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

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.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 2008
Accession Number
ADA504052

Entities

People

  • Dennis Buchanan
  • Patrick J. Golden
  • Sam Naboulsi

Organizations

  • Air Force Research Laboratory

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Force
  • Air Force Research Laboratories
  • Fatigue Life
  • Fatigue Tests (Mechanics)
  • Finite Element Analysis
  • Fracture (Mechanics)
  • Materials
  • Materials Science
  • Mechanical Working
  • Mechanics
  • Residual Stress
  • Shot Peening
  • Stress Strain Relations
  • Stresses
  • Surface Finishing
  • Tensile Strength
  • Turbines

Fields of Study

  • Materials science

Readers

  • Powder metallurgy of Titanium alloys.
  • Structural Health Monitoring of Composite Structures.

Technology Areas

  • Directed Energy