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: 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 supplyi

Abstract: There is disclosed a method for depositing a diamond film on a substrate which utilizes high density direct current glow discharge at a glow-arc transition region to form plasma between a cathode and an anode in a reactor, wherein the cathode maintains its temperature at a range of 2,100 to 2,300.degree. C. and is composed of a plurality of U-shaped filaments which are aligned parallel to one another to form an array and each of which is made by bending a conductive wire.