Some intermetallic compounds such as Nickel aluminides have been chosen as potential high temperature materials for aerospace industry in the last few decades. One of the main nickel aluminide compounds is NiAl. Recently, attempts for improving the performance of NiAl intermetallic have led to the modifications of this phase by adding some elements. In this research a comparative study has been made on the corrosion behavior of NiAl and Ni2AlSi phases. For this purpose, NiAl and Ni2AlSi intermetallic compounds were successfully synthesized by mechanical alloying and the obtained powders were consolidated using spark plasma sintering process. X-ray diffraction analysis and field emission scanning electron microscopy were used for phase evolutions and morphological characterization of the corroded samples, respectively. Mechanical alloying of binary system led to the formation of NiAl intermetallic compound, while in ternary system, Ni2AlSi ternary intermetallic compound was formed after 30 h of mechanical alloying. It was observed that Ni2AlSi sample has much less current density (about 10 times) as compared with NiAl sample, indicating lower corrosion rate of this sample. The results showed that the surface of Ni2AlSi sample is smoother and has lower porosity as compared with NiAl sample.
