Capillarity interaction of NiTi melt with crucible oxides

The interaction of nitinol melt with Al2O3, ZrO2, BeO and Y2O3 oxides used as crucible materials has been studied. Capillary interaction has been monitored directly using the method of sessile drop with video and thermal imaging in 10−3torr vacuum at 1350 °C. Nitinol melt drops have been formed in a high-density graphite dispenseror directly on the substrate surface. The contact angleson the surface of polished oxides have been obtained. The contact angles established within 30 s increase in the sequence Al2O3, ZrO2, BeO and Y2O3 from 30° to 70°. The corrosion resistance of the oxides has been studied for cross-sections using scanning electron microscopy with energy dispersion analysis. The phase composition at the ceramic/melt boundary has been studied using transmission electron microscopy. Thermodynamic analysis of melt chemical interaction with oxides has been conducted within equilibrium concentration calculation. •The interaction of Nitinol melt with Al2O3, ZrO2, BeO and Y2O3 oxides crucible.•The contact angles increase in the sequence Al2O3, ZrO2, BeO and Y2O3.•The order of change in the contact angles was Y2O3 70о; BeO 62о;ZrO2 53о; Al2O3 30о.•This order is inverse to that of reaction constants of metal reduction from oxides by titanium.•The low contact angles of nitinol on Al2O3, BeO and ZrO2(Y) allow this melt to be recommended as solder at above 1310 °C.