Abstract: The invention relates to a process for coating a substrate composed of cemented carbide, a cermet, steel or ceramic with at least one Ti1-xAlxN layer by means of a DC sputtering process. The invention further relates to a workpiece or tool which has been coated by the above-described process and to the use thereof. It is an object of the present invention to provide a process by means of which it is possible to produce coatings which combine the advantages of the sputtering process and the arc process, i.e. to make it possible to obtain a coating which has a low roughness and an advantageous (200) texture. A further object of the present invention is to provide a workpiece which has a coating having the properties mentioned. A further object of the present invention is to use tools which are particularly suitable for machining metals. The object achieved by the process is distinguished by ionization aids being used for increasing the plasma densities.

Abstract: The invention relates to a process for coating a substrate composed of cemented carbide, a cermet, steel or ceramic with at least one Ti1-xAlxN layer by means of a DC sputtering process. The invention further relates to a workpiece or tool which has been coated by the above-described process and to the use thereof. It is an object of the present invention to provide a process by means of which it is possible to produce coatings which combine the advantages of the sputtering process and the arc process, i.e. to make it possible to obtain a coating which has a low roughness and an advantageous (200) texture. A further object of the present invention is to provide a workpiece which has a coating having the properties mentioned. A further object of the present invention is to use tools which are particularly suitable for machining metals. The object achieved by the process is distinguished by ionization aids being used for increasing the plasma densities.

Abstract: The invention relates to a method for producing a wearing protection layer according to a CVD method. Said protection layer consists of a plurality of thin individual layers having a layer thickness of 1 to 100 nm respectively. The respective individual layers are successively deposited on a substrate body. The invention also relates to a correspondingly coated substrate body. According to the invention, the CVD method which is activated by means of a glow discharge plasma is carried out under a pressure of 50 Pa to 1,000 Pa and at a temperature of not more than 750 ° C.

Abstract: A cutting tool for chip removal machining is composed of hard metal, cermet or ceramic as a sutrate coated with a surface coating being composed of both hexagonal and amorphous boron nitrides. At least an outer most coating is being composed of boron nitrides a thickness of between 1 and 5 .mu.m. The surface has a total thickness which does not exceed 20 .mu.m and at least 20 volume % of the outermost coating is composed of hexagonal boron nitride. The infrared spectrum of the outermost boron nitride layer has absorption lines the wave numbers at 800 to 1400 cm.sup.-1.

Abstract: A composite body for use, for example as a cutting tool, having a metal-carbonitride layer of titanium, zirconium or hafnium carbonitride with at least two of these metals in the lattice structure as deposited by a CVD or plasma-activated-CVD process.

Abstract: An apparatus for producing solid fine particulates has a substantially closed reaction vessel and a hollow gas input conduit inside the vessel formed with a multiplicity of similar outlet apertures each having a flow cross section of at most 2 mm.sup.2. The conduit has an overall cross-sectional area equal to at least 100 times the flow cross section of a one of the apertures. A foraminous structure in the vessel surrounds the conduit and an electrode is provided in the vessel outside the foraminous structure. A direct-current power supply has a negative side connected to the foraminous structure and a positive side connected to the electrode while the input conduit is at ground potential so that a glow discharge is created in the vessel between the foraminous structure and the electrode.

Abstract: A process of forming a tool in which directly on the surface of the base body of the tool by base plasma activated chemical deposition a first PCVD layer of titanium carbide, titanium carbonitride, titanium nitride, zirconium carbonitride, and aluminum oxide is formed. Directly on this first layer by a nonplasma-activated CVD a second layer of titanium carbide, titanium carbonitride, titanium nitride, zirconium carbonitride, and aluminum oxide is formed. The steps are repeated to build up a coating so that it consists of a multiplicity of layers in a PCVD-CVD-PCVD-CVD structure.

Abstract: In order to improve the wear characteristics of tools with diamond cutting edges, it is proposed to coat the diamond body with a 0.5 to 6 .mu.m thick layer of at least one oxide of the metals zirconium and/or yttrium and/or magnesium and/or titanium and/or aluminum, preferably aluminum oxide. The coating is deposited from the gas phase at gas-phase temperatures up to 800.degree. C. Preferably the pulse-plasma CVD process is used for the coating. The diamond tools so coated are particularly suited for chip-forming machining of carbon-affinitive materials, such as iron-containing materials or steel.

Abstract: Composite body consisting of a hard metal, steel, ceramic, particularly sintered ceramic or cermet substrate body or a substrate body made of diamond or a nickel or cobalt-based alloy and of one or more surface layers, of which at least one, preferably the outer layer, consists of Al.sub.2 O.sub.3 with a fine crystalline structure, which has been applied by means of a plasma CVD process at substrate temperatures of 400.degree. C. to 750.degree., preferably 450.degree. C. to 550.degree., with a substrate body connected as cathode and with a plasma activation produced with a pulsed direct voltage.

Abstract: A composite body, especially for use as a cutting tool, for the lining of combustion chambers or for movable parts intended to have low wear which has a substrate of hard metal, steel, cermet or nickel or cobalt alloy. The substrate is provided with at least one fine-crystalline alpha-Al.sub.2 O.sub.3 layer deposited by plasma activated CVD at 400.degree. to 750.degree. C. With plasma activation by pulsed direct voltage with the substrate connected as the cathode.

Abstract: For the improvement of the wear properties of tools with cutting edge of cubic boron nitride (CBN) or polycrystalline cubic boron nitride (PCBN) it is proposed to coat the CBN or PCBN body with a 0.5 to 6 .mu.m thick layer of one or more oxides of the metals zirconium and/or yttrium and/or magnesium and/or titanium and/or aluminum, preferably aluminum oxide. The wear-resistant coating is deposited from the gas phase at gas-phase temperatures up to 800.degree. C. Preferably for the coating the pulse-plasma CVD process is used. The so-coated tools are particularly suitable for the chip-forming precision machining of hard iron and hard steel materials.

Abstract: Apparatus and method for corona-activated chemical vapor deposition. A substrate is positioned in a reaction vessel in all-around spaced relationship from the walls of the vessel. A cage having throughgoing perforations surrounds the substrate and is spaced from the vessel walls and the substrate. A corona discharge is generated along at least an inner surface of the cage by connecting the cage and substrate with a voltage source. A reaction gas mixture is passed through the cage and a coating is formed from the reaction gas mixture on the substrate.

Abstract: A tool having an extended service lift and including a hard metal body, and at least one surface layer composed of at least one hard substance selected from the group consisting of carbides, nitrides, and carbonitrides of titanium and zirconium, and having a chlorine content ranging from a finite amount up to 4 mass percent, the tool being produced by plasma-activated CVD process including: a. positioning the hard metal body in a CVD chamber having means for supplying direct voltage thereto, the hard metal body being connected to the direct voltage supplying means as a cathode thereof, b. introducing into the CVD chamber a reactive gas mixture including a nitrogen-containing substance, a carbon-containing substance, and at least one compound containing at least one of titanium and zirconium, and c.

Abstract: A process for coating a basic metallic substrate with a non-metallic coating layer with a plasma-activated CVD deposition generated by applying a pulsed DC voltage between the substrate and another electrode and by maintaining a potential of residual DC voltage between pulses of the applied voltage.

Abstract: A plasma-activated CVD process provides improved adhesion of the coated surface layers and employs, as the plasma exciting source, a pulsed direct voltage and a residual direct voltage which remains during the pulse intervals. The residual direct voltage is equal to or greater than the lowest ionization potential of the gases participating in the CVD process, but is no more than 50% of the maximum value of the pulsed direct voltage. The total thickness of the layer(s) does not exceed 30 .mu.m and the temperature of the basic tool body during the coating process is reduced, compared to prior art plasma CVD processes, and ranges from between 400.degree. to 800.degree. C., and is preferably kept below 600.degree. C.