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Titanium aluminum nitride films: A new alternative to TiN coatings
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1986
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Sodium ChlorideCrystal StructureAluminium NitrideEngineeringMechanical EngineeringThin Film Process TechnologyAnodizingCorrosionTin CoatingsCorrosion ResistanceProtective CoatingMaterials ScienceMaterials EngineeringTial FilmsLight MetalMicrostructureCorrosion TechnologyHigh Temperature MaterialsSurface ScienceApplied PhysicsThin FilmsMetal Processing
TiAl films are produced by sputter ion plating and exhibit higher oxidation resistance, oxidizing only above 800 °C compared to TiN’s 550 °C. Reactive sputtering from a TiAl 50:50 target produced films with 27.5 % Ti, 28.9 % Al, and 43.6 % N. The resulting TiAlN films crystallize in a NaCl structure (a = 4.20 Å) with HV 2100–2300 hardness, and Al incorporation enhances oxidation resistance and cutting performance, yielding more than twice the performance of TiN‑coated drills on two steels.
TiAl films have been produced in various compositions by using the sputter ion plating process. Films sputtered reactively from a target with the composition of TiAl 50:50 at. % have been deposited with a composition of 27.5 at. % Ti, 28.9 at. % Al, and 43.6 at. % N. The crystal structure found was that of sodium chloride with a lattice parameter of 4.20 Å; the microhardness such films was found to be HV 2100–2300. The incorporation of Al into the nitride films improves the oxidation resistance as well as the cutting performances of TiAlN coated drills. TiN films start to oxidize at a temperature level of 550 °C, whereas TiAl coatings react with hot air at a temperature of 800 °C severely. TiAlN coated drills have been tested with two different steels and performed better by a factor >2 compared with TiN coated drills.