Fundamental Research On Preparation And Properties Of Tisin Coating

TiSiN coatings are a sort of material with extreme high hardness, very good high temperature oxidation resistance and thermal stability performance, become a research hotspot in the field of surface coatings. In this paper, adopt the arc ion plating-intermediate frequency magnetron sputtering composite deposition method, a series of TiSiN coating was prepared on YT15cemented carbide substrates, and the preparation process, microstructure, physical and mechanical properties, friction and wear characteristics were detailed studied.From theoretical calculation and finite element simulation analysis, studied residual thermal stress when the substrate material, coating thickness and transition layer are different, the results show that the finite element analysis and theoretical calculation results are close, choose YT15as substrate make a better adhesive strength, the residual thermal stress decreases with the coating thickness; The introduction of metal transition layer Ti can reduce the residual thermal stress of TiSiN coatings obviously.By controlling the preparation of the process parameters, deposit a series of TiSiN coatings on YT15with different Si element content(S1, S2, S3, S4), different coating thickness(H1, H2) and different transition layer thickness(Tl, T2). By measuring physical and mechanical properties and microscopic parameters, when the deposition temperature200℃, the substrate negative bias-150V, N2/Ar ratio110/60, Si target current4.0A, Ti target current65A, transition layer deposition for10min, coating deposition for150min. S3coating has the best comprehensive performance:Si element content is7.91%, hardness is3700HV, coating thickness is2μm, transition layer thickness is0.2μm, and adhesive strength is46N.Under the room temperature and dry friction condition, the friction property of TiSiN coating prepared are test by ball-plate rotating friction test. Study the friction and wear behavior of different TiSiN coatings, the results showed that the addition of Si element significantly improved the coating wear resistance, under the same friction conditions, the S3coating wear rate is the lowest, abrasion resistance is best, with the increase of friction load, friction coefficient and wear rate both have a downward trend. H2coating is too thick, easy to peel off when friction velocity is high. Under the same condition, thickness around2μm has lowest wear rate, best abrasion resistance. With the increase of friction velocity, the friction coefficient and wear rate is on the decline. T2coating easy peeling off because transition layer is too thick, performance declines, transition layer thickness about0.2μm, the coating has a highest binding strength, comprehensive performance is the best.Through the observation of the TiSiN coating grinding crack morphology, wear mechanism of different TiSiN coating is studied, the results show that under low load and low speed condition the wear form is mainly abrasive wear and tiny flake; Under high load, high speed condition, the main wear form is adhesive wear and plastic deformation and torn. Coating is too thick easy to exfoliate and failure in high speed, the transition layer is too thick, easy to produce cracks, crack expanding cause coating disbonding and failure. Si element content is too low, the hardness and wear resistance is poorer, abrasive wear and small spalling is obvious; Si element content is exorbitant, the coating hardness and comprehensive performance may reduce instead, coating peeling off likely to occur in the process of friction, Si element around7.91%the comprehensive performance of the coating is best.