GB950729A - Method and apparatus for shaping metal workpieces by electrolysis - Google Patents

Abstract

A method of removing metal or metalloid material, e.g. tungsten carbide, form a workpiece 90 comprises supplying electrolyte at a pressure of several atmospheres to the space between the work 90 and a cathode 82, and heating the electrolyte, at 78, while it is under pressure and before it escapes from the interspace, to a temperature above the atmospheric boiling point but below the boiling point at the higher pressure, and recirculating the electrolyte. The electrolyte is delivered by a pump 70 from a reservoir 72 to the hollow interior of the cathode 82, a bypass 98 being provided. Valves 80, 100 enable a desired pressure, e.g. 120 p.s.i., which is indicated at 88, to be achieved at the electrode 82, an overflow 94 leading back to the reservoir 72. The electrode 82 is automatically advanced, e.g. as described in Specification 943,101. The heater 78 is thermostatically controlled. Gases escape from the enclosure 106 or are vented to atmosphere, steam condensing and being returned to the reservoir 72 via the overflow 94. Cooling coils 102, 104 may be provided. In a modification, the return flow is from the base of the enclosure 106, so that the work is not submerged, and the by-pass 98 leads directly to the reservoir. Further, an exhaust duct leads from the top of the enclosure 106 through a motor driven blower to a heat exchanger where steam is condensed and from which the condensate is returned to the reservoir. The electrode 82 may be as described in Specification 943,101.