Abstract: The present invention relates to a plasmatron for a plasma coating apparatus including an anode having an axial bore through which gas is passed around a cathode and an electric arc is established between the anode and cathode. A powder feed line or conduit is connected between the anode and a powder feed source. The feed line has a straight section along a portion of its length terminating at the axial bore of the anode. The straight section of feed line has a ratio of length to internal diameter at least about 4.8, preferably 10 and even more preferably 15.

Abstract: The present invention relates to a plasmatron for a plasma coating apparatus including an anode having an axial bore through which gas is passed around a cathode and an electric arc is established between the anode and cathode. A powder feed line or conduit is connected between the anode and a powder feed source. The feed line has a straight section along a portion of its length terminating at the axial bore of the anode. The straight section of feed line has a ratio of length to internal diameter at least about 4.8, preferably 10 and even more preferably 15.

Abstract: A process for diffusion bonding a coating of Nitinol intermetallic compound to a surface of a metallic substrate includes heating and cleaning the surface of the substrate to a metallurgically clean condition by creating a plasma arc in a plasmatron and partially ionizing and heating a stream of inert gas in the plasma arc. The stream of partially ionized gas from the plasmatron is directed to the surface of the substrate to remove oxides and other contaminants from the surface. Nitinol powder is entrained in a mixture of hydrogen and argon gasses heated and ionized in the plasmatron, thereby heating the powder to a partially molten state. The partially molten power is ejected in the gas mixture from the plasmatron at high velocity and impacts against the metallurgically clean heated substrate surface to produce a diffusion bond between the Nitinol intermetallic compound and the metal substrate.

Abstract: A hand tool for deburring and beveling the edge of a part includes a small, hand-held driving tool coupled to a shaft on which are mounted a rotatable cutting blade and a pair of roller bearings of conventional, cylindrical configuration on opposite sides of the cutting blade. The cutting blade is secured for rotation with the shaft by a nut mounted on a threaded outer end of the shaft to compress the inner races of the roller bearings against the cutting blade and against an annular shoulder on the shaft. Upon placement of the pair of roller bearings against opposite sides of a part having an edge to be deburred and beveled, the driving tool rotatably drives the shaft and thus the cutting blade so as to accomplish the desired deburring and beveling action. The depth of beveling along the edge of the part is determined by size and shape of the cutting blade, the diameter of the pair of roller bearings and the space therebetween.

Abstract: A powder feed control system employs an arrangement of conduits and valves for selectively directing a gas flow either through a powder feeder or through a bypass so as to quickly and precisely control the introduction of powder into and the removal of powder from the gas flow in a plasma spraying system. The arrangement of conduits and valves includes a two-way solenoid operated valve for directing the gas flow either into a powder feeder through a main conduit or into a bypass conduit which rejoins the main conduit on the other side of the powder feeder at a powder shutoff valve and a bypass and check valve. The bypass and check valve insures that the gas flow in the bypass conduit flows to the output rather than upstream to the powder shutoff valve.