In this study, Al0.5CoCrFe1.5NiTi0.5 high-entropy alloy was heat-treated from 500 °C to 1200 for 24 h investigate age-hardening phenomena and microstructure evolution. The as-cast alloy, with a hardness of HV430, exhibited dendritic structure comprising an (Fe,Cr)-rich FCC phase (Ni,Al,Ti)-rich B2 phase, the interdendrite spinodal decomposed BCC phase. Age hardening softening occurred at 800 90...