摘要
In this study, magnetron sputtering was utilized to deposit Ni30Co30Fe13Cr15Al6Ti6 high-entropy alloy thin films (HEAFs) at various substrate temperatures, ranging from 25 °C to 400 °C. When the substrate temperature is below 200 °C, the HEAFs show columnar structure with nearly 100 % (111)-oriented face-centered cubic (FCC) phases. The growth nanotwins are also observed with an average twin thickness below 2 nm. When the substrate temperature exceeds 200 °C, the columnar structure gradually transforms into a dual-phase body-centered cubic (BCC)+FCC polycrystalline structure accompanying the disappearance of nanotwins. The nanotwinned HEAFs deposited at below 200 °C exhibit high hardness (> 10.5 GPa) and low roughness (Rms < 0.58 nm). When the substrate temperature exceeds 200 °C, the hardness of HEAFs decreases and the roughness becomes higher. The residual stress also shifted from compressive stress to tensile stress with rising substrate temperatures.
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•Effect of substrate temperature on nanotwin formation and properties of HEA films.•Nanotwins form in highly (111)-oriented FCC phase when temperature below 200 °C.•Dual BCC and FCC phases with no twins when deposited temperature exceeds 200 °C.•Nanotwinned HEAFs exhibit high hardness (> 10.5 GPa) and low roughness (Rms < 0.58 nm).