The corrosion behavior of the Ni3Al intermetallic materials obtained by SPS in alkali solutions

Abstract The effect of boron additives on the corrosion resistance of Ni3Al intermetallic obtained by spark plasma sintering of powder mixtures with preliminary mechanical activation in alkali water is studied. It is established that monophasic nickel aluminide and alloyed with 0.1% B has high corrosion resistance in boiling solutions of strong alkalis, such as potassium and sodium hydrate. The corrosion rate in such medium is less than 0.05 mm/year, even when corrosion activators are added into the solution. High corrosion resistance is due to the processes of passivation of the material during the interaction of the surface of the material with the solution. Solutions of weak alkalis have a more aggressive effect on sintered nickel aluminide. It is shown that the corrosion rate of intermetallic in aqueous ammonia is 0.22…0.24 mm/year. With the boron addition, the corrosion rate increased to 0.29 mm/year.