Modares Mechanical Engineering

Modares Mechanical Engineering

Numerical and Experimental Study of Tribological Behavior of Metallic Contacts under Grease Lubrication

Document Type : Original Article

Authors
Mohammad Hossein Momeni 1
Hamid Shakerin 2
Saleh Akbarzadeh 1
1 Mechanical Engineering Department, Isfahan University of Technology, Isfahan, Iran
2 Isfahan Shakerin Gearbox CO, Isfahan, Iran
10.48311/mme.2026.120954.83034
Abstract
Wear prediction in grease-lubricated mixed regimes remains a major challenge due to the coupled interactions among elastohydrodynamic lubrication (EHL) film thickness, mechanical asperity contact, and interface thermal dynamics. In this study, an integrated engineering framework is developed to analyze the tribological behavior and predict sliding wear in a pin-on-disk configuration through a modified Archard equation incorporating the asperity load share, dry wear coefficient, fractional film defect, and contact temperature. Experimental tests under normal loads of 40, 50, and 60 N and sliding velocities of 0.1 and 0.2 m/s demonstrate that grease lubrication reduces the friction coefficient to the range of 0.095–0.109 compared to dry sliding (0.52–0.70). Specifically, increasing the speed from 0.1 to 0.2 m/s reduces the friction coefficient from 0.101 to 0.095, 0.105 to 0.104, and 0.109 to 0.098 for loads of 40, 50, and 60 N, respectively. Validation against experimental wear-track profilometry confirms that the proposed framework predicts the wear volume across all test conditions with an average error of approximately 25%, establishing its capability for analyzing grease-lubricated sliding contacts.
Keywords
Tribology
Wear
Mixed Lubrication
Grease
Continuum Damage Mechanics
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Modares Mechanical Engineering
Volume 27, Issue 3
March 2026
Pages 221-237