Liquidus projection of the Al–Ti–Zr system

• Published in: Journal of alloys and compounds 2020-12, Vol.849, p.156463, Article 156463
• Main Authors: Abreu, D.A., Silva, A.A.A.P., Santos, J.C.P., Barros, D.F., Barros, C.S., Chaia, N., Nunes, C.A., Coelho, G.C.
• Format: Article
• Language: English
• Subjects: Aerospace industry; Aluminum; Al–Ti–Zr system; Binary systems; Electric arc furnaces; Intermetallic compounds; Liquidus; Liquidus projection; Microstructural analysis; Microstructure; Phase diagram; Solidification; Ternary systems; Titanium aluminides; Titanium base alloys; Zirconium
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.156463

Phase equilibria in Al–Ti–Zr system has an important role for the development of lightweight materials aiming at their application in the aeronautical and aerospace industry. In order to improve the literature data related to this system, in the present work, its liquidus projection was experimentally determined based on microstructural analysis of twenty-seven alloys in the as-cast condition. Alloys were produced by melting high-purity elements in an arc furnace and their microstructures were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffractometry (XRD). Nine primary solidification regions were identified: β-BCC, γ-TiAl, ζ-Ti2+xAl5-x, ε(ht)-TiAl3, ZrAl3, ZrAl3, Zr2Al3, Zr5Al4 and Zr5Al3 while regions of primary precipitation of Zr3Al2, α-HCP and (Al) were proposed based on literature information of binary systems. Two ternary type I, seven ternary type II and one ternary type III invariant reactions are suggested and no ternary phase was observed. •Liquidus projection of the Al–Ti–Zr system is for the first time proposed.•Twenty seven arc-melted alloys were characterized by SEM/EDS and DRX.•The β–BCC primary solidification region is predominant in the liquidus projection.•No ternary compound was identified in the microstructures of the samples.