Isothermal corrosion （γ＇＋γ） Ni3Al alloy in liquid zinc

The isothermal corrosion testing and microscopic examination of Ni3Al alloy in liquid zinc containing small amounts of aluminum （mass fraction less than 0.2%） at 450℃ were carried out. The results show that the controlling mechanism of the dissolution reaction is diffusion through a boundary layer into liquid zinc. For two-phase alloy, Ni3Al alloy （γ＇＋γ）, the interface between dissolving solid and liquid remains remarkably planar and the difference in dissolution of the two adjacent phases （γ＇＋γ） can not be experimentally observed. The boundaries between y＇ phase and y phase play no perceptible role in the dissolution of Ni3Al alloy in liquid zinc. The X-ray diffi＇action spectra of the diffusion layer confirm the presence of Ni5Zn21. The corrosion rate of the Ni3Al alloy in molten zinc was calculated to be approximately 2.6×10^-3 g/（cm^2·h）, therefore the liquid zinc corrosion resistance of Ni3Al alloy is very weak.