Abstract
The microstructure and the fracture of the new developed Ir-Nb-Ni-Al and Ir-Ta-Ni-Al were investigated. At 1300°C, three-phase equilibrium-fcc, L12-Ni3Al and Ir3Nb were observed in alloys Ir-5Nb-62.4Ni-12.6Al, Ir-15Nb-20.8Ni-4.2Al and three-phase equilibrium-fcc, L12-Ni3Al and Ir3Ta existed in alloys Ir-3.75Ta-62.4Ni-12.6Al and Ir-11.25Ta-20.8Ni-4.2Al; four-equilibrium-fcc, B2-IrAl, L12-Ni3Al and Ir3Nb or Ir3Ta were observed in alloy Ir-10Nb-41.6Ni-8.4Al or Ir-7.5Ta-41.6Ni-8.4Al. At 1400°C, the three-phase equilibrium existed in all of the alloys. The compressive strengths at 1200°C were from 79 to 616 MPa. The compressive strain of the quaternary was greatly improved compared with Ir-based alloys (below 10%). The lowest one was 18. The precipitation hardening of quaternary alloys can be caused by the precipitate-shearing mechanism. The compressive strength of quaternary alloys can be attributed to the precipitation and solid solution hardening as well as to the interface strengthening.
| Original language | English |
|---|---|
| Pages (from-to) | 677-684 |
| Number of pages | 8 |
| Journal | Key Engineering Materials |
| Volume | 171-174 |
| Publication status | Published - 2000 Jan 1 |
| Externally published | Yes |
| Event | Proceedings of the 1999 8th International Conference on Creep and Fracture of Engineering Materials and Structures - Tsukuba, Jpn Duration: 1999 Nov 1 → 1999 Nov 5 |
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering