The Friction, Wear, and Failure Behavior of Functionalized Hexagonal Boron Nitride with Karanja Oil Blends

Abstract

This study explores lubricants derived from Karanja seed oil (Pongamia pinnata) through chemical modification and combined with hexagonal boron nitride (h-BN) to demonstrate improved load-bearing performance. The tribological properties of pure Karanja oil, chemically modified Karanja oil (MKO), and oil mixed with fatty acid functionalized h-BN (fh-BN) were assessed. Initial tests evaluated essential lubricating properties. A 50% chemically modified oil blend performed best at sliding speeds from 0.05 to 0.3 m/s. Key measurements included frictional loss, failure load, wear volume, and coefficient of friction for modified blends and fh-BN nanolubricants. The 100% modified blend (100% MKO) withstood 114% higher load before failure, and fh-BN enhanced load capacity by 107% compared to pure Karanja oil. Post run-in phase, frictional work loss was similar between 100% MKO and pure oil when tested with starvation of lubricants; however, 50% MKO and 0.025 wt% h-BN and fh-BN blends showed reduced frictional work loss. The fatty acid layer on functionalized fh-BN surfaces promotes the formation of a thin tribolayer, enhancing their overall lubrication performance. © 2024 Society of Tribologists and Lubrication Engineers.