The ultra-high-temperature creep behaviors of an Ir-base, Ir-23Nb (in at. pct), two-phase refractory superalloy have been investigated. The compression creep experiments were performed at tempera- tures from 1650°C to 1800°C at initial applied stresses from 49 to 200 MPa. The results show that Ir-23Nb alloy has higher creep resistance and longer creep life in comparison to Ir-17Nb alloy under the same experimental conditions. The steady-state creep behavior can be described in terms of power-law creep with the apparent stress exponent of 4.5 and apparent activation energy of 653 kJ/mol. Basing on the investigation, the possible reasons for the great improvement on the creep resistance and creep life in Ir-23Nb alloy are discussed.
|Number of pages||5|
|Journal||Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science|
|Publication status||Published - 2003 Oct|
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys