Effect of Specimen Thickness on the Creep Response of a Ni-Based Single Crystal Superalloy (PREPRINT)
Abstract
Creep tests on Ni-based single crystal superalloy sheet specimens typically show greater creep strain rates and/or reduced strain or time to creep rupture for thinner specimens than predicted by current theories which predict a size independent creep strain rate and creep rupture strain. This size dependent creep response is termed the thickness debit effect. To investigate the mechanism of the thickness debit effect, isothermal, constant nominal stress creep tests were performed on uncoated PWA1484 Ni-based single crystal superalloy sheet specimens of thicknesses 3.18mm and 0.51mm under two test conditions: 760◦C/758MPa and 982◦C/248MPa. The specimens contained initial micro-voids formed during the solidification and homogenization processes. The dependence of the creep response on specimen thickness differed under the two test conditions: at 760◦C/758MPa there was a reduction in the creep strain and the time to rupture with decreasing section thickness while at 982◦C/248MPa a decreased thickness resulted in an increased creep rate even at low strain levels and a decreased time to rupture but with no systematic dependence of the creep.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 2012
- Accession Number
- ADA565889
Entities
People
- A. Needleman
- A. Staroselsky
- Ashok Srivastava
- R. Banerjee
- S. Gopagoni
- V. Seetharaman
Organizations
- University of North Texas