In this study, (Al_0.5CrFeNiTi_0.25)N_x high-entropy films are prepared by a reactive direct current (DC) magnetron sputtering at different N₂ flow rates on silicon wafers. It is found that the structure of (Al_0.5CrFeNiTi_0.25)N_x high-entropy films is amorphous, with x = 0. It transforms from amorphous to a face-centered-cubic (FCC) structure with the increase of nitrogen content, while the bulk Al_0.5CrFeNiTi_0.25 counterpart prepared by casting features a body-centered-cubic (BCC) phase structure. The phase formation can be explained by the atomic size difference (δ). Lacking nitrogen, δ is approximately 6.4% for the five metal elements, which is relatively large and might form a BCC or ordered-BCC structure, while the metallic elements in this alloy system all have a trend to form nitrides like TiN, CrN, AlN, and FeN. Therefore, nitride components are becoming very similar in size and structure and solve each other easily, thus, an FCC (Al-Cr-Fe-Ni-Ti)N solid solution forms. The calculated value of δ is approximately 23% for this multicomponent nitride solid solution. The (Al_0.5CrFeNiTi_0.25)N_x films achieve a pronounced hardness and a Young’s modulus of 21.45 GPa and 253.8 GPa, respectively, which is obviously much higher than that of the as-cast Al_0.5CrFeNiTi_0.25 bulk alloys.

Zr-Ti-Nb-Ta alloys were synthesized in parallel via multi-target co-sputtering deposition with physical masking in a pseudo-ternary Ti-Nb-ZrTa alloy system. Sixteen alloys with distinct compositions were obtained. Comprehensive characterization of phase structure, microstructure, Young’s modulus, and nanoindentation hardness was undertaken. The Ti-Nb-ZrTa alloys exhibited two typical phase structures: a single-BCC solid-solution structure, and an amorphous structure. Nanoindentation quantification confirmed a Young’s modulus ranging from 110 to 130 GPa, alongside nanoindentation hardness spanning 3.6 to 5.0 GPa. The combination of good hardness and a relatively low Young’s modulus renders these alloys promising candidates for excellent biomedical materials. This work not only offers an effective method for the high-throughput synthesis of multi-principal element alloys, but also sheds light on a strategy for screening the phase structure and mechanical performance within a given alloy system.