Effect of the microstructure on the cutting performance of superhard (Ti, Si, A...

• Author(s): Fernandes, C. ; Carvalho, S. ; Rebouta, L. ; Vaz, F. ; Denannot, M. F. ; Pacaud, J. ; Rivière, J. P. ; Cavaleiro, A.
• Date: 2008
• Persistent ID: http://hdl.handle.net/1822/27576
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): (Ti,Si,Al)N; Microstructure; HRTEM; XRD
• Document Type: Article
• Language: English

Description

A d.c. reactive magnetron sputtering technique was used to deposit (Ti,Si,Al)N coatings onto WC–Co cutting tools. The microstructure of the coatings was analysed using X-ray diffraction (XRD) and highresolution transmission electron microscopy (HRTEM) measurement. Before the cutting experiments, the XRD results revealed a structure indexed to an fcc TiN. The results obtained by the XRD tests, with detector variation in asymmetric mode (rocking curves) showed a decrease in the quality of the fiber texture in the (111) grains with the change on deposition chamber geometry (two magnetrons in place of four magnetrons). Cross-sectional HRTEM images of the (Ti,Al)N sample showed grains with a diameter between 16 and 30 nm, while for the (Ti,Si,Al)N samples grains with a diameter between 6 and 10 nm were observed. Furthermore, through the visualization of bright field images it was possible to discern a columnar structure. For samples prepared at high deposition rates (2 mm/h), HRTEM micrographs revealed the formation of the multilayer stacking of (Ti,Si)N/(Ti,Al)N.