Ultrahigh strengthening effect induced by element addition in nanostructural (TiVCr)100−xWx medium entropy alloy

•DC magnetron co-sputtering technology was performed to synthesize (TiVCr)100−xWx alloy films.•Doping W into TiVCr alloys film induces a phase transition from amorphous to quasicrystal and nanocrystal.•An ultrahigh strengthening effect where the strength is enhanced by two times was observed. In this work, we have investigated the effect of W addition on microstructure and mechanical properties of equiatomic TiVCr medium entropy alloy films. It is found that a transition from amorphous phase to quasicrystal and nanocrystal occurs with increasing content of W, showing an improved crystallinity of the films. Hardness drastically increases with increasing W addition and reaches the maximum value of 7.2 GPa at 16.0 at% W content, which is two times higher than that of the initial sample. Amorphous phase strengthening, solid solution and precipitation strengthening become the dominant mechanism, responsible for the ultrahigh strengthening effect.