Research On Microstructure And Properties Of Ag-Ti-Cu/MoS₂ Films Fabricated By Ion Beam Assisted Deposition

Many of the key friction components in the aerospace field have been working in high vacuum,strong irradiation,atomic oxygen corrosion,thermal circulation,microgravity and other harsh environments for a long time.At the same time,it has put forward high requirements for weight reduction.It is undoubtedly the most economical and effective method to prepare advanced solid lubrication film with high performance,strong adaptability and long life on the surface of the friction pair parts by using the advanced film preparation technology.In this paper,Ag/MoS₂,Cu/MoS₂,Ti/MoS₂ and Ag-Ti/MoS₂ co-doped MoS₂ based solid lubrication composite film were prepared by Ion Beam Assisted Deposition(IBAD)system consisting of high-energy ion beam bombardment source+magnetron sputtering source+low-energy ion beam assisted source.The doping mechanism of Ag,Cu,Ti and Ag-Ti and the growth mechanism were systematically studied,which enriched the research system of MoS₂ based solid lubrication film.The surface morphology of the films was observed and analyzed by SEM and 3D optical profilometer.The microstructure of the films was analyzed by scanning electron microscope,energy dispersive spectrometer,grazing Angle X-ray diffractometer and Raman spectrometer.The hardness and elastic modulus of the films were measured by nano indentation.The friction and wear properties of the films were tested by a ball-disc friction and wear tester,and the wear morphology was observed and analyzed by scanning electron microscope and white light interferometer.The Ag/MoS₂,Cu/MoS₂ and Ti/MoS₂ composite films were prepared by IBAD technology with the same technological parameters.It is found that the great wettability between Ti metal and film are easy to grow into solid solution with low surface roughness by the layered growth mode.Ag/Cu and MoS₂ films have poor wettability.Ag is better than Cu growing in the lamellar mode and then in the island mode.Cu tends to grow in the island mode to form Cu-Cu rich area or coated with MoS₂,the surface roughness is large.Ti doping has a significant toughening effect,Ag doping has a significant toughening effect,and Cu doping shows creep effect.The results show that the film/substrate strength is in the order of Cu/MoS₂>Ag/MoS₂>Ti-Ag/MoS₂>Ti/MoS₂.The well tribology properties:Ti-Ag/MoS₂>Ti/MoS₂>Ag/MoS₂>Cu/MoS₂range of friction coefficients from 0.04 to 0.12.The composite preparation method--high energy ion beam blasting source+magnetron sputtering source+low energy ion beam assisted deposition source technology and the preparation of two-element co-doped Ag-Ti/MoS₂ solid lubrication film have good promotion and application value.The method of preparing thin film has practical guiding significance and long-term strategic value for the development of MoS₂based multi-layer gradient solid lubrication coating products.