Microstructural influence of the thermal behavior of arc deposited TiAlN coatings with high aluminum content

The influence of the microstructure on thermal behavior cathodic arc deposited TiAlN coatings was studied as a function isothermal annealing. Two compositionally similar but structurally different were compared, Ti 0·34 Al 0·66 N 0.96 coating with fine-grain structure consisting mixture cubic (c) and hexagonal (h) phases, 0·40 0·60 0.94 coarse-grain phase. By in situ wide-angle synchrotron x-ray scattering, spinodal decomposition confirmed both coatings. increased amount internal interfaces lowered temperature by 50 °C for dual-phase coating. During subsequent anneal at 1000 °C, transformation from c-AlN to h-AlN took place After min annealing, atom probe tomography detected small amounts (?2 at.%) c-TiN rich domains (?1 coarse-grained single-phase Similarly, same conditions, fine-grained exhibits higher content (?5 (?15 domains. study shows that stability is affected it can be used tune reaction pathway favorably. • Spinodal occurring phase microstructure. AlN apparent diffusivities all elements TiAlN-alloys microstructure.. affect TiAlN.