Enhanced strength without sacrificing ductility in FeCrMnVSix high entropy alloys via controlling the ratio of metallic to covalent bonding

•The ELF and DOS calculations confirm that the orbitals of Si and FeCrMnV overlap and thus form covalent bonds.•Computational and experimental results show that addition of Si enhances the elasticity and hardness of FeCrMnVSixHEAs.•FeCrMnVSix HEAs have enhanced strength without sacrificing ductility due to the covalent bonding created by the Si atoms.•The Si-containing HEAs coatings exhibited excellent tribological properties.•Covalent bonding contributes to strength and metallic bonding facilitates ductility.