Ir-base refractory superalloys for ultra-high temperatures
- National Research Inst. for Metals, Ibaraki (Japan)
- Furuya Metals Co. Ltd., Ibaraki (Japan)
The microstructure and compression strengths of Ir-15 at. pct X (X = Ti, Ta, Nb, Hf, Zr, or V) binary alloys at temperatures between room temperature and 1,800 C were investigated to evaluate the potential of these alloys for ultra-high-temperature use. The fcc and L1{sub 2} two-phase structures of these alloys were examined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The strengths of the Ir-Ta, -Nb, -Hf, and -Zr alloys were above 800 MPa at temperatures up to 1,200 C and about 200 MPa at 1,800 C. The strengths of these alloys under 1,000 C are equivalent to or higher than those of the commercially used Ni-base superalloys, MAR-M247 and CMSX-10. The Nb concentration dependence of strength was investigated using a series of Ir-Nb alloys with Nb concentrations from 0 to 25 at. pct. It was found that the Ir-base alloys were strengthened by L1{sub 2} precipitation hardening. The potential of the Ir-base alloys for ultra-high temperature use is discussed.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 611585
- Journal Information:
- Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 2 Vol. 29; ISSN MMTAEB; ISSN 1073-5623
- Country of Publication:
- United States
- Language:
- English
Similar Records
Development of Ir-base refractory superalloys
Platinum group metals base refractory superalloys