GB666315A - Improvements in methods for treating surfaces of metallic work-pieces - Google Patents

Abstract

666,315. Coating with metals. CORPORATION SOC. ANON. EDRAS. Dec. 29, 1947. [Oct. 29, 1942; July 21, 1943] Nos. 34397/47 and 34398/47. Class 82(ii). Metallic supports are sprayed with molten metal in a finely divided state whilst subjected to ultrasonic vibration. The coating metal, which may be iron, lead, copper, aluminium, silver or magnesium with or without other metals, is supplied in the form of a wire to a spray gun and is melted by means of oxy-acetylene or electrically, spraying being effected by an inert gas such as nitrogen or carbon dioxide. When more than one metal is sprayed, a wire having a core of one metal disposed within another metal or metals may be used; for instance, a core of lead powder or shavings, which may be impregnated with oil or alcohol and a flux, may be enclosed in concentric metal or alloy sheaths; or, the core may comprise copper shavings' with 0.5-2 per cent of tin; cr, red copper may be filled with lead with or without colloidal graphite; or, lead or a lead-tin alloy may be filled with powdered antimony alone or mixed with copper or lead; or, concentric cylinders of red copper and tin may be used. Alternatively, a single metal may be employed having a flux core comprising boric anhydride with or without the permanganate of the metal used, or, simple or double fluorides such as cryolite, with or without a plasticizer such as stearine, cellulose or polymerization products. During the coating operation, a bush 1 is supported in a cooled block 3 carried on a nickel armature 6 connected to an ultrasonic generator of the magnetostriction type. Prior to coating, the bush may be wire brushed or coated with zinc. Alternatively, a pre-coated supporting surface may be secured to a bush by welding or by adhesive; such surface may, for instance, be of lead bronze containing 30 per cent lead on a fine cloth of tin bronze containing 6 per cent tin so woven as to form projections to provide a keying surface; after spraying, the material may be heated and quenched. The Specification as open to inspection under Sect. 91 refers also to the use of lead cores coated with aluminium or its alloys or magnesium or its alloys as spray material; to sweeping a bush with a jet of hydrogen brought to a given temperature during coating; to tinning, spraying with pure aluminium, coating with copper, parkerizing and blast cleaning with sand or steel shot, prior to the coating operation; and to coating plastic materials, papers, jute and textiles, impregnated or not, which materials may be destroyed in subsequent heat treatment. This subject-matter does not appear in the Specification as accepted.