Verifying the Effects of SIMA (Strain Induced Melt Activation) Process on Corrosion Behavior in Al Sacrificial Anodes

Abstract The Strain Induced Melt Activation (SIMA) process is one of the semi-solid forming processes in Preparation of non-dendritic microstructurs. In this research¡ verifying the effects of SIMA process on microstructure and the corrosion behavior of Al-Zn-In sacrificial anode was studied. The effect of plastic deformation on the semisolid microstructure of Al-Zn-In alloy was investigated by applying 10-40% uniaxial compression at the ambient temperature and the semi-solid treatment was carried out at the range of 640 to 660 C for 40 min. Investigate the behavior corrosion by Tafel polarization test was performed in a solution of Sodium Chloride 3.5%. The results indicated that the microstructure of SIMA processed specimens is finer and more Globular than the microstructure of initial material. With increase in the compression ratio from 10 to 30%¡ The sphericity increased significantly but the variation rate of the average grain size increased and the shape factor decreased with more increase in the compression ratio up to 40%. The average size and sphericity of ?-Al solid grains increased with the increase of the temperature heat treatment. Tafel test results showed¡ Corrosion potential samples alloys Al-Zn-In is more negative and lowest rate of corrosion related to sample heat treated at 640 C with the compression ratio 30%. The results of scanning electron microscopy also indicate the uniform corrosion under aforementioned conditions.