A study of thermal stability in electrodeposited nanocrystalline Fe-Ni invar alloy

► Thermal stability and grain growth kinetics of a NC Fe-Ni invar alloy were studied. ► The alloy showed good stability to 0.36Tm and abrupt grain growth happened above that. ► The activation energies indicated different growth mechanisms below and above 0.36Tm. ► Below 0.36Tm, grain boundary re-ordering may act as the grain growth mechanism. ► Above 0.36Tm, grain boundary diffusion may act as the grain growth mechanism.