Effect of Mn on corrosion and thermal behaviour of AlCr1.5CuFeNi2Mnx high-entropy alloys

Abstract

There are numerous multicomponent alloys reported in the past resulting in a single phase with promising mechanical properties at high temperature. However, investigation on the corrosion properties and thermal conductivity of the novel high-entropy alloy (HEAs) are yet to be explored. The present study focuses on the effect of Mn on the corrosion and thermal behaviour of AlCr1.5CuFeNi2Mnx (x = 0, 0.25, 0.5, 0.75,1 in molar ratio) HEAs. The HEAs reported so far are mostly fabricated by arc melting process whereas, in this study, AlCr1.5CuFeNi2Mnx HEAs ingots were cast by high temperature vacuum induction furnace under inert gas environment. The electrochemical-corrosion behaviour of the as-cast alloys was studied using a potentiodynamic-polarization method immersed in 3.5 wt. %NaCl solution (open to air) at room temperature. It was observed from the polarization curve that the corrosion resistance was found to increase on the addition of higher amount of Mn in base alloy. The thermal conductivity of the HEAs was determined at 300 K, 350 K, 400 K, 450 K and 500 K. It was found that the thermal conductivity of the alloys decreases with the addition of the Mn content whereas the thermal conductivity is found to increase with the increase in the temperature of the alloys.