Effect of Aging Treatment on the Electrochemical and Corrosion Behavior of NiTiRe Shape Memory Alloy

摘要

In this study, Ni52Ti47.7Re0.3 shape memory alloy was subjected to solution treatment at 1000 C for24h (the tested alloy), followed by ageing at 300, 400, 500 and 600 C for 3h. The objective is toinvestigate the effect of ageing temperature on the uniform and pitting corrosion characteristics ofNi52Ti47.7Re0.3 alloy. Measurements were conducted in 1.0 M H2SO4 solutions without and with 0.2 MNH4F, using polarization, impedance, and chronoamperometry measurements. Morphologies of thecorroded surfaces were examined by SEM/EDX examinations. Results obtained from the employedelectrochemical techniques were in good agreement and showed that the rates of the uniform andpitting corrosion processes of the tested alloy decrease with increase in the aging temperature, reachingo their minimum values at an aging temperature of 400 C. Further increase in the aging temperature upo to 600 C led to an obvious increase in the rates of corrosion. Experimental finding were interpretedadopting the effect of the aging temperature on the microstructure of the tested alloy.