Abstract:
A head drum is coated with double films, each having different characteristics, by forming a first diamond-like hard carbon film of high degree of hardness and then forming a second diamond-like hard carbon film of a lower degree of hardness thereon. The degree of hardness of the second film is lower than that of the first film. The double coating is performed by means of a synthesizing apparatus which comprises a reactor consisting of a power supply electrode, a workpiece support and an annular ground electrode spaced from the stacked head drums by a predetermined distance.
Abstract:
Disclosed are an apparatus and a method to synthesize powders typed diamond with the size between several tens nm to several μm in diameter using conventional CVD processes for deposition of diamond films. Gas phase nucleation has been induced on the boundary of plasmas, and as a result the spherical diamond powders accumulated have been obtained on circumferences of the normal substrate. With a modification of a substrate structure, a large area accumulation of the diamond powders of around 100 mm in diameter has been accomplished.
Abstract:
A high curvature diamond field emitter tip fabrication method includes forming on a substrate a diamond film composed of square (100) phase-oriented facets and (111) phase-oriented facets distributed thereabout and columnar diamond particles having defect density differences between the diamond formed beneath the (100) and (111) diamond growth facets, and etching the diamond film using a oxygen-containing gas plasma. Further, the method includes forming on a substrate a diamond film composed of square (100) facets and (111) facets distributed thereabout and columnar diamond particles having defect density differences between the diamond formed beneath the (100) and (111) diamond growth facets, forming a supporting film on the diamond film, removing the substrate therefrom, and etching the diamond film using an oxygen-containing gas plasma after any one of the previously described steps.
Abstract:
A fabrication method for a diamond-coated cemented carbide cutting tool includes electrolytically etching the surface of a cemented carbide cutting tool with a NaOH or KOH aqueous solution or chemically etching the surface of the cemented carbide cutting tool with a KMnO.sub.4 +KOH aqueous solution, and depositing a diamond film on the cemented carbide cutting tool. A stronger etching effect than by using a Murakami solution can be achieved, and no poisonous material is included in the etchant. In addition, disposal of the waste etchant is made simpler, and the adhesion between the diamond film coating and the cemented carbide cutting tool can be strengthened.
Abstract:
A head drum is coated with double films, each having different characteristics, by forming a first diamond-like hard carbon film of high degree of hardness and then forming a second diamond-like hard carbon film of a lower degree of hardness thereon. The degree of hardness of the second film is lower than that of the first film. The double coating is performed by means of a synthesizing apparatus which comprises a reactor consisting of a power supply electrode, a workpiece support and an annular ground electrode spaced from the stacked head drums by a predetermined distance.
Abstract:
An improved diamond film synthesizing apparatus and a method thereof using a direct current glow discharge plasma enhanced chemical vapor deposition advantageously providing a plurality of cathodes for forming a relatively large plasma size, which includes a reactor having an upper wall and a bottom wall; a plurality of spaced apart cathode holders half inserted into the upper wall of the reactor, arranged in a triangle when looking dowawardly over the head of the reactor; a plurality of cathode connecting rods, each of which is threadly connected to the cathode holders inside the reactor, respectively; a plurality of cathodes, each of which is threadly connected to the cathode connecting rods, respectively; an anode half inserted into the bottom wall of the reactor and having a substrate attached on the top thereof, whereby all the cathodes and the anodes are spaced apart inside the reactor by a predetermined distance; and a gas supplier connected to one side wall of the reactor having a circular gas supplying tube having a plurality of holes for injecting gas into the reactor. In addition, the diamond film synthesizing method using a direct current glow discharge plasma enhanced chemical vapor deposition comprises the methods of cutting off the heat transfer from a cathode to a cathode holder, thereby maintaining the temperature of a cathode to be within a predetermined range for a stable production of a plasma.
Abstract:
A diamond film depositing apparatus and method are disclosed in which a uniform and large plasma is formed on a substrate having a diameter of larger than 100 mm without using a heated filament cathode, without applying a magnetic field thereto, and without using a ballast resistance. The thusly formed plasma is maintained stably for a long time, so that a diamond thick film having a diameter of larger than 4 inches and a thickness of over hundreds of &mgr;m can be deposited on a flat or curved substrate and also on a Si wafer.
Abstract:
In order to provide an excellent toughness and a sufficient adhesive force without any limit in the content of other carbides in the substrate material and Co and in the size of the cemented carbides grains, the present invention provides a diamond film coated cutting tool, comprising a surface layer which cemented carbide grains are grown abnormally on the cemented carbide substrate, and a diamond film formed on the surface layer, and also a method for manufacturing a diamond film coated cutting tool, comprising the steps of heat-treating a surface of a cemented carbide substrate under a decarburizing atmosphere until the surface changes to a &eegr; phase, heat-treating the surface-decarburized cemented carbide substrate under a carburized atmosphere, depositing a diamond film on the carburized surface of the cemented carbide substrate.
Abstract:
A method of synthesizing an even free-standing diamond film without growth cracks is disclosed. The intrinsic tensile stress of a diamond film is compensated by an artificial compressive stress with a step down control of the deposition temperature during deposition. After a diamond film is deposited with a predetermined thickness at a deposition temperature, the deposition temperature is decreased in multiple steps during the deposition. The bending of the diamond wafer is minimized by using a tungsten substrate with higher elastic modulus than molybdenum.
Abstract:
An aluminum head drum for use in a video cassette recorder is coated with a protective layer comprising diamond-like carbon. The protective layer of diamond-like carbon is obtained using a plasma-enhanced chemical vapor deposition method and has a thickness ranging from 0.3 .mu.m to 2.0 .mu.m. The protective layer has a varying mechanical hardness, wherein the mechanical hardness has a maximum value at a region of the protective layer coming in contact with the aluminum head drum, decreases smoothly and continuously and reaches an minimum value at a region of the protective layer coming in contact with atmosphere. Micro-Vicker's hardness of the region of the protective layers coming in contact with a video tape is 1.5-2.0 times that of the magnetic substance constituting the video tape.