氮气流量比对三靶高功率脉冲磁控共溅射(TiSiAlCrV)N薄膜结构和性能的影响OA

High-entropy alloy films exhibit high hardness,excellent wear resistance,and corrosion resistance.Magnetron sputtering is usually used to fabricate high-entropy alloy films,especially for the preparation of high-entropy alloy nitride films by reactive sputtering.Magnetron sputtering can be divided into direct-current magnetron sputtering(DCMS),radio-frequency magnetron sputtering(RFMS),and high-power impulse magnetron sputtering(HiPIMS),etc.According to the number of targets,magnetron sputtering can be divided into single-target magnetron sputtering and multi-target magnetron co-sputtering.Compared with single-target sputtering,multi-target co-sputtering can improve the deposition rate,and effectively control the corresponding target element content in the film by adjusting the process parameters.HiPIMS has the characteristics of low duty cycle and high peak power on the target surface,which can highly ionize the sputtered material with a low average power.By bombarding the substrate with a high-energy ion beam,the phase composition and microstructure of the films can be effectively controlled,and the low-temperature preparation of dense high-entropy alloy films can even be achieved.Furthermore,the interval between the discharge voltage pulses for each sputtering target in high-power impulse magnetron co-sputtering must be determined to broaden the process window,enhance the glow discharge stability,and ensure uniformity of the film composition and microstructure as well as experimental repeatability.Thus,the three-target high-power impulse magnetron co-sputtering with controllable time interval between pulses is employed to deposit high-entropy alloy nitride films. 65Mn steel and single-crystalline Si(100)were used as substrates.Prior to the(TiSiAlCrV)N films,a TiSiAlCrV buffer layer with the thickness of 200-250 nm was prepared on the substrates to increase the adhesion.(TiSiAlCrV)N high-entropy alloy nitride films were prepared via three-target high-power impulse magnetron co-sputtering without substrate heating.TiSi alloy target,AlCr alloy target,and V target were used and the interval between voltage pulses of these targets was controlled.The nitrogen content was controlled by varying the flow ratio of N2/(Ar+N2)from 25%to 66.7%,donated as RN2.The effect of RN2 on the chemical composition,phase composition,deposition rate,microstructure,and properties of the(TiSiAlCrV)N films was investigated.The phase composition,hardness(H)and elastic modulus(E),wear and corrosion resistance of the films were analyzed respectively through glancing incidence X-ray diffraction(GIXRD),nano-indenter,tribometer,and electrochemical workstation.The scanning electron microscope(SEM)equipped with energy-dispersive spectrometry(EDS)and a white-light interferometer were used to test the chemical composition,surface and cross-sectional morphologies,and wear tracks. The results indicated that the nitrogen flow ratio did not alter the phase composition of the film and all the(TiSiAlCrV)N films had NaCl(B1)type FCC structure.As RN2 increased,the nitrogen content of the film increased slightly,the deposition rate decreased,the lattice constant increased,and the grain size decreased,reaching the minimum value of 6.7 nm at 66.7%.The preferential orientation was the(220)plane when the film was fabricated at RN2 of 25%,and it was altered to the(111)plane with RN2 increasing to 40%,50%,57.1%and 66.7%.The H,H/E,and H3/E2 increased with RN2 increasing,and reached their maximum values of about 14.77 GPa,0.071 and 0.075 GPa,respectively,at RN2 of 66.7%.The film deposited at RN2 of 66.7%has the lowest wear rate of around 6.84×10-6 mm3/(N·m),indicating the highest wear resistance.This film shows abrasive and oxidation wear mechanisms,whereas films fabricated at RN2 of 25%,40%,50%and 57.1%experience abrasive,fatigue,and oxidation wear.All films can provide effective corrosion protection for 65Mn steel in simulated soil solution.The film prepared at RN2 of 66.7%has the best corrosion resistance due to the dense structure.