TRIBOLOGICAL PERFORMANCE OF BIO-BASED LUBRICANTS IN MECHANICAL SYSTEMS

Abstract

Increasing environmental regulations and sustainability priorities have accelerated research into bio-based lubricants as alternatives to petroleum-derived lubricants. This study investigates the tribological performance of selected bio-based lubricants—namely, vegetable oil derivatives (canola, soybean), ester-based synthetic bio-lubricants, and waste cooking oil blends—in comparison with a commercial mineral oil benchmark. Using ball-on-disc tribometry, friction coefficients, wear rates, and surface morphology were quantified under varying loads and sliding speeds. The bio-based lubricants exhibited significantly reduced wear rates and good frictional behavior, with ester-based formulations outperforming. Surface analyses using SEM and profilometry revealed smoother counterface surfaces post-testing in bio-lubricant samples. The results demonstrate that optimized bio-based lubricants can achieve comparable or superior tribological performance under specific operating conditions, while offering biodegradability and reduced toxicity. Limitations and avenues for optimization are discussed.