“Glazes” produced on Nickel-base Alloys during High Temperature Wear

Abstract

BECAUSE of the importance of nickel-base alloys in the aerospace industry, and in particular of the mounting cost of replacing components in gas turbine engines¹, there has been increasing interest in the friction and wear of these alloys^2–4. It has been suggested^5–6 that a shiny, glassy-looking film, designated a surface “glaze”, plays a significant part in reducing friction and wear during sliding of the alloy surfaces at elevated temperatures. We present here further data on the structure and formation of this glaze and its mechanism of protection. Extensive observations on the structure, composition, formation and properties of these glazes occurring on the alloys ‘Nimonic’ 75, ‘Nimonic’ C263, ‘Nimonic’ 108 and ‘Incoloy’ 901 have been made by optical and scanning electron microscopy, electron diffraction, electron probe microanalysis, ion microprobe mass spectrometry and electron spectroscopy, as part of a research programme into the friction and wear behaviour of these alloys at temperatures from 20° C to 800° C.