Grain boundary strengthening of carbon-doped TiZrN coatings by laser carburization. Issue 4 (2nd October 2021)

• Record Type: Journal Article
• Authors: Kim, Taewoo; Lee, ByungHyun; Kim, Seonghoon; Hong, Eunpyo; Jo, Ilguk; Lee, Heesoo
• Is Part Of: Journal of Asian ceramic societies. Volume 9:Issue 4(2021)
• Page Start: 1489
• Page End: 1494
• Publication Date: 2021-10-02
• Subjects: Carbon-doped TiZrN coatings -- grain boundary strengthening -- amorphous carbon -- residual stress -- elastic recovery; Ceramics -- East Asia -- Periodicals; Materials science -- Periodicals; 620.1405
• DOI: 10.1080/21870764.2021.1997432
• Languages: English
• ISSNs: 2187-0764

Abstract

ABSTRACT: The improved mechanical properties of carbon-doped TiZrN coatings were investigated in terms of the microstructure and bonding state. The carbon incorporation and structural change were confirmed as a shift to lower degree of the diffraction pattern and the decreased grain size from 24.64 to 22.19 nm. The clear grain boundaries (GBs) were observed in the carbon-doped coating, and its fast Fourier transform (FFT) exhibited a diffused ring pattern. Edge dislocations were also observed in the inverse FFT image, indicating the formation of an amorphous phase due to laser carburization. From the X-ray photoelectron spectroscopy depth profile analysis, the carbon concentration decreased to 37.26 at.% after carburization, which is non-stoichiometric behavior that suggests the formation of the amorphous carbon (a-C) rather than carbides. Both sp 2 - and sp 3 -hybridized bonds were detected in the C 1s spectrum of the carbon-doped coating, indicating that the diffused carbon atoms were trapped in the GBs as a-C. The change in the GB structure increased the compressive residual stress from 3.97 to 4.63 GPa. In addition, the hardness, elastic strain to failure (H/E), and plastic deformation resistance (H 3 /E 2 ) of the carbon-doped TiZrN increased by 19.22%, 12.64%, and 49.59%, respectively, demonstrating the effect of GB strengthening.