Abstract: The object of the present invention is a deposition process of a coating of the ceramic type based on carbides, nitrides, or carbonitrides of metallic elements such as Cr, V, Zr, W, Mo, Co, Mn, Ni, Hf, Ta, Ti, Nb and Fe in which the coating of the ceramic type is deposited at low temperature in the vapour phase on a metallic substrate from organo-metallic precursors wherein, prior to this deposition in the vapour phase and without subsequent placing in contact with an oxidizing and/or polluting atmosphere, a reactive ionic pickling is carried out in a reducing atmosphere.

Abstract: A surface deposition or surface treatment reactor, in particular for chemical vapor deposition, has an annular reaction chamber (C.sub.R) delimited by two tubular walls (1, 2), in particular of quartz. A first hearing unit is arranged inside the tubular wall (1) and a second heating unit is arranged around the outer tubular wall (2). Said units are controlled by heat-regulating means in order to ensure a predetermined longitudinal temperature profile in the reaction chamber (C.sub.R). The gas phase is distributed at a longitudinal end of the chamber (C.sub.R) through distribution ducts (18) and removed by suction at the other end through pumping ducts (20). The substrates (S), which may be very numerous, are swept simultaneously by the gas phase and the perfect control of the temperature distribution and of the flow makes it possible to obtain a uniform treatment of the desired type which is identical for all the substrates.

Abstract: The object of the invention is a one-step deposition process of a coating of the ceramic type based on nitrides or carbonitrides of at least one metallic element selected from Cr, V, Zr, W, Mo, Co, Mn, Ni, Hf and Ta on a metallic or ceramic substrate, massive or obtained from fibres, by deposition in the vapor phase wherein a coating is deposited on the substrate by a chemical means at a pressure lower than 10 kPa at a temperature lower than 600.degree. C. and by using a system of precursors constituted simultaneously of:an organo-metallic precursor of the said metallic element selected from the organo-metallic compounds of the sandwich type of general formula:[Ar.sup.1 M Ar.sup.2.sub.n ]L.sub.x L'.sub.ya nitrogen precursor selected from ammonia and hydrazine.

Abstract: A process for producing a protective film on a magnesium based metallic substrate comprising producing successive deposits by vapor phase chemical deposition of at least one intermediate layer of metallic aluminum, and at least one surface layer of metallic oxide, and for the intermediate aluminum layer using a precursor chosen of triisobutylaluminum, heating the substrate to a temperature between 250.degree. C. and 320.degree. C., and for the surface layer selecting an appropriate precursor, heating the substrate to an appropriate temperature and introducing the precursor vapor to produce a protective film having a high surface hardness and strong adherence to the magnesium based substrate with high inertness in the electrochemical series, and forming an effective protection under both static and dynamic conditions.

Abstract: The present invention relates to a process for making bioactive coatings on osseous prostheses, wherein, from solutions, a mist of particles containing calcium ions and orthophosphate ions is made and said mist is brought into contact with an implant made of inert material under such operational conditions that at least one desired calcium phosphate is formed by reaction on the hot surface of said inert implant, and to the osseous implants obtained by this process.

Abstract: A process for depositing a layer of a semiconductor composition comprising elements M(III) and M'(V) selected from group III and group V elements, respectively onto a substrate. The process comprises: contacting the substrate with a coordination compound in the gaseous phase, the compound having the formula: ##STR1## wherein M(III) and M'(V) are bonded to one another by a donor/acceptor bond and wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, and R.sub.6 are chemical radicals other than hydrogen with at least one of the radicals R.sub.1, R.sub.2, and R.sub.3 being an electron donor serving to stabilize the donor/acceptor bond between elements M(III) and M'(V). The process further comprises decomposing the coordination compound so as to break the chemical bonds between the radicals and the elements M(III) and M'(V) without breaking the donor/acceptor bond, so as to cause the semi-conductor composition to deposit onto the substrate.