White Layer Characterization
EMSL Project ID
2486
Abstract
Metallurgists have widely reported a thin, featureless layer on the surface of sliding components in many industrires. It has been called white layer due to its resistance to chemical etching. The white layer was thought to be an untempered martensite, formed by intense frictional heating of the wear surface above the austenitization temperature, followed by rapid cooling by the bulk material acting as a heat sink. The brittle quality of this layer contributes to premature failure in sliding components. In 1999, PSU began a project that looked at the causes and characteristics of white layer. The prior theory of austenitization due to friction has been questioned. A new hypothesis of white layer formation due to a combination of strain localization and carbide dissolution has been developed. High resolution microstructural investigation is necessary to confirm this hypothesis. The use of a field emission SEM is essential to characterize the high magnification microstructure of the white layer and its underlying matrix. EDX is also key in looking for chemical differences between the two regions. Ideally, PSU would have access to the field emission SEM and its accompanying EDX system to obtain high magnification images and chemical analysis, including X-ray maps. This would allow us to get a better understanding of the characteristics and formation of white layers on worn surfaces.
Project Details
Project type
Exploratory Research
Start Date
2002-04-01
End Date
2004-06-01
Status
Closed
Released Data Link
Team
Principal Investigator