Reaction Scheme and Liquidus Surface in the Al-Rich Section of the Al-Cr-Ni System

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Vol. 39; no. 10; pp. 2363 - 2369
• Main Authors: Weitzer, Franz, Xiong, Wei, Krendelsberger, Nataliya, Liu, Shuhong, Du, Yong, Schuster, Julius C.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.10.2008; Springer; Springer Nature B.V
• Subjects: Alloys; Applied sciences; Binary system; Characterization and Evaluation of Materials; Chemical reactions; Chemistry and Materials Science; Electron microscopes; Equilibrium; Exact sciences and technology; Liquids; Materials Science; Metallic Materials; Metals. Metallurgy; Nanotechnology; Solid solutions; Structural Materials; Surfaces and Interfaces; Thin Films; Ni2Al3; Differential Thermal Analysis Experiment; NiAl; Differential Thermal Analysis; Invariant Reaction
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-008-9579-1

The constitution of the ternary system Al-Cr-Ni is investigated over the entire composition range using X-ray diffraction (XRD), energy dispersive X-ray analysis (EDXA), differential thermal analysis (DTA) up to 1500 °C, and metallography. The ternary phase τ 1 is confirmed. Its crystal structure, homogeneity range, and melting temperature are corroborated. Two additional ternary phases, labeled τ 2 and τ 3 , are stable at 700 °C. Their compositions are Al 77.5 Cr 12.5 Ni 10 and Al 80 Cr 15 Ni 5 , respectively. Their XRD powder patterns are shown. The isothermal section at 700 °C and the reaction scheme linking it with the liquidus surface are presented. The Al-rich part of the liquidus surface is characterized by an eutectic trough, which descends monotonously from the pseudobinary maximum e max1 : L  = NiAl + (Cr) at 1433 ± 1 °C through a series of transition reactions and ends in the ternary eutectic E 2 : L  = Cr 7 Al 45  + NiAl 3  + (Al) at 639 °C.