HiPIMS/DCMS复合磁控溅射(Al0.5CoCrFeNiTi)Nx薄膜结构及性能研究OA

As a more advanced surface modification technique,HiPIMS/DCMS hybrid magnetron sputtering fully leverages the synergistic advantages of the highly ionized plasma of HiPIMS(which enhances densification and interfacial adhesion of films)and the high deposition rate of DCMS(which ensures process efficiency)compared with individual HiPIMS or DCMS processes.In this study,an innovative method is employed with a high-power impulse power supply to sputter the Al0.5CoCrFeNi high-entropy alloy target,while a DC power supply is concurrently used to sputter the high-purity Ti target,so as to achieve precise control and efficient co-deposition of multiple metallic elements.By systematically adjusting the nitrogen flow ratio(RN2),the influence of reactive gas concentration on film composition evolution,crystalline structure transformation,and performance is thoroughly investigated.A SP-0606ASI magnetron sputtering vacuum coating system is employed for the hybrid deposition experiments.(Al0.5CoCrFeNiTi)Nx high-entropy nitride films are deposited on polished and cleaned GCr15 bearing steel and silicon wafer substrates at different nitrogen flow ratios(0,10%,20%,30%,and 40%by volume).During deposition,a Ti interlayer is first deposited at a constant current of 5 A for 10 minutes,followed by co-deposition of the functional(Al0.5CoCrFeNiTi)Nx high-entropy nitride layer via HiPIMS(constant power:1.5 kW,pulse width:40 μs,pulse frequency:25 000 Hz,deposition time:80 min)combined with DCMS(constant current:7 A,deposition time:80 min).Film microstructure and thickness are characterized by scanning electron microscopy(SEM),elemental composition at selected points is analyzed by energy-dispersive spectroscopy(EDS),and phase composition of the films is characterized by X-ray diffraction(XRD).Film hardness and elastic modulus are measured via nanoindentation(TI980).The electrochemical corrosion behavior of the films in a 3.5%NaCl solution is evaluated with a three-electrode system on a Princeton electrochemical workstation,and the electrochemical impedance spectra are fitted using Zview software.Nanocrystalline(Al0.5CoCrFeNiTi)Nx high-entropy nitride films are successfully fabricated on GCr15 bearing steel and silicon wafer substrates via HiPIMS/DCMS hybrid magnetron sputtering.With the introduction and increase of nitrogen,the films transition from an amorphous state to a nanocrystalline structure consisting of multiple nitride phases such as TiN and CrN.As the N2/(N2+Ar)ratio(RN2)increases,the atomic percentage of Al relative to the total high-entropy elements increases from 7.91%to 9.89%(gradually approaching the designed target composition),while the Ti proportion among metallic elements decreases from 47.62%to 36.14%.With the increasing RN2,film hardness(H)increases from 10.317 GPa to 22.7 GPa,while H/E and H3/E2 values increase simultaneously to 0.069 and 0.110 GPa,respectively.At RN2=40%,the hardness of the(Al0.5CoCrFeNiTi)N0.4 high-entropy nitride film is 119.967%higher than that of the Al0.5CoCrFeNiTi metallic film.At RN2=20%,the film exhibited optimal corrosion resistance:the corrosion potential increasing by 37.895%relative to the GCr15 substrate and by 18.146%compared with the nitrogen-free film,while the corrosion current density decreases by 68.091%and 58.514%,respectively.Simultaneously,its hardness(16.579 GPa)remains 60.696%higher than that of the nitrogen-free film.The introduction of nitrogen significantly improves both the hardness and corrosion resistance of(Al0.5CoCrFeNiTi)high-entropy alloy films.At the optimal nitrogen flow ratio(RN2=20%),the films exhibit the best corrosion performance along with excellent mechanical properties.Appropriate nitrogen incorporation not only enhances interfacial integrity but also effectively inhibits the penetration corrosive media.This study confirms that precise control of nitrogen flow can optimize the structure and performance of high-entropy nitride films,providing essential theoretical and technical guidance for the development of novel protective coatings suitable for harsh service environments.