Nanostructured Carbon Coatings on Silicon Carbide: Experimental and Theoretical Study

Abstract

Nanostructured carbon coatings can be obtained by the extn. of metals from carbides (SiC and TiC) using chlorine or chlorine-hydrogen mixts. This is a versatile technol. because a variety of carbon structures can be obtained on the surface of carbides in the same reactor. Not only simple shapes, but also fibers, powders and components with complex shapes and surface morphologies can be coated. This technol. allows the control of coating growth on the at. level, monolayer by monolayer, with high accuracy and controlled structures. In this work, the structure and properties of carbon coatings obtained on the surface of carbides have been investigated using transmission electron microscopy (TEM). Mol. dynamics (MD) was used to model the growth of carbon coatings on SiC and the simulation data are compared with TEM results. The simulation can provide guidance to understand the growth mechanisms and potentially possible carbon structures. Ordered and disordered graphite, nanoporous carbon (sp. surface area of >1000 m2/g) and hard carbon films can be formed on SiC surfaces depending on the temp. and gas compn. These carbon coatings can be used as tribol. coatings having a low-friction coeff. for a variety of applications, from heavy-load bearings to micro-electro-mech. systems (MEMS); protective coating for sensors and tools, intermediate thin films for further chem. vapor deposition (CVD) deposition of diamond, weak coatings on SiC reinforcements for composite materials, coatings on SiC powders for improved sinterability, catalyst supports, and mol. membranes. [on SciFinder(R)]