Experimental investigation of Zr-rich Zr–Zr₂Ni–(Zr,Ti)₂Ni ternary eutectic system

As potential substitutes for traditional Ti(Zr)–Cu–Ni-based brazing metals for high strength Ti alloys as well as a study for metallic glass, Zr–Ti–Ni-based alloys have been attracting much attention recently. In this study, the melting temperatures and microstructures of the Zr(Ti)-rich Zr–Ti–Ni alloys with Ni content below 33.3 at.% were systematically studied. A ternary deep eutectic alloy consisting of three phases was found at the composition of Zr₅₀Ti₂₆Ni₂₄ with a solidus temperature of 798 °C and a liquidus temperature of 809 °C, which are significantly lower than the Zr₂Ni–(Zr,Ti)₂Ni pseudobinary eutectic melting temperature of 850 °C. This ternary eutectic reaction can be presented as L → α-(Zr/Ti) solid solution + Zr₂Ni + ternary Laves (Zr,Ti)₂Ni.