Abstract: The laminate material comprises a sintered silicon carbide substrate (S) on which there is deposited by CVD a diamond layer in an enclosure (1) fed with 1% methane in hydrogen through a conduit (13), this gas mixture being activated by a hot tantalum filament raised to 2000.degree. C. This layer is thereafter covered, in another enclosure, with an AlN layer formed from a mixture of H.sub.2 +2% AlCl.sub.3 reacting with a mixture of H.sub.2 +1% NH.sub.3.

Abstract: The present invention relates to a compound body consisting of a substrate with a surface coating of one or more dense, finegrained diamond layers, where the diamond grains are directly bonded to each other. Extreme hardness makes the compound body suitable for wear parts- and tools applications. Very good heat conductivity and an extremely high electrical isolation resistance makes the compound body extremely useful to lead away heat in electronic components.

Abstract: A chemical vapor deposition method for the production of a composite body with one or more polycrystalline diamond layers, essentially free of intercrystalline binder phase, on a substrate of one of: (a) metalbonded hardmaterial compound; (b) ceramic material; or (c) a metal or an alloy, whereby the heated substrate is contacted with a gaseous mixture of hydrocarbon or hydrogen, which mixture has been activated by passing it over a tantalum heater heated to a temperature of 1500.degree.-2500.degree. C.Also disclosed is the use of the compound body in tools subjected to mechanical operations.

Abstract: A process for the preparation of an extrahard material based on tungsten and molybdenum carbides and having a hexagonal crystal structure identical with that of tungsten carbide. According to this process, one heats between 1000.degree. C. and a temperature T.sub.x, which is lower than the maximum stability limit of the Mo.sub.x W.sub.l-x C phase wherein 0.01.times.1, a mixture, intimate to the molecular or atomic scale, of tungsten and molybdenum the total content of which in Fe, Ni and Co does not exceed 0.1% with carbon and/or a carbon compound.T.sub.x is defined as follows:For 0.01<.times.<0.8, T.sub.x =2700-1375x.degree.C;For 0.8<.times.<1, T.sub.x =3400-2250x.degree.C.