Accession Number : ADA336490

Title :   A Focused Fundamental Study of Predicting Materials Degradation & Fatigue. Volume 1

Descriptive Note : Final rept. 1 Jun 93-31 May 97

Corporate Author : FLORIDA UNIV GAINESVILLE

Personal Author(s) : Whitney, E. D. ; Adair, James H. ; Holloway, Paul H. ; Mecholsky, John J., Jr. ; Winefordner, James D.

PDF Url : ADA336490

Report Date : 31 MAY 1997

Pagination or Media Count : 373

Abstract : A multidisciplinary team of investigators from the University of Florida, the University of Utah, and the University of Tennessee conducted a comprehensive, integrated study on the wear and fatigue of ceramic and metal materials for aerospace applications. The work was focused on a study of wear and fatigue in the context of the materials silicon nitride (Si3N4) and M-50 steel, and environments relevant to hybrid bearings in advanced turbine engines. The four year program was initiated in May, 1993 and concluded at the end of May, 1997. This document represents the fourth and final report of the program. A fundamental approach was employed to better understand the combined effects of mechanical stress, chemical environment, and high temperatures on wear and fatigue. Individual expertise on the research team spanned the disciplines of material science, chemistry, mechanics, and physics needed to understand the tribo-chemical nature of wear and fatigue. The program was also strongly coupled to industry and national laboratories to better facilitate transfer of the fundamental knowledge and technology to be developed into existing military and commercial systems. The primary objectives in the study were to: (1) develop and evaluate ex-situ and selected in-situ methods to detect wear; (2) develop a broad-based fundamental understanding of wear and wear mechanisms; (3) develop rolling contact fatigue maps for the hybrid bearing systems; (4) develop lifetime predictions for wear and rolling contact fatigue based on the ex-situ and in-situ wear detection methods; and (5) develop surface modification systems for hybrid bearing systems that either aid in wear detection or act to minimize wear damage.

Descriptors :   *WEAR, *FATIGUE(MECHANICS), *SILICON NITRIDES, DEGRADATION, STEEL, AEROSPACE SYSTEMS, CERAMIC MATERIALS, TURBINES, ANTIFRICTION BEARINGS.

Subject Categories : Ceramics, Refractories and Glass
      Properties of Metals and Alloys
      Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE