Erico International Corporation

David P Kovarik

Michael D Amos

James E Whetsel

Mark V Samas

Richard E Singer

Denis A Brosnan

George F Kub, Jr

Ginger Ortman

The invention provides a method and means of producing weld metal for use in joining two or more aluminum containing pieces. The method includes the steps of providing a novel mixture of reactants comprising silicon, a reducing agent, a metallic compound which is exothermically reduced by the reducing agent, and a filler metal that does not react with the metallic compound. The mixture of reactants is then exothermically reacted so as to form the weld metal for joining the metallic pieces. At least about 90 percent by weight of the weld metal is produced by the silicon and the filler metal and at least about 90 percent by weight of the weld metal has a chemical composition substantially similar to that of at least one of the metallic pieces being joined.

Aluminum welding process and mixture of reactants for use in such process

An improved thermite reaction containment vessel and method of using the same includes a filter assembly which serves to filter the gases evolving from the thermite reaction and reduce the amount of smoke, fume and the like by-products emitted. In one preferred embodiment the filter assembly comprises a primary filter and a secondary filter. An air gap may be provided between the primary and secondary filter so as to provide additional cooling of the gases before they enter the secondary filter. The invention further provides a remote electrical ignition system which is capable of igniting thermite reaction materials without the use of a starting material. The ignition system may include an ignition fuse having an aluminum core and an outer coating comprising palladium and ruthenium or hot wire.

Exothermic welding apparatus and method

Exothermic reaction mixtures are economically ignited remotely and electrically without the use of a low ignition starting material by creating a predetermined spark gap within a matrix of such mixture and then impressing a high energy spark across the gap through the use of a capacitor discharge circuit. The mixture is contained in a graphite or ceramic vessel or crucible and is supported over a tap hole or runner by a fusible metal disk. The material of the vessel is preferably graphite which is electrically conductive. In one form of the invention, an insulated wire with a bare tip is positioned just below the top surface of the mixture and the tip spaced a predetermined distance from the wall of the vessel. The capacitor discharge circuit is then employed to fire a high energy spark through a matrix of the material across the gap formed between the wire and vessel to initiate the reaction. In another form the spark gap may be established in a small cylindrical cartridge containing the material. The cartridge may be positioned through a hole in the side wall of the mold just below or near the top of the exothermic material so that it can be filled with the material from the main body of the exothermic material.

Exothermic welding and method

An improved thermite reaction containment vessel and method of using the same includes a crucible in which the exothermic material is contained and which is connected at its lower end via a tap hole to a weld chamber in which the parts to be welded are positioned. On top of the crucible is positioned a baffle assembly which includes a plurality of expansion chambers which allows the escaping gas to expand and be reduced in velocity. As the gases move from one expansion chamber to the next the gases change direction. The expansion, direction change and the large surface area of the baffle assembly allows the gases to slow and cool before being exhausted leaving behind molten metal spatter or flame and greatly reducing the amount of smoke exhausted since particulate matter is accumulated on the baffle interior surface. Several forms of baffle assembly are disclosed using inverted stacked metal cups. The baffle assembly may be used in conjucntion with a filter assembly and remote electrical ignition or without a filter assembly and conventional starting material, with such matrial being ignited through the top of the baffle assembly.

Exothermic welding apparatus including a baffle cover assembly

A self-contained and sealed package of exothermic welding material includes a cup-shape disposable ceramic container for such material which is closed at the top with a heat consumable cap. The bottom of the container includes a tap hole, the lower end of which is also closed with a formed cup-shape heat consumable disk. An insulated wire pair extends along an axial groove in the exterior of the container and through a radial groove through the lip of the cup beneath the cap. The end of the wire pair within the container has the insulation removed to form a spark gap which end extends at an angle away from the interior of the container and is embedded in the exothermic material. The ends of the wire pair outside the container have the insulation removed to a greater extent so that the wires can readily be bent and connected to power unit for generating a high energy spark at the gap. The package is mounted unopened on a seat on a refractory mold above a weld cavity which contains the parts to be welded and a hinged baffled mold cover closed. The wire pair having been bent to extend beneath the cover is connected to the spark generator. When the exothermic material is ignited the heat causes the package cap to be consumed and as the reaction proceeds the disk is consumed permitting the molten metal produced by the reaction to drop into the weld cavity. A major portion of the slag formed in the reaction remains in the ceramic container and is disposed of with the container while the refractory mold is reused.

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Eastlake, OH, United States of America

David P Kovarik