Abstract
A suite of X-ray-based techniques has been adopted for the investigation of scuffing and other tribological failure modes. Depth-profiled X-ray diffraction, reflectivity, and fluorescence are being used to gather information on additive reaction film thickness, roughness, and electron density, presence and distribution of additive elements within those layers, identification of crystalline phases in the reaction film and subsurface material, and degree and depth of deformation. The differences between the samples and equipment used in development of this approach, and the production mechanical parts and laboratory X-ray systems, are discussed, with emphasis on application of the approach in industry.