In this paper, we report a microcrack toughening mechanism for enhancing the adhesion of diamondcoating. The oriented microcracks were formed within the TiC interlayer to dissipate strain energy and accommodate deformation via the crack opening-closing mechanism, thus enhancing the coating/substrate interfacial toughness. The delamination of diamondcoating was effectively prevented when the parallel microcracks were confined within the interlayer and arrested at interfaces of coating/interlayer/substrate. Density functional theory calculations revealed that the highly anisotropicfracture strength of the TiC phase energetically favors crack initiation and propagation along (100) planes only, which are 54.7° away from the interface. These microcracks are constrained inside the interlayer by the two strong interfaces in the substrate/interlayer/coating system. The new microcrack toughening mechanism with these combined features has a wide application to enhance the adhesion of thin-film coatings.
Published in Journal of Applied Physics, Volume 106, Issue 12, 2009, pages #123514-.
©Journal of Applied Physics 2009, American Institute of Physics.
Guo, H., Xiao, X., Qi, Y., Xu, Z-H., & Li, X. (15 December 2009). Enhance Diamond Coating Adhesion by Oriented Interlayer Microcracking. Journal of Applied Physics, 106 (12), #123514. http://dx.doi.org/10.1063/1.3267162