Fretting Wear-Resistant, Micro-Arc Oxidation Coatings for Aluminum and Titanium Alloy Bearings (Preprint)
Abstract
This report was developed under a SBIR contract, and has been released to the public by Infoscitex. Aluminum and titanium alloys are used as replacements for steel in gear boxes of aircraft and helicopters in both military and commercial air vehicles, due to their low density, mechanical strength and thermal conductivity. However, these alloys are susceptible to fretting wear when matched to harder steel surfaces under high loads at elevated temperatures. Anodized coatings are too thin and porous to protect these metals. Infoscitex applied a proprietary micro-arc oxidation process to produce hard, thick, and adherent oxide coatings on aluminum and titanium alloys that rendered the coated metal components resistant to fretting type wear. Selected aluminum and titanium alloy test specimens were micro-arc treated then measured for surface hardness, roughness, and adhesion to metal substrate. Block-on-Ring fretting wear tests on polished test specimens against M-50 steel were conducted in the presence of lubricant, under high loading, at ambient and 400 degrees F temperatures. Coefficient of friction and wear volume were measured versus number of test cycles. The results of efforts to improve the fretting wear resistance of aluminum and titanium alloy bearings for use in aircraft gear box applications will be discussed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2007
- Accession Number
- ADA469003
Entities
People
- B. M. Cushman
- K. J. Choppy
- R. F. Kovar
Organizations
- Infoscitex Corporation