Coarsening Behaviour of γ′ Precipitates in High Fe Containing Ni-Fe-Cr-Based Medium Entropy Alloy.

Present work evaluates coarsening kinetics of γ′ precipitates in γ–γ′-based microstructure of a high Fe-containing low-density low-cost Ni-29.8Fe-11.1Cr-3.7Al (wt pct) medium entropy alloy. The experimentally estimated mean size of the γ′ precipitates, during isothermal ageing of the alloy at 600 °C for varying duration, agrees well with the theoretical prediction by considering interfacial energy of 10 mJ/m². This investigation suggests the sluggish coarsening kinetics with diffusion of Cr across γ–γ′ interface as the rate controlling factor. [ABSTRACT FROM AUTHOR]