Tribological behaviour of pongamia oil as lubricant with and without halloysite nanotubes using four-ball tester

Abstract

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.