Experimental investigation of phase equilibria in the Al–Cr–Fe system. (September 2019)

• Record Type: Journal Article
• Authors: Rank, Maximilian; Franke, Peter; Hoffmann, Jan; Seifert, Hans J.
• Is Part Of: Calphad. Volume 66(2019)
• Publication Date: 2019-09
• Subjects: Phase diagram -- Al–Cr–Fe -- Ordering -- Thermal analysis; Phase diagrams -- Data processing -- Periodicals; Thermochemistry -- Data processing -- Periodicals; Diagrammes de phases -- Informatique -- Périodiques; Thermochimie -- Informatique -- Périodiques; Thermodynamica; Electronic journals; 541.363
• DOI: 10.1016/j.calphad.2019.101638
• Languages: English
• ISSNs: 0364-5916

Abstract

Abstract: The literature of the ternary Al–Cr–Fe system was evaluated and major open questions were identified. Transition temperatures between α-Fe, Al (A2) – FeAl (B2) and FeAl (B2) – Fe3 Al (D03 ) as well as solidus/liquidus temperatures in the Cr-rich corner were determined. The results from thermal analysis show a substantial decrease of the A2/B2 transition temperature with increasing Cr content at constant x(Al). Furthermore, a partial solidus and liquidus projection below 50 at.-% Al were created. Several partial isothermal sections have been studied with equilibrated alloys and diffusion couples. Therefore, complementary methods were used such as thermal analysis, electron microscopy, chemical analysis, X-ray powder diffraction and electron probe microanalysis. Equilibration experiments have been performed at 973 K, 1173 K, 1315 K, 1373 K and 1423 K and two partial isothermal sections at the two lowest temperatures were constructed indicating a solubility of 22 at.-% iron in the AlCr2 phase at 973 K. Highlights: A2/B2 transition temperatures decrease with increasing x(Cr) at constant x(Al). Liquidus and solidus projection below 50 at.-% of Al. Good agreement between diffusion couples and equilibration annealing. Partial isothermal sections at 973 K and 1173 K. Solubility of Fe in AlCr2 at 973 K was found to be ∼ 22 at.-%.