The present work was aimed to study the friction and wear behaviour of graphene nanoplatelets (GNPs) under extreme pressure conditions as an anti-weld additive for neem oil. The effect of neem oil, blended with various loading of GNPs on the friction and wear characteristics has been investigated. From the experimental results, it was found that 1 wt.% of GNPs in neem oil showed the least coefficient of friction and smoother wear scar diameter. The extreme pressure test was performed on neem oil with and without GNPs as per ASTM standards. The extreme pressure test results indicated the improvement in seizure load of neem oil by 27.8% at 0.5 wt.% of GNPs as compared to pure neem oil. Optical microscopy of worn steel ball surface revealed the pit formation and the formation of wedge cutting edge in GNPs modified neem oil.

This comprehensive review article provides a cumulative insight into the tribology and the surface topography of the components of the electric vehicles (EV) and hybrid electric vehicles (HEV) that are subjected to friction and wear under their conventional operation. The comparison between the components that are native to EV and HEV and components that are common for both vehicle types are discretely discussed. The overall influence of such a tribology-critical component on the life and efficiency of the EV and HEV is indicated in this article as well. Identification of the research gaps in the key areas paves an avenue to channel the research and focus upon improving the efficiency of EV and HEV by improvising the design, materials, power harness, and lubrication techniques. Finally, the future scope of the global EV and HEV markets are discussed to signify the importance of the studies on the tribology of the trending automobile field.

This investigation was performed to study the effect of hexagonal boron nitride (hBN) on abrasion wear behaviour of polyetherketone (PEK) composites. PEK composite were examined for two-body abrasive wear (2-BAW) with silicon carbide abrasive paper and three-body abrasive wear (3-BAW) test with silica sand according to ASTM standards. The Taguchi L9 design of experiment was employed to optimize the wear operating parameters. The optimized conditions with 10 N load, 320 grit size and 10 wt. % of hBN resulted minimum specific wear rate (Ks). Unfilled PEK portrayed better impact strength, hardness, lower density and lower Ks under 3-BAW. However, 10 wt. % of hBN was beneficial under 2-BAW condition. The SEM micrographs were analyzed to probe the wear mechanism involved in the abrasion process. Surface roughness (Ra) value measured was compared with Atomic Force Microscopy (AFM) and it was found that both the values are in good agreement. Multi-objective optimization by ratio analysis (MOORA) was implemented to rank the overall performance of PEK composites under study.

In this work, the effect of graphene nanoplatelets (GNPs) on the physico-mechnaical properties of short carbon fiber (SCF) reinforced polyamide 66/thermoplastic copolyester elastomer composites was investigated. The composites were fabricated with extrusion followed by injection molding method. The host matrix, fiber plus host matrix and graphene nanoplatelets loaded hybrid composites were examined for density, hardness, tensile, flexural and impact properties according to the governing ASTM standard. Fiber reinforcement decreased void content to < 1 % but GNPs were able to keep void content under limits. Hardness and impact strength augmented with 2 wt. % graphene nanoplatelets loading, owing to superficial dispersion developing the relationship between the hardness and impact strength. Graphene nanoplatelets loading benefitted the tensile property. However, the same has a deteriorating effect on flexural strength. Flexural modulus increases until 2 wt. %. Improvement in mechanical properties upon GNPs loading is very feeble when compared to the enhancement with SCFs loading to the host. Upon comparing the properties, it was observed that 2 wt. % of graphene nanoplatelets performed admirably and was recognized as an optimum filler loading. Morphology of fractured surfaces was studied by analyzing the scanning electron microscope images to understand the various features and mechanisms.

This investigation is conducted to obtain the wear and friction behavior of halloysite nanotubes (HNTs) as an antiwear additive to bio-based pongamia oil. The tribological tests were carried out using a four-ball tester (ASTM D-4172). The variation of viscosity of bio-based pongamia, madhuca indica and neem oils is also evaluated in conformity with IP70/62. The test results were compared with synthetic petroleum-based lubricant (SAE20W40). The experimental test data showed that pongamia oil containing HNTs (1.5 wt.%) has superior tribological characteristics and smoother wear scar diameter compared to other combinations of pongamia oil without additives and other bio-based oils.