Abstract
A new metastable A15 phase in the Cr-Re system is predicted based on full-potential linear muffin-tin orbital (FLMTO) calculations of its electronic structure and cohesive properties. While A15 Cr 3Re is unstable as a bulk compound, we demonstrate that nonstoichiometry and carbon impurities play a dominant role in stabilizing this phase and may lead to the occurrence of A 15 type particles in Cr-based alloys. Thus, these A15 precipitates may scavenge carbon impurities and prevent the formation of brittle carbides and, additionally, provide an obstacle for dislocation motion. The formation of small close-packed particles appear to explain the improvement of both ductility and strength and is most likely the mechanism of the "rhenium effect" in Cr (W, Mo) based alloys.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2471-2476 |
| Number of pages | 6 |
| Journal | Acta Materialia |
| Volume | 50 |
| Issue number | 10 |
| DOIs | |
| State | Published - Jun 12 2002 |
Funding
We thank Professor M. Fine for encouragement and stimulating discussions. Work at Northwestern University was supported by the Air Force Office of Scientific Research (Grant No. F49620-01-1-0166) and, in part, by the Russian Basic Research Foundation (Grant No. 00-02-16086).
Keywords
- Ab initio calculation
- Chromium alloys
- Mechanical properties
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys