Effect of the addition of Mg, Ti, Ni on the decoloration performance of AlCrFeMn high entropy alloy

Due to the excellent mechanical properties of high entropy alloys (HEAs), they have attracted wide attention of materials researchers, but their functional properties have rarely been reported. In order to study the functional properties of HEAs, the decoloration of azo dye Direct Blue 6 (DB6) using equiatomic AlCrFeMn and AlCrFeMnM (M= Mg, Ti, Ni) HEAs synthesized by mechanical alloying was reported in this work. The decoloration rate of DB6 by ball-milled (BM) AlCrFeMn was about 3 times faster than that of by BM MgZn-based amorphous alloy, which was the best one reported in the metallic glasses so far. In order to further improve the decoloration efficiency, we considered adding the fifth elements (Mg or Ti or Ni) to AlCrFeMn. Both of Mg and Ti could improve the decoloration performance of AlCrFeMn, but Ni played a negative role. The reaction activity of AlCrFeMnMg and AlCrFeMnTi was more than 2 and 1.2 times faster than that of AlCrFeMn. The effects of initial pH, temperatures and dye concentration on the decoloration efficiency of AlCrFeMnMg during reactions were systematically investigated. The reaction activity of AlCrFeMnMg in alkaline and acidic azo dye solution was about 37.5 and 16.6 times faster than that of neutral solution, respectively. This work had implications in reaching an attractive, low cost and efficient method for functional applications of HEAs. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.