Other

Martin Marietta Corporation

Commonwealth Aluminum Corporation

Comalco Aluminum Limited

Martin Marietta Aluminum Inc.

Radon Appliances, Inc.

Douglas W Townsend

Larry G Boxall

Dennis C Nagle

Arthur V Cooke

William M Buchta

Duane O Terry

A metal bolt or cap screw fastener has a head, a shank of reduced cross section and a threaded portion, which fastener is configured to be manufactured using cold forming automatic bolt making machines of concurrent configuration. The reduced cross section shank provides additional elastic stretch and reduces stress throughout the fastener upon application of external joint parting loads, as compared to conventional fasteners with nominal diameter shanks. The inventive fastener has at least three straight longitudinal ribs along the length of the reduced cross section shank. The longitudinal ribs extend laterally outward from the surface of the shank a distance substantially corresponding to the fastener nominal diameter so as to center the fastener within round holes. During cold forming, the fastener shank diameter is made to the same or somewhat larger diameter than the not yet threaded part of the bolt.

Threaded fasteners with ribbed shanks

This invention relates to a process of electrowinning molten aluminum from alumina dissolved in molten fluoride salts which is essentially cryolite. More specifically the process relates to the treatment of aluminum reduction cell drained solid cathode surfaces to protect them while they are wetted by molten aluminum metal. This process produces aluminum wetted protective coatings composed of titanium diboride and titanium carbide and other refractory metal borides and carbides on top of a carbon-titanium diboride materials layer on the cathode surfaces from supersaturated dissolved elements in electrowon aluminum. The resulting protective coating is resistant to erosion, chemical attack, and penetration by molten aluminum metal, sodium, and cryolite electrolyte contained in that cell.

Supersaturation coating of cathode substrate

The invention relates to a process of electrowinning molten aluminum from alumina dissolved in molten fluoride salts which are essentially cryolite. More specifically the process relates to placing refractory metal raised cathode structures in aluminum reduction cells and treating the raised cathode surfaces to coat them with refractory metal borides. This process deposits coatings composed of titanium diboride and other refractory metal borides on titanium and other refractory metal cathode structures from supersaturated elements dissolved in electrowon molten aluminum. The refractory metal boride coatings are resistant to penetration by the molten aluminum metal.

Coating of cathode substrate during aluminum smelting in drained cathode

This invention relates to a process for electrowinning molten aluminum from alumina dissolved in molten fluoride salts which are essentially cryolite. More specifically the process relates to the treatment of aluminum reduction cell drained solid cathode surfaces to make them wetted by molten aluminum metal. This process deposits a coating composed of titanium diboride and titanium carbide on the solid cathode surfaces from supersaturated dissolved elements in electrowon aluminum. The electrowon aluminum wets the coating on the cathode. The coating makes the cathode surfaces resistant to erosion, chemical attack and penetration by the molten aluminum metal, sodium and cryolite electrolyte contained in that cell.

Supersaturation plating of aluminum wettable cathode coatings during

A protective system (10) is provided for preventing deleterious gases from entering the internal atmosphere (34) of a building structure (12) derived from surrounding ground environments (14 and 18). An enclosure (24) is mounted above a sump (26) containing a sump pump (30) for discharging liquid (32) to an external environment (22) when taken with respect to building structure (12). Mounted adjacent to the enclosure (24) is a fan mechanism (52) for drawing a partial vacuum in an enclosure chamber (28 and 28'). The fan mechanism (52) is in fluid communication with a gas discharge pipe (58) for passing or displacing contaminated gas into the external atmosphere (22). Radon contaminated gas passes through perforated drainage pipes (48) into sump (26) and due to the negative pressure gradient created by fan mechanism (52), radon contaminated gas is displaced through gas discharge pipe (58) to the external atmosphere (22). The enclosure (24) and couplings thereto are formed in substantially airtight relation and thus, the contaminated gas being drawn from enclosure chambers (28 and 28') is not directed into the building structure internal atmosphere (34), but displaced directly to the external atmosphere (22).

Protective system

An electrolytic reduction cell for the production of aluminum having a slotted cathode collector bar. The slots are filled with insulating material thereby directing the electrical current flow through the cathode collector bar in a manner which reduces the horizontal current components in the cell.

Slotted cathode collector bar for electrolyte reduction cell

Aluminum cells may be produced having cathode surfaces which are wetted by aluminum, said surfaces comprising Refractory Hard Materials in a non-graphitized carbon matrix. Such cells may utilize inclined or drained cathodes as well as non-consumable anodes.

Aluminum wettable cathode material for use in aluminum reduction cell

Aluminum cell having aluminum wettable cathode surface

This invention relates to an improved coating composition for application to aluminum cell cathodes, wherein said composition comprises a Refractory Hard Material, and a thermosetting resinous binder system. The resinous binder system is characterized by a char yield greater than 25 percent, while the coating composition exhibits expansion characteristics such as to adhere to a cathode block at temperatures up to and including those normally encountered in the operation of an aluminum cell. The ablation rate of the carbon system utilized is essentially equal to the combined wear and dissolution rate of the Refractory Hard Material in an aluminum cell environment.

Aluminum cell cathode coating composition

This invention relates to a method for the application of a coating composition containing Refractory Hard Material to a cathode substrate to prepare an aluminum wettable cathode surface. A mixture of Refractory Hard Material and carbon system is applied to a cathode substrate, cured and carbonized to a non-graphitized carbon matrix containing Refractory Hard Material, characterized by strong bonding of said matrix to said substrate and an ablation rate of said carbon matrix similar to the combined rate of wear and dissolution of the Refractory Hard Material.

Aluminum cell cathode coating method

The application of a Refractory Hard Material coating composition to selected areas of the surface of an aluminum cell cathode permits tailoring or control of ledge formation during cell operation. Cell voltage improvements are also noted, resulting in more efficient cell performance.

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Glen Burnie, MD, United States of America

Douglas W Townsend