GB902841A - A rotary furnace retort for metallic diffusion treatment - Google Patents

Abstract

902,841. Coating with metals. METALLIC SURFACES RESEARCH LABORATORIES Ltd. Feb. 27, 1959 [April 3, 1958], No. 10839/58. Class 82 (2). A rotary retort for metallic diffusion treatment comprises a closed cylinder provided with a gas inlet, a gas outlet and a perforated inner tube, a metallizing substance being contained in the space between said inner tube and the wall of the cylinder or in said inner tube. In the first arrangement, as shown in Fig. 1, the metallizing composition, e.g. chromium lumps or granules, is contained in space 11 between wall 1 and perforated inner tube 7. Articles to be coated are loaded into chamber 10, and gases containing halogens or halogen-generating components are introduced into manifold 5 and thus into perforated tubes 8, whence they percolate through the metallizing composition, thus becoming charged with metallic halide vapour, to reach the articles in chamber 10. In the second arrangement, as shown in Fig. 2, the metallizing composition is contained in space 111 inside perforated tube 107. Articles to be coated are loaded into chamber 110, and gases containing halogens &c. are introduced through tube 108. Fixture 103 is a heating or cooling coil. Articles made of iron, nickel, cobalt, molybdenum, titanium, graphite, silicon, and alloys thereof may be coated with aluminium, beryllium, titanium, zirconium, vanadium, molybdenum, tungsten, manganese, copper, nickel, cobalt, silicon or boron. According to the Provisional Specification, the retort may also be used for bright annealing or carburizing.