Chemical vapour deposition of PyC–SixCy–SiC–Si3N4 multilayer with graded C…SiC transition

MicroRaman spectroscopy of protective coatings deposited onto C/C–SiC composites

“…1 In the case of Si bands at 520 cm 21 there is no evidence of the presence of such a band in the spectrum. The high intensity of the sp 3 /sp 2 (1350 : 1580) doublet at the beginning of the graded layer indicates an excess of carbon and therefore the layer is not stoichiometric.…”

“…Chemical concentration, gas flow and temperature were controlled, leading to the deposition of PyC (as a bonding layer) and graded Si x C y as described in Ref. 1. After the deposition, the sample was cut so that a cross-section was exposed.…”

“…1 Depending on the properties required, these coatings can be multilayers of pyrolytic carbon (PyC), SiC, TiSi 2 , Si 3 N 4 and others. However, choosing the most suitable coating can often be complex.…”

“…These layers consist of PyC, which results in smoothing of the substrate, followed by a controlled graded Si x C y transition coating for bonding to the stoichiometric SiC layers. 1 The PyC possesses either a diamondlike or onionlike structure depending on the process conditions. The properties of the graded Si x C y layers in some ways are similar to those of ceramic-matrix composites as described in Ref.…”

Chemical vapor deposition and composition–depth profiling of a graded coating by Auger electron spectroscopy used in conjunction with taper polishing

“…[2,3]. The techniques for fabrication of functionally graded materials include chemical vapor deposition (CVD), physical vapor deposition, plasma spray, powder metallurgy and sol-gel techniques [4][5][6][7][8][9]. TiC x N 1Àx coatings deposited on WC/Co, graphite and steel by CVD have been used in many areas ranging from cutting tools to nuclear materials owing to high hardness, superior inertness and low Z-number.…”