Silicon carbide surface energy

Heteroepitaxy of diamond on c-BN has been successful (e.g., 105,106) due to the identical crystal stractures with a close lattice match (only 1.3% mismatch) between the two and the high surface energy ( 4.8 J/m ) of the c-BN (111) plane. The heteroepitaxy of diamond on silicon could be the key to electronic device apphcations of diamond. However, diamond has a large lattice mismatch with silicon (52%) and a much higher surface energy than silicon (6 J/m for diamond, 1.5 J/m for silicon), hi spite of this, there are several reports of oriented diamond film deposition on substrates like silicon, silicon carbide, etc., by various techniques (e.g., 108-112). 

Specific grinding energy (top) and area percent grinding-induced surface fracture (bottom) vs. the grain depth-of-cut to the -4/3 power for CVD silicon carbide. Tomita, Y. and Eda, H., Development of new bonding materials for fixed abrasive of grinding stone instead of free abrasives processing. Bull JSPE (in Japanese), 61, 10 (1995) 1428 Lawn, B.R. and Swain, M.V., Microfracture beneath point indentations in brittle solids, J Mater Sci, 10 (1975) 113. 

As reported earlier, all of the materials experienced an increase in weight as a result of exposure to a sulfuric acid decomposing environment at 900 °C. X-ray photoclectron spectroscopy (XPS) and Energy dispersive X-ray (EDX) analysis on a scanning electron microscope (SEM) indicated that the reaction products were silica. After exposure, both the silicon carbide and silicon nitride specimens exhibited a slight increase in strength, presumably due to the blunting of surface flaws by the formation of silica. 

Silicon carbide is a semiconductor material that is why it is a potential catalyst of thermal oxidation and pyrolysis processes. The silicon carbide partieles have sharp comers and it allows to expect the appearance of physical and chemical activity in the processes of adsorption and chemical reactions (due to Ihe presence of unpaired electrons and excess surfece energy). Silicon carbide also can be used as so ealled microbarrier because of its plastic forms on the surface layers of the material. But the usage of silicone carbide in elastomeric materials is poorly understood. 

A study of Vickers hardness of polycrystalline ceramics revealed that cracking may cause critical transition points in the Vickers ISE trends. The transition point was associated with extensive cracking in and around the indentation and a shift in the energy balance during indentation. Different ratios of the indentation work are expended on volumetric deformation and surface fracture processes above and below the transition point. The transition point was very distinct for brittle materials such as silicon carbide. The Vickers hardness transition point was related to a new index of ceramic brittleness defined as ... 

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