Viscous flow assisted sintering of AlCoCrFeNi high entropy alloy powder

[Display omitted] •This work studies the sintering mechanisms of AlCoCrFeNi HEA powder.•Activation energy of 166 ± 13 kJ/mol, was found to be in the range of reported literature data of similar alloys.•Formed viscous phase at higher temperature was found to be Cr-rich phase. Present investigation attempts to evaluate the sintering kinetics of mechanically alloyed AlCoCrFeNi high entropy alloy powder. Dilatometric study shows an accelerated densification above 1150 °C during non-isothermal sintering. The process was characterized with an activation energy of 166 ± 13 kJ/mol. Sintering was found to be controlled by the viscous flow mechanisms and atomic diffusion of constituent elements in the melt phase. This was attributed to the formation of some Cr-rich viscous phase, which had a good wettability on the solid. Results were further confirmed by an endothermic peak during differential scanning calorimetry and the solidified phases around the grains, in the quenched microstructure.