Abstract
Refractory metal intermetallic composites (RMICs) based on the Nb-Ti-Si-Cr-Hf quinary are candidate materials for ultra-high temperature applications beyond 1200 °C. In this investigation, minor additions of Al, B, Y and Mo were introduced into the Nb-22Ti-(15-18)Si-6Cr-4Hf (at.%) base alloy for potential enhancement of the mechanical and environmental properties. The phases, phase compositions and morphologies in the as-cast microstructure of the base alloy with or without minor Al, B, Y and Mo additions were investigated using X-ray diffraction (XRD), optical metallography (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectrum (EDS) and electron probe microanalysis (EPMA). The experimental results obtained from several selected alloys were found to agree with the solidification paths calculated from the Scheil model using established thermodynamic properties of all the phases in the Nb-Ti-Si-Cr-Hf-Al system.
| Original language | English |
|---|---|
| Pages (from-to) | 992-997 |
| Number of pages | 6 |
| Journal | Intermetallics |
| Volume | 18 |
| Issue number | 5 |
| DOIs | |
| State | Published - May 2010 |
| Externally published | Yes |
Funding
The authors would like to thank CompuTherm LLC for their support of using Pandat program and the database. This work was financially supported by the National Natural Science Foundation of China under the grant of No. 50671081 and the fund of the State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, China under the grant No. 07-TP-2008.
| Funders | Funder number |
|---|---|
| National Natural Science Foundation of China | 50671081 |
| Northwestern Polytechnical University | 07-TP-2008 |
| State Key Laboratory of Solidification Processing |
Keywords
- A. Intermetallics, miscellaneous
- A. Silicides, various
- B. Thermodynamic and thermochemical properties
- C. Casting
- D. Microstructure