Surface effects on the mechanical properties of gamma titanium aluminides

Research output: Contribution to book/Conference proceedings/Anthology/ReportConference contributionContributedpeer-review

Contributors

  • Janny Lindemann - , Brandenburg University of Technology Cottbus-Senftenberg (Author)
  • Maria Glavatskikh - , Brandenburg University of Technology Cottbus-Senftenberg (Author)
  • Christoph Leyens - , Institute of Materials Science, Chair of Materials Technology, TUD Dresden University of Technology (Author)

Abstract

Surface conditions are of significant importance for the fatigue performance of rotating components for aircraft and automotive applications. Compared to the electropolished reference state the fatigue performance of gamma titanium aluminides at ambient temperature can be significantly improved by shot peening, while the fatigue strength after roller burnishing is hardly affected. Fatigue strength improvements after shot peening are mainly caused by cyclically stable residual compressive stresses in the near-surface region. Notably, also conventional turning operations generate high dislocation densities and residual compressive stresses in the near-surface region resulting in fatigue strength improvements similar to shot peening. Surface strengthening by shot peening or machining leads to subsurface fatigue crack nucleation and overcompensates the detrimental influence of the high surface roughness on fatigue. However, for temperatures above 650 °C, residual compressive stresses induced by shot peening and machining quickly relax. This indicates that, at elevated temperatures, surface roughness and dislocation strengthening become increasingly important for the fatigue performance of components.

Details

Original languageEnglish
Title of host publicationTHERMEC 2011
PublisherTrans Tech Publications Ltd
Pages1071-1076
Number of pages6
ISBN (print)9783037853030
Publication statusPublished - 2012
Peer-reviewedYes

Publication series

SeriesMaterials Science Forum
Volume706-709
ISSN0255-5476

Conference

Title7th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC'2011
Duration1 - 5 August 2011
CityQuebec City, QC
CountryCanada

Keywords

Keywords

  • Gamma titanium aluminides, High cycle fatigue, Roller burnishing, Shot peening