US Patent:
20110151238, Jun 23, 2011
Inventors:
Michael L. Holly - St. Clair Shores MI, US
Sumie S. Thaker - Rochester Hills MI, US
Brian K. Bartnick - Ortonville MI, US
Casimir S. Jaworowicz - China MI, US
Robert G. Sutherlin - Canton MI, US
Douglas N. Reed - Milford MI, US
Assignee:
GM GLOBAL TECHNOLOGY OPERATIONS, INC. - Detroit MI
International Classification:
B32B 5/14
B05D 3/00
Abstract:
A method of forming a low-friction coating on a metal substrate includes ferritic nitrocarburizing the metal substrate to form a surface of the metal substrate, wherein the surface includes a compound zone and a diffusion zone disposed subjacent to the compound zone. After ferritic nitrocarburizing, the method includes oxidizing the compound zone to form a porous portion defining a plurality of pores, and, after oxidizing, coating the porous portion with polytetrafluoroethylene. The method further includes, after coating, curing the polytetrafluoroethylene to thereby form the low-friction coating. A low-friction coating system includes the metal substrate having the surface including the compound zone and the diffusion zone disposed subjacent said compound zone, wherein said compound zone includes the porous portion defining the pores, and a cured film formed from polytetrafluoroethylene disposed sufficiently on the porous portion so as to at least partially fill at least one of the plurality of pores.