Microstructural and Phase Changes in TiNi Alloy after Electrochemical Corrosion Tests

In the presented paper, complex studies of microstructure and phase composition of the alloy before and after electrochemical corrosion tests in solutions of 1 M HCl, 3 M HCl, 1 M H₂SO₄, and 3 M H₂SO₄ have been carried out. The studies showed that the corrosion process in the alloy Ti_49.1Ni_50.9 in the case of electrochemical corrosion took place on all samples and in all solutions in the form of appearance of pittings, as well as with corrosion products when tested in H₂SO₄ solutions with different concentrations; in the case of 3 M HCl, corrosion products were also found on the surface of the samples. A change in character of the microstructure was found in the coarse grained state in 3 M solutions, while no such change was found in the ultrafine grained state.