Accession Number:

ADA504052

Title:

Influence of Residual Stresses on Fretting Fatigue Life Prediction in Ti-6Al-4V (POSTPRINT)

Descriptive Note:

Journal article postprint

Corporate Author:

AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE

Report Date:

2008-01-01

Pagination or Media Count:

14.0

Abstract:

The objective of this work was to evaluate life prediction methodologies involving fretting fatigue of turbine engine materials with advanced surface treatments. Fretting fatigue tests were performed on Ti-6Al-4V dovetail specimens with and without advanced surface treatments. These tests were representative of the conditions found in a turbine engine blade to disk attachment. Laser shock processing and low plasticity burnishing have been shown to produce deep compressive residual stresses with relatively little cold work. Testing showed these advanced surface treatments improved fretting fatigue strength by approximately 50 . In addition to advanced surface treatments, several specimens were also coated with diamond-like carbon applied through a nonline-of-sight process capable of coating small dovetail slots in an engine disk. Testing with this coating alone and combined with advanced surface treatments also significantly improved fretting fatigue strength due to a decreased coefficient of friction along with the compressive residual stresses.

Subject Categories:

  • Coatings, Colorants and Finishes
  • Properties of Metals and Alloys
  • Test Facilities, Equipment and Methods
  • Mechanics
  • Logistics, Military Facilities and Supplies

Distribution Statement:

APPROVED FOR PUBLIC RELEASE