Crack Initiation in a Coated and an Uncoated Nickel-Base Superalloy Under TMF Conditions PUBLIC ACCESS

[+] Author Affiliations
Peter K. Johnson, María Arana, Koldo M. Ostolaza, Johan Bressers

Institute for Advanced Materials, Joint Research Centre, European Commission, Petten, The Netherlands

Paper No. 97-GT-236, pp. V004T14A046; 6 pages
  • ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition
  • Volume 4: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education; IGTI Scholar Award
  • Orlando, Florida, USA, June 2–5, 1997
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 978-0-7918-7871-2
  • Copyright © 1997 by ASME


A thermomechanical fatigue (TMF) cycle, intended to represent aero-engine blade working conditions, was selected for carrying out tests on uncoated and aluminide coated SRR99 samples until test piece failure. Optical images of the surface of test pieces were collected during testing to monitor surface crack initiation and accompanying transformations. Using these images, surface changes were quantified as a function of time. Post test, each sample was taken through an incremental polishing procedure to allow damage in the tested material to be studied as a function of depth, using optical microscope based quantitative metallography and scanning electron microscopy (SEM). The relationship between the observed surface changes and the damage built-up subsurface was examined. Differences in damage density on the surface and subsurface planes between coated and uncoated samples could accommodate the observed life reductions.

Copyright © 1997 by ASME
This article is only available in the PDF format.



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In