An imprint method to produce surface asperities for EHL and RCF experiments

Area of Science:

• Materials Science
• Mechanical Engineering
• Tribology

Background:

• Surface asperities significantly influence tribological system performance.
• Understanding asperity behavior under extreme conditions is crucial for predicting component lifespan.
• Existing methods for asperity creation lack control over size, strength, and initiation sites.

Purpose of the Study:

• To develop a controlled method for fabricating single, well-defined surface asperities.
• To assess the durability and behavior of these engineered asperities under simulated service conditions.
• To provide a tool for investigating rolling contact fatigue and lubrication phenomena.

Main Methods:

• Utilized an imprint technique involving rolling a hard, indented disc against a softer disc.
• Controlled asperity height by adjusting applied contact force, inducing plastic deformation.
• Subjected the created asperities to over 35 million elastohydrodynamic lubrication (EHL) cycles.

Main Results:

• Successfully created well-defined, micrometre-high surface asperities.
• Engineered asperities demonstrated exceptional durability, surviving >35 million EHL cycles.
• The method allows precise control over damage initiation sites for defect analysis.

Conclusions:

• The developed imprint technique offers a reliable method for producing robust surface asperities.
• This technique facilitates experimental studies on rolling contact fatigue and the run-in process.
• The ability to control asperity characteristics opens avenues for investigating deformation under severe contact conditions.