Microstructural anisotropy effects on the metal cutting performance of decomposed arc evaporated Ti1-xAlxN coatings
(English)Manuscript (preprint) (Other academic)
The spinodal decomposition of cathodic arc evaporated cubic phase c-Ti0.34Al0.66N and c-Ti0.60Al0.40N coatings have been studied before and after continuous turning. By means of analytical transmission electron microscopy, we find that the evolving microstructure of c-Ti0.34Al0.66N, as simultaneously being exposed to high temperature of about 900 °C and high pressure of about 2.5 GPa, spinodally decompose into a spatially periodic, highly oriented and modulated interconnected array of coherent cubic AlN and cubic TiN rich regions along elastic compliant <100> crystal directions. Ti0.60Al0.40N instead decomposes into AlN and TiN rich domains in a more rounded and random microstructure. These effects are both explained by the elastic anisotropy which has earlier been shown to scale with Al content. The different evolving microstructure will lead to a different strengthening mechanism in the coatings during metal cutting and heat treatments, thus a different hardness and wear resistance behaviour.
IdentifiersURN: urn:nbn:se:liu:diva-78829OAI: oai:DiVA.org:liu-78829DiVA: diva2:536095