Preparation of AlCoCrFeNiTi0.5 high entropy alloy by SPS from mechanically alloyed powders
Paper in proceedings, 2015
High entropy alloys are newly developed class of materials with excellent properties and promising application potential. The present work reports synthesis of inequiatomic alloy AlCoCrFeNiTi0.5 prepared by mechanical alloying (MA) in planetary ball mill followed by spark plasma sintering (SPS). Alloying behaviour, microstructure, basic mechanical properties and thermal behaviour of the alloy were investigated by means of XRD, SEM and DSC analyses and microhardness testing. It was found that the MA process parameters significantly influence homogeneity and size of the obtained alloyed powders. During MA, Cr-based supersaturated solid solution with body-centered cubic (BCC) structure was formed. After SPS at 1000°C the fine grained microstructure consisted of BCC solid solution and ordered FCC phase. Low levels of retained porosity were observed. The alloy exhibited a high hardness of 762HV.