Effect of W and Zr on structural, thermal and magnetic properties of AlCoCrCuFeNi high entropy alloy

The equiatomic multicomponent AlCoCrCuFeNi hexanery high entropy alloy (HEA) was synthesized by mechanical alloying. The effect of the addition of W and Zr was studied by making equiatomic AlCoCrCuFeNiW septenary and AlCoCrCuFeNiWZr octonary high entropy alloys. The effect of alloying addition with milling time was studied using XRD, DSC/TGA, SEM, TEM and Mossbauer spectroscopy. Supersaturated solid solution structure was achieved after 60 h milling for hexanery alloy and after 40 h milling for both septenary and octonary high entropy alloys. The variation of Mossbauer parameters for AlCoCrCuFeNi system with the addition of W and Zr makes its magnetic environment more complex which is indicated by the conversion of magnetic AlCoCrCuFeNi HEA (60 h milling) to partially paramagnetic AlCoCrCuFeNiW (40 h milling) to completely paramagnetic AlCoCrCuFeNiWZr high entropy alloy. (C) 2012 Elsevier B. V. All rights reserved.