A report describes experiments on the wear-reducing performances of six additives to perfluoropolyether (PFPE)-based fluids in the boundary-lubrication regime. The additives were a phosphate, a thiophosphate, a β-diketone, a benzothiazole, an amide/thiol, and a sulfite. Each additive was dissolved, at a concentration of 1 weight percent, in a PFPE based on hexafluoropropene oxide. The resulting formulation was exposed to the boundary-lubrication regime in a four-ball vacuum tribometer at a temperature ≈ 23 °C, an initial Hertzian stress of 3.5 GPa, and a sliding speed of 28.8 m/s. The wear rate for each formulation was determined from the slope of wear volume as a function of sliding distance.

This work was done by William R. Jones, Jr., of Lewis Research Center; Bradley A. Shogrin of Case Western Reserve University; Pilar Herrera-Fierro of Ohio Aerospace Institute; and Tzuhn-Yuan Lin and Hajimu Kawa of Exfluor Research Corp. To obtain a copy of the report, "Evaluation of Boundary-Enhancement Additives for Perfluoropolyethers," access the Technical Support Package (TSP)free on-line at www.techbriefs.com  under the Materials category,or circle no. 165 on the TSP Order Card in this issue to receive a copy by mail ($5 charge).

Inquiries concerning rights for the commercial use of this invention should be addressed to

NASA Lewis Research Center
Commercial Technology Office
Attn: Tech Brief Patent Status
Mail Stop 7 - 3
21000 Brookpark Road
Ohio 44135.

Refer to LEW-16592.

NASA Tech Briefs Magazine

This article first appeared in the May, 1998 issue of NASA Tech Briefs Magazine.

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