M. K. Stanford, C. DellaCorte, NASA Glenn Research Center, Cleveland, OH
LCR304 is a solid lubricant coating composed of Ni-10Cr, Cr2O3, BaF2-CaF2 and Ag and developed for dimensional stability in high temperature air. This coating is a modification of PS304, which differs in that the Ni-Cr constituent contains 20wt% Cr. The tribological characteristics of LCR304 were evaluated by pin-on-disk and foil air bearing rig testing from 25° to 650°C and compared to previous test results with PS304. For both tests, the friction coefficient decreased as temperature increased from 25° to 650°C. Wear generally decreased with increasing temperature for all pin-on-disk tests. LCR304 coated components produced the least wear of Inconel X-750 counterface materials at 427 and 650°C. These results indicate that the LCR304 coating has potential as a replacement for PS304 in, for example, low cycle (minimum wear) applications where dimensional stability is imperative.
Summary: This paper reports friction and wear characteristics of LCR304, a plasma spray deposited coating that is a modified version of PS304. Specifically, the nickel-chromium constituent in LCR304 is 90wt% Ni - 10wt% Cr compared to 80wt% Ni - 20wt% Cr in PS304. The modification is thought to enhance coating environmental durability.
