Study On The Corrosion Behavior Of Fe-based And Cu-based Shape Memory Alloy

Shape memory alloy is getting more people's attention as a new function material with its particular shape memory effects and super-elasticity. With the wide application of Fe-based and Cu-base SMA, Lack of basic corrosion data is one of the factors hindering the research and development of SMA. The thesis tried to discuss the crevice and galvanic corrosion of FeMnSi SMA tube coupling, and the relationship between corrosion resistance and phase transformation so as to lay foundations of further engineering application.Electrochemical Impedance method was used to study the crevice corrosion of FeMnSi SMA. The research discovered that the polarized resistance Rp inside crevice was smaller than outside, and increases with the immersing time for both. The traditional galvanic corrosion method is used for monitoring the galvanic corrosion of Fe-based SMA tube coupling and the tube. The result revealed that the galvanic current density and the area ratio of the cathode to the anode does not obey the logarithmic proportional relation. Long time immersing test was taken to study the corrosion resistance of Fe-based SMA. The test revealed that the polarization resistance Rp decreases with the prolonging of immersing time.As for the CuZnAl SMA, we acquired the temperature dependence of open circuit potential, and test the electrochemical Impedance spectra at special temperature, in order to find the relation between corrosion resistance and phase transformation.