Influence of deposition parameters on microstructure and mechanical properties of chemical vapor deposited Ti1-xAlxN coatings. (June 2023)

• Record Type: Journal Article
• Authors: Saringer, Christian; Tkadletz, Michael; Thurner, Josef; Czettl, Christoph; Schalk, Nina
• Is Part Of: International journal of refractory metals & hard materials. Volume 113(2023)
• Publication Date: 2023-06
• Subjects: Chemical vapor deposition -- Deposition parameters -- TiAlN -- electron microscopy -- Microstructure -- Mechanical properties; Heat resistant alloys -- Periodicals; Refractory materials -- Periodicals; Metallography -- Periodicals; Alliages réfractaires -- Périodiques; Matériaux réfractaires -- Périodiques; Métallographie -- Périodiques; Heat resistant alloys; Metallography; Refractory materials; Periodicals; Electronic journals; 669.73
• DOI: 10.1016/j.ijrmhm.2023.106203
• Languages: English
• ISSNs: 0263-4368

Abstract

Abstract: Using thermally activated chemical vapor deposition (CVD), it is possible to synthesize Ti1-x Alx N coatings with Al contents up to x > 0.8 in a face-centered cubic crystal structure. This is considered to be due to their quite high global Al content and due to the frequently observed self organized nanolamellar microstructure consisting of lamellae with high Al contents of x > 0.9 epitaxially stacked with lamellae where x ∼ 0.5. However, CVD is a complex process and the formation mechanism of the lamellae and the resulting coating properties are not yet fully understood. Here, we have investigated the impact of the deposition temperature, deposition pressure and rotation speed of the reactive gas feed on the microstructure and mechanical properties. Our results show that by varying the pressure between 10 and 185 mbar and the temperature between 700 and 820 °C the grain size and texture can be tailored. In addition to the amount of wurtzitic AlN formed, they govern the mechanical properties. Similarly, the nanolamella periodicity strongly depends on temperature and pressure, indicating that the reaction kinetics are responsible for their formation rather than the gas feed rotation. Highlights: Nanolamellar face-centered cubic CVD TiAlN deposited within wide parameter range. Effect of deposition pressure, temperature, gas supply rotation on microstructure. Pressure and temperature influence w-AlN content, grain size and orientation. Gas supply rotation mainly influences grain size.