Crystallization Behavior of a Ti-Zr Alloy with GH4169 Alloy Powder as an Additive Prepared via Low-Temperature Liquid-Phase Spark Plasma Sintering

Ti-Zr alloy blanks were successfully prepared by low-temperature liquid-phase sintering at 1000 °C using GH4169 alloy powder as an additive. Then, the crystallization and organization evolution laws of Ti-Zr alloy under different holding time conditions during the sintering process were studied in detail. Research shows that, when the holding time reached 30 min, the sintered alloy contained α-phase, β-phase, and titanium oxide phases. The average grain sizes of the α-phases and β-phases matrix are in the ranges of 100 to 300 nm and 50 to 80 μm, respectively. However, when the holding time was less than 20 min, the temperature gradient dropped greatly due to an instantaneous power failure during the spark plasma sintering process, which made it too late for the liquid phase at the grain boundaries to crystallize and caused the amorphous phase to form between them. Subsequently, the α-transition phase first precipitated and then, transformed into the β-phase. The α-transition phase mainly precipitated in the (123¯5)[55¯01] orientation, while the β-phase mainly precipitated in the (114¯)[11¯0] and 161⟨41¯2⟩ orientations, with the preferred orientation being 114[11¯0].