Aluminum and alumina/MoS₂/cellulose derivative composite: design and performance

Abstract

Nanoparticles were added to improve the tribological performance of the biopolymer-based composite films. Aluminum and alumina were used as additives. The matrix of the composite was MoS2/hydroxypropyl methylcellulose (HPMC). The ternary additive/MoS2/HPMC hybrid composites were successfully prepared via solvent evaporation. The surface morphology, thickness, microstructure, and wear scars were analyzed using scanning electron microscopy. X-ray diffraction was used to analyze the crystal structures of the nanoparticles in the composite films. Finally, a wear test was conducted to determine the tribology behavior and was discussed using the third-body theory. Because of the high surface-area-to-volume ratio of the additives, nanoparticles were exposed and densely distributed on the composite surface. Disclosed nanoparticles caused peaks and valleys and showed more significant undulations, prompting a highly rough surface. The addition of nanoparticles enhanced the load capacity of the composite films by 155%. In the meantime, nanoparticle additives significantly reduced the coefficient of friction by 50% and improved anti-wear performance by five times. The nanoparticles in the wear scar exhibited an excellent third-body mechanism during the wear process, coordinating the velocity accommodation mode between the two rubbing surfaces and the transfer load.

Assessment of machinability behaviour of LM24 – nano Al2O3 – gr hybrid composites through stir casting technique

“…In the context of MMCs reinforced with SiC or B 4 C having poor surface roughness, as reported by Kathirvel and Palanikumar [11] and Siddesh Kumar et al [5], Al 2 O 3 can be a better reinforcement to improve machinability characteristics. The reinforcement of 5 vol % nano alumina particle is equivalent to 35 vol % in the micron size range, and hence, nano alumina is the preferred reinforcement to improve the strength [14]. Machinability characteristics have been improved by reinforcing with SiC+Gr in MMC made of LM25 aluminium alloy [15].…”