Abstract: A method for drilling microscopic passages in a semiconductor body.The semiconductor 1 is incorporated into the anode of an electrolysis installation, one of its faces being in contact with the electrolyte 11 and the other containing a hole injection system. The holes migrate in the electric field from one face to the other; at the latter, dissolution of the semiconductor face in the electrolyte takes place. Gradually, passages are bored through the semiconductor along the trajectories of the holes. In the example, the holes are created photoelectrically in the gaps 2 between the opaque parts 4 applied to the transparent anode contact 3.

Abstract: In a computer-controlled mercury cell plant comprising a cell room, a mercury cell in the cell room, a control room remote from the cell room, and a central control apparatus including a memorized program digital computer arranged to adjust the height of anode banks in the cell in response to analog signals supplied by anode current sensors associated with the banks, a substation is provided in the cell room by means of which the analog signals are multiplexed, digitalized, encoded and serialized before leaving the cell room and are sent to the central control apparatus through a telephonic loop. The substation is preferably situated adjacent a front end of the cell at a distance not exceeding 2 meters. Signal disturbances and use of bundles of cables are thus avoided.

Abstract: In a known method of electrolytically marking metallic articles a hood having its bottom closed by a stencil with perforations is partially filled with an electrolyte and contains a cathode. An article to be marked is brought into contact with the stencil and constitutes the anode. The invention consists in maintaining the space within the hood at a partial vacuum sufficient to cause bubbles of air which have passed through the perforations in the stencil to flow upward in the hood, thus preventing electrolyte from seeping downward through said perforations.

Abstract: Disclosed is an electrolytic cell utilizing an electrolyte circulation system designed to prevent buildup of sludge within the cell compartments and to insure a greater current efficiency by reason of the even distribution of electrolyte solution flow within the cell. This electrolytic cell is particularly suited for organic electrochemical production.

Abstract: An electrode system is disclosed which comprises a vessel having an ion-permeable wall; a current feeder within said vessel spaced apart from said ion-permeable wall; and a plurality of electrically conductive particles free to move within a region between the current feeder and the ion-permeable wall and constituting, in use, a particulate electrode. The vessel incorporates at the base thereof a flow distributor such that, when the electrode system is in use, a fluid discharged into the vessel through the flow distributor debouches into the vessel in a direction away from the ion-permeable wall towards one or more surfaces in, or forming part of, the vessel and is deflected by said one or more surfaces towards the ion-permeable wall. An electrochemical cell and electrochemical process using such an electrode system are also disclosed.

Abstract: In the present plating apparatus the bath contains an electrolyte solution having a uniform ion concentration. A common electrode, a plating electrode and a standard electrode are arranged in the bath. A direct current source is connected between the common electrode and the plating electrode. A further, constant, direct current source is connected between the common electrode and the standard electrode. A potentiometer device is arranged for detecting resistance changes between these electrodes due to variations in the ion concentration and in the mobility of the electrolyte solution between the electrodes. A control is responsive to the potentiometer device for regulating the plating current supplied by the direct current source as a function of the potential difference detected by the potentiometer device, whereby a constant plating current density is achieved.

Abstract: An electroplating process and apparatus employs a horizontally oriented zirconium plate supporting the entire weight of a plurality of zinc anode blocks in an electrolytic solution with a zirconium bus bar connected to the zirconium plate on one end but having an opposite end external of the electrolytic bath.

Abstract: The electrolyzer has a refractory-lined hollow shell divided into a group of electrolytic cells and a magnesium collecting cell by a vertical separator plate that is shorter than the shell. Steel cathodes shaped as frames embrace a graphite anodes arranged in groups. To convey magnesium from the electrolytic cells into a magnesium collecting cell, at least two passageways are provided, each of them being substantially at right angles to the graphite anodes and to the separator plate. The separator plate has through perforations situated below the electrolyte level. Each of the passageways is confined between the wall of the electrolyzer shell and the portion of the cathode that faces towards the magnesium collecting cell. The width of each of the magnesium conveyance passageways is a maximum of three times the width of the gap across the adjacent graphite anode and steel cathode in each electrolytic cell.

Abstract: An electrolytic cell which comprises a standard calomel electrode supported n a container containing an etchant and a sample of the alloy or metal to be etched are electrically connected to a millivoltmeter or an X-Y recorder. The variation in potential generated by the electrolytic cell is measured as a function of time and used to determine the optimum time at which to end the process.

Abstract: An improved method of forming articles, such as airfoils, includes forming the major side surfaces of a plurality of airfoils in two groups or series along opposite edge portions of a workpiece by utilizing a plurality of pairs of electrodes to effect the electrolytic removal of material from opposite sides of the workpiece. Leading and trailing edge portions of the airfoils are formed by utilizing a plurality of relatively long narrow electrodes to effect the electrolytic removal of material to form slots between the major side surfaces of the airfoils and the remaining portion of the workpiece. During the electrolytic removal of material to form both the major side surfaces and the slots at the leading and trailing edge portions of the airfoils, an electrical potential is established beteen the electrodes and the workpiece and a flow of electrolyte is maintained between the electrodes and the workpiece. After the workpiece has been inspected, a base is formed in association with each of the airfoils.

Abstract: Disclosed are electrode assemblies which can be used to build a monoplanar membrane electrolytic cell suitable for the production of chlorine, alkali metal hydroxides and hydrogen having at least one central electrode assembly sandwiched between two end electrode assemblies with membranes therebetween to form a closed cell. Several of these resulting electrolytic cells can be connected in series or parallel to form electrolyzers very suitable for the electrolysis of a solution of sodium chloride or potassium chloride.

Abstract: A method of etching a submerged semiconductor material structure in which an electrically connected metal mask is utilized to electrolytically etch a semiconductive substrate without damaging the remainder of the structure.

Abstract: A quick-start electrolysis apparatus which is started up by means of an electrical supply circuit comprising regulating means for increasing the current intensity flowing through the apparatus in an exponential fashion as a function of time so that the ratio between the volume of gas and the volume of electrolyte is maintained constant.

Abstract: An improved apparatus for forming a plurality of airfoils or other articles includes a plurality of pairs of electrodes which are utilized in the electrolytic removal of material from opposite sides of a workpiece at a plurality of spaced apart locations to form side surfaces of a plurality of airfoils. The electrodes are constructed so that a group of airfoils is formed along each of a pair of opposite minor sides of a workpiece. In one specific instance, a plate having the configuration of a rectangle is utilized. This plate may have a size such that only one end portion of the plate will fit in a working chamber at a time. After a plurality of airfoils have been formed in one end portion of the plate, the plate is withdrawn from the working chamber and the opposite end portion of the plate inserted into the working chamber. In another specific instance, the workpiece included a support frame in which a plurality of partially formed airfoils are mounted.

Abstract: A novel electrolytic system, especially suitable for chlorate manufacture, is provided constituted by a novel electrolyzer and a novel reactor. The novel separate electrolyzer is designed for multicell assembly employing sheet metal electrodes and includes novel internal construction specially designed to hold the electrodes in place and to minimize internal liquor overflow between adjacent cells. The novel reactor provides suitable electrolyte retention time, temperature and product composition control respectively as well as gas separation with liquor level controlled for flooded electrolyzer system. The electrolyzer and the reactor are connected by liquor interconnection means.

Abstract: A process for brasquing cells for the fused electrolysis of alumina from the recovery of used brasques by treating the ground carbon-containing and refractory products of the base and walls by a known method with filtration of the insoluble constituents, distinguished by the fact that the base and lateral walls are covered by a heat-insulating bed formed by a mixture of carbon, NaF, CaF.sub.2, Al.sub.2 O.sub.3, Na.sub.2 SO.sub.4 and CaSO.sub.4, and by the fact that the cathode resting on the heat-insulating bed and containing the electrically conductive elements is formed from a brasque paste consisting of carbon, NaF, CaF.sub.2, AlF.sub.3, Na.sub.2 O and Al.sub.2 O.sub.3 associated with a binder which may be pitch.The qualities of the aluminum obtained from this cell are unchanged in relation to conventional processes.

Abstract: An apparatus is arranged over the bath of an electrolytic furnace containing molten aluminium.The apparatus has beams with tools which can be raised and lowered in a reciprocal manner to break-up the crust which forms on the top of the molten aluminium. Reservoirs containing alumina are also carried by the beams and serve to selectively charge quantities of alumina into the bath. Probes or lances are extendible and retractible in relation to the beams and serve to inject air into the molten aluminium.

Abstract: An electrode assembly comprising in combination:A. an elongated titanium bar of rectangular transversal cross-section having a pair of major planar opposed surfaces and a pair of minor planar opposed surfaces;B. a finned electrode consisting essentially of a plurality of elongated spacer bars of uniform width and thickness mounted in stacked parallel relationship on one of said major planar surfaces and a plurality of elements maintained in spaced parallel relationship throughout their length by said spacers, each element having a bottom flat wall of a width not less than that of the spacers and a pair of spaced outwardly sloping sidewalls each including an outwardly extending ledge; said spacers and elements being made of a metal selected from iron, copper, cobalt, nickel and alloys of these metals; andC.

Abstract: An inexpensive process for making a minute circular hole having a smooth peripheral edge in a thin wall of a metal article. A depression is formed on one surface of the wall so as to simultaneously form a projection on the other surface thereof. The apex of the projection is positioned in a spaced relationship to a cathode in an electrolyte. An electric current is then introduced between the projection, which serves as an anode, and the cathode, which acts to selectively and anodically dissolve the apex of the projection so as to form a minute hole in the wall.

Abstract: A pin for use in making the reflector includes an elongated .[.snank.]. .Iadd.shank .Iaddend.of regular polygon outline and a cube-corner formation at one end. The cube axis of the cube-corner formation is at an angle other than zero degrees with respect to the pin axis. A group of such pins are assembled into a pin bundle for use in making a mold insert for the reflector.