Corrosion Behavior of V2AlC and Cr2AlC in 0.01 N Calcium Hydroxide at Four Temperatures

Corrosion behavior of V2AlC and Cr2AlC materials have been investigated in 0.01N Ca(OH)2 at pH=11.7 using Potentiostat to estimate corrosion parameters. The results show that V2AlC material has more noble potential and lower current density than Cr2AlC over temperatures include 303, 313, 323 and 333K. Polarization resistance which calculated according to Stern-Geary equation confirms the most resistance for V2AlC in experimental conditions. The change in free energy was more negative for Cr2AlC than V2AlC, this means that V2AlC has less ability to corrosion. The negative value of ΔS for V2AlC confirms the later result. It`s known that corrosion rate depends on the value of the activation energy which is represents the energy maxima of intermediate transition states through which the entity must pass in transforming and the energy that must be acquired, from Arrhenius plots have been conducted that activation energy Ea for V2AlC was more than for Cr2AlC.