Study Of TiB₂/TiAlN Nanoscale Multilayered Coatings And BaTiO₃ Thin Film Synthesized Using Radio-frequence Magnetron Sputtering

This paper reported the design and synthesis of TiB₂/TiAlN multilayered coatingsand BaTiO₃ coating with nanoscale on Si(100) by ultrahigh vacuum r.f. magnetron sputtering system. The The mechanical properties of the multilayered coatings including hardness, elastic modulus and adhesion were measured by profiler and Nano Indenter XP system. X-ray diffraction was employed to investigate layered and crystal structure of the coatings. Multi-functional tester was employed to investigate the wear restistance of the coatings. Influence of differernt process parameters on the structural and mechanical properties of the multilayed coatings was discussed.In the study of TiB2/TiAlN nanolayer coatings, effect of bilayer periods, thickness ratio on the structure and mechanical properties of the multilayered coatings were analysed and studied. High angle XRD patterns showed that monolithic TiB₂ andTiAlN coatings exhibited typical hexagonal and face-centered-cubic structure. TiB₂ monolithic layer had strong (001) orientation. Strong TiAlN(111) was observed in TiAIN monolayer. The sharp TiB₂ (001), TiAIN (111) and A1N (111) preferredorientations were found in both mulitlayered coatings. It proved multilayered coatings possessed well modulation structure and integrated crystal structure. Nano Indenter XP system showed that all multilayered coatings possessed higher hardness, elasticmodulus and fracture load than the rule-of-mixtures value of monolithic TiB₂ andTiAIN coatings. The multilayer with modulation period of 25 nm, t_TiB2:t_TiAlN=5:2 displayed the highest hardness ((?)36 GPa), modulus(403.6 GPa) and critical fracture load (31.2 mN). Tribological experiment showed that nanoscale TiB₂/TiAlNmultilayers exhibited better wear resistance than that of monolithic TiB₂ and TiAlNcoatings. The modulation period designed in experiment was accorded with the value calculated by the low angle XRD patterns.Little studies on relationship between microstructure and properties of nanoscale TiB₂/TiAlN multilayered coatings can be reported in recent literatures. All resultsabove demonstrated that r.f magnetron sputtering can produce nanoscale TiB₂/TiAlNmultilayered coatings with high hardness, high elastic modulus, high adhesion and low compressive stress by controlling process parameters during deposition. Therefore, these studies have great potential as protective coatings on cutting tools, increasing cutting rate, extending lifetime, exploring super-hardness materials and expanding application of industry on nanoscale multilayered coatings.A series of BaTiO₃ coatings with different substrate temperature were prepared used r.f. magnetron sputtering. The effect of substrate temperature on the structure and mechanical properties of the multilayered coatings were analysed by the X-ray diffraction and profiler and Nano Indemer XP system. Strong BaTiO₃(101) as well as weak BaTiO₃(200), (220) textures were observed in BaTiO₃ monolayer.