Corrosion behaviour of Cu-based shape memory alloys, diffusion bonded

The metallographic characterization and the corrosion resistance of diffusion bonded Cu-Al-Ag shape memory alloys was performed. An electrochemical study was performed, aimed at the evaluation of corrosion parameters both of the Cu-based alloy and the diffusion bonded alloy, using potentiodynamic techniques (ASTM standard G69-81). The polarisation curves were obtained in aerated marine water (3.5% NaCl solution). The result obtained indicates that bonded alloys exhibit low corrosion potential, inferior to that of Cu-Al-Ag alloys. The corrosion resistance of the bonded zone is worse than in the base material, due to the microsegregation occurring within the interphase bond, during the welding process.