Nucleation and growth of CVD α-Al2O3 on TixOy template
(English)Article in journal (Other academic) Submitted
The microstructure, phase and chemical composition of TixOy templates used to nucleate α-Al2O3 on Ti(C,N) coated cemented carbide have been elucidated using scanning electron microscopy, X-ray diffraction, Auger electron spectroscopy and Time-of-Flight Secondary Ion Mass Spectrometry. Further, the adhesive strength of the α-Al2O3-TixOy-Ti(C,N) interfaces was investigated using scratch adhesion testing.
The present study confirmed that the as-deposited template consisted of a Ti4O7 phase which during subsequent deposition of the Al2O3 layer transformed to a Ti3O5 phase and that the grown Al2O3 layer consisted of 100% α-Al2O3. Furthermore, the results showed that the lowest interfacial strength within the multilayer structure was exhibited by the Ti(C,N)-TixOy interface and that the transformation of Ti4O7 to Ti3O5 in the template resulted in formation of pores in the Ti(C,N)-template interface lowering the interfacial strength even more. The use of surface analysis techniques such as Auger electron spectroscopy and especially Time-of-Flight Secondary Ion Mass Spectrometry enabled trace element analyses using depth profiling to characterise the thin interfacial layers in detail.
CVD, α-Al2O3, nucleation, template, adhesion
Research subject Materials Science
IdentifiersURN: urn:nbn:se:uu:diva-172446OAI: oai:DiVA.org:uu-172446DiVA: diva2:514691