Tribological and mechanical properties of surface nanocomposite AlCoCrFeNi2.1 high-entropy alloy produced by FSP

•The initial AlCoCrFeNi2.1 high entropy alloy possess eutectic structure consisting BCC/B2 phases and FCC/L12 phases.•The hardness and shear strength of the nanocomposite produced by FSP are significantly higher than that of the initial case.•After FSP, a great extent of grain refinement occurs due to the dynamic recrystallization (DRX) as well as the Zener effect.•The addition of TiO2 nanoparticles using FSP, reduces the wear resistance of high entropy alloy AlCoCrFeNi2.1.