Three samples, namely S1,S2,and S3,have been fabricated containing different types of solid lubricant. Sample S1had a solid lubricant as graphite, whilesamples S2and S3had graphite mixed with solid lubricant MoS2with average flake sizes of 2 μm and 50 nm, respectively. Other components included steel, PAN, and aramid as reinforcing fibers; walnut powder, barium sulphate (BaSO4), andnitrile-butadiene rubber as fillers; phenolic resin as a binder; and FeO, Quartz, and MgO as abrasives. A pin-on-disc tribometertest (ASTM G-99) was conducted to carry out the wear test at a load of 60 N, sliding velocity of 2.09 m/s, and slidingdistance of 6283 m at room temperature. A scanning electron microscope was used to study the micro-structural evolutionof worn composite friction pin material. The results show that the nano-sized MoS2solid lubricant influences the structuralintegrity of the formulated composites, which governs the friction and wear behavior. The graphite and MoS2-based frictioncomposites S2and S3perform better than the conventional friction material (S1) containing graphite in terms of physical–mechanical, thermal, and tribological properties. The specific wear rate of the S1sample is the highest (2.72 × 10–5 mm3/Nm) followed by S2(1.84 × 10–5 mm3/Nm) and S3(0.98 × 10–5 mm3/Nm) respectively. The graphite and MoS2-based frictionspecimens S2and S3showed adequate coverage of friction plateaus, reducing wear and abrasion of the counter disc.

The MoS2nanoflakes can be a novel candidate as a solid lubricant in fabricating friction material for automotive brake-paddisc systems. In this paper, an investigation has been made to analyze the effect of MoS2nanoflakes on the mechanical andtribological behavior of the formulated copper-free low-metallic composite friction material. Three samples, namely S1,S2,and S3,have been fabricated containing different types of solid lubricant. Sample S1had a solid lubricant as graphite, whilesamples S2and S3had graphite mixed with solid lubricant MoS2with average flake sizes of 2 μm and 50 nm, respectively. Other components included steel, PAN, and aramid as reinforcing fibers; walnut powder, barium sulphate (BaSO4), andnitrile-butadiene rubber as fillers; phenolic resin as a binder; and FeO, Quartz, and MgO as abrasives. A pin-on-disc tribometertest (ASTM G-99) was conducted to carry out the wear test at a load of 60 N, sliding velocity of 2.09 m/s, and slidingdistance of 6283 m at room temperature. A scanning electron microscope was used to study the micro-structural evolutionof worn composite friction pin material. The results show that the nano-sized MoS2solid lubricant influences the structuralintegrity of the formulated composites, which governs the friction and wear behavior. The graphite and MoS2-based frictioncomposites S2and S3perform better than the conventional friction material (S1) containing graphite in terms of physical–mechanical, thermal, and tribological properties. The specific wear rate of the S1sample is the highest (2.72 × 10–5 mm3/Nm) followed by S2(1.84 × 10–5 mm3/Nm) and S3(0.98 × 10–5 mm3/Nm) respectively. The graphite and MoS2-based frictionspecimens S2and S3showed adequate coverage of friction plateaus, reducing wear and abrasion of the counter disc.