Thermophysical and wear properties of eco-friendly nano lubricants
K.M.B. Karthikeyan, J. Vijayanand, K. Arun, V. Seshagiri Rao
Abstract
Nano lubricants are widely used from heavy machinery to compact equipment to enhance their reliability. The research towards developing eco-friendly and biodegradable lubricants using natural oils has attracted the lubrication industries worldwide in recognizing the sustainable agrarian initiatives towards developing innovative green technologies. An attempt was made to investigate the use of vegetable oil-based nano lubricants prepared by dispersing molybdenum disulfide (MoS 2 ) nanoparticles with the raw castor and olive oils, without adding surfactants or property modifiers. The prepared nano lubricants were tested for lubrication performance using a pin-on-disc tribometer, with EN31 as disc material and aluminum Al2024 as pin material. The wear study results are compared with the commercially available mineral oil, SAE20W40 multigrade engine oil . The castor and olive oil-based nano lubricants exhibited good thermal conductivity , higher flash point, and fire point, with better heat-carrying capacity comparatively with SAE20W40 engine oil . The study reported a 43% and 37% reduction in wear for a continuous sliding of 5 min, with castor and olive oil-based nano lubricants respectively compared with dry lubrication. Also, 56% and 51% improvement in thermal conductivity was observed for castor and olive oil reinforced with 0.7 wt% of MoS 2 nanoparticles respectively, compared with SAE20W40 engine oil. The study revealed the possibility of using vegetable oil-based nanofluids as functional lubricants, which has better replacement potential with synthetic or petroleum-based mineral oils for tribological applications.