Glass formation of Ti–Ni–Sn ternary alloys correlated with TiNi–Ti3Sn pseudo binary eutectics

Glass-forming ability (GFA) of Ti–Ni–Sn ternary alloys was investigated. Applying recent models based on atomic size ratio and efficient packing, the composition favoring the glass formation is predicted. Our experiments indicate that the optimized glass-forming composition is located at Ti56Ni38Sn6, with the critical thickness of complete glass formation approaching 100 μm for the melt-spun ribbons. The Ti56Ni38Sn6 metallic glass exhibits a sizable supercooled liquid region (ΔTx) of about 35 K and a reduced glass transition temperature (Trg) of 0.52. We demonstrate that the glass formation of the Ti56Ni38Sn6 alloy correlates with the (L → TiNi + Ti3Sn) pseudo binary eutectic reaction in Ti–Ni–Sn ternary system, which has an invariant temperature and composition at ∼1370 K and ∼Ti58Ni34Sn8, respectively. With respect to Sn-free Ti–Ni binary alloys, the GFA is enhanced for the Ti–Ni–Sn ternary alloys, but the improvement is limited possibly due to changes in the crystalline phases competing with glass formation.