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A new type of high-entropy alloy, a nitride-based (AlCrTiZrMo)N/ZrO2 nano-multilayered film, was designed to investigate the effect of ZrO2 layer thickness on the microstructure, mechanical properties, and thermal stability. The results show that when the thickness of the ZrO2 layer is less than 0.6 nm, it can be transformed into cubic-phase growth under the template effect of the (AlCrTiZrMo)N layer, resulting in an increased hardness. The (AlCrTiZrMo)N/ZrO2 film with a ZrO2 layer thickness of 0.6 nm has the highest hardness and elastic modulus of 35.1 GPa and 376.4 GPa, respectively. As the thickness of the ZrO2 layer further increases, ZrO2 cannot maintain the cubic structure, and the epitaxial growth interface is destroyed, resulting in a decrease in hardness. High-temperature annealing treatments indicate that the mechanical properties of the film decrease slightly after annealing at less than 900 °C for 30 min, while the mechanical properties decrease significantly after annealing for 30 min at 1000–1100 °C. The hardness and elastic modulus after annealing at 900 °C are still 24.5 GPa and 262.3 GPa, showing excellent thermal stability. This conclusion verifies the “template” effect of the nano-multilayered film, which improves the hardness and thermal stability of the high-entropy alloy. 

A series of (AlCrTiZrV)-Six-N films with different silicon contents were deposited on monocrystalline silicon substrates by direct-current (DC) magnetron sputtering. The films were characterized by the X-ray diffractometry (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and nano-indentation techniques. The effects of the silicon content on the microstructures and mechanical properties of the films were investigated. The experimental results show that the (AlCrTiZrV)N films grow in columnar grains and present a (200) preferential growth orientation. The addition of the silicon element leads to the disappearance of the (200) peak, and the grain refinement of the (AlCrTiZrV)-Six-N films. Meanwhile, the reticular amorphous phase is formed, thus developing the nanocomposite structure with the nanocrystalline structures encapsulated by the amorphous phase. With the increase of the silicon content, the mechanical properties first increase and then decrease. The maximal hardness and modulus of the film reach 34.3 GPa and 301.5 GPa, respectively, with the silicon content (x) of 8% (volume percent). The strengthening effect of the (AlCrTiZrV)-Six-N film can be mainly attributed to the formation of the nanocomposite structure.