Publication: Wear particle analysis of grease-lubricated sliding contact
Loading...
Date
2024-07-12
Authors
Foo, Zi Yong
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Continuous sliding contact can cause surface wear and generate wear particles as components slide against each other. Mitigating wear and wear particle generation is crucial for maintaining the performance and longevity of mechanical components. This study investigates wear particle generation and characteristics under various lubrication conditions over extended periods using a pin-on-plate apparatus at 100 rpm and a 10 kg load. Tests were conducted for 1 and 3 hours to evaluate both short-term and long-term effects. Four conditions were examined: dry contact and lubrication with SKF LGMT2, EAJ 7000 Lithium High Temp Grease, and formulated palm oil grease. Wear and frictional forces were recorded in real-time by sensors within the Pin-on-Disc tester. Wear particle analysis employed Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) to elucidate wear mechanisms and elemental changes. Mass loss analysis showed that dry conditions experienced the most severe wear, followed by EAJ 7000, SKF LGMT2, and palm oil grease. Friction results aligned with these findings, with palm oil grease producing the lowest friction. Elemental analysis indicated that aluminium was most severely removed in dry contact, with the highest aluminium percentage detected in wear particles, followed by LGMT2, EAJ 7000, and palm oil grease. Few particles were produced by sliding contact with palm grease, indicating its effectiveness in protecting surfaces. Oxidation was detected in dry contact conditions, while lubricated conditions markedly reduced wear and oxidation. SKF LGMT2 exhibited superior performance with lower oxidation rates and stable elemental compositions. EAJ 7000 provided moderate protection, effectively reducing wear and oxidation compared to the dry condition but not as effectively as SKF LGMT2. The formulated palm oil grease demonstrated exceptional efficacy with the least wear and friction, highlighting its potential as a sustainable and efficient alternative lubricant. These findings underscore the critical role of effective lubrication in extending the operational lifespan of mechanical components by minimizing wear and oxidation. The consistent presence of carbon in the lubricated conditions indicated continuous protection and a stable lubricating film.