Weld metal material apparatus and method

Abstract

A solid weld-metal-producing material is formed by agglomerating weld metal material powder. An igniter may be integrally formed in or on the agglomerated weld metal material. In addition to typical components of a weld metal material mixture, such as a reductant metal and a transition metal oxide, the agglomerated weld metal mixture may include a binder material, such as sodium silicate. In addition to functioning as a binder to help hold the agglomerated weld metal material together, the binder material may aid in the exothermic reaction that occurs when the weld metal material is ignited. The agglomerated weld metal material may be made by mixing together a reductant metal powder, a transition metal oxide powder, and possibly a binder solution. A slurry of the components may be pressed together, for example, using a die and a ram, and then may be dried.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] This invention relates generally to welding apparatus and methods, and more particularly to apparatus and methods for forming weld connections, and for initiating self-propagating exothermic reactions, such as in the process of forming the weld connections. [0003] 2. Description of the Related Art [0004] Exothermic welding has become recognized as a preferred way to form top quality high ampacity, low resistance electrical connections. [0005] Exothermic welded connections are immune to thermal conditions which can cause mechanical and compression joints to become loose or corrode. They are recognized for their durability and longevity. The process fuses together the parts or conductors to provide a molecular bond, with a current carrying capacity equal to that of the conductor. Such connections are widely used in grounding systems enabling the system to operate as a continuous conductor with lower resistivity. [0006...

AI Technical Summary

Benefits of technology

The invention is a solid agglomeration that can produce molten weld metal when ignited. This agglomeration includes a metallic compound, a reducing agent, and a mechanical binder. The agglomeration can be made from a slurry that includes a liquid and powdered materials. When placed in a weld chamber, the agglomeration is ignited to produce molten weld metal, which then flows into the weld chamber to couple together the conductors. The invention also includes a device and method for producing molten weld metal material. The technical effects of the invention include a more efficient and compact way to produce molten weld metal, which can be easily transported and stored.

Problems solved by technology

Exothermic welded connections are immune to thermal conditions which can cause mechanical and compression joints to become loose or corrode.

The exothermic reaction produces a large amount of heat.

However, because of the starting powder's low ignition temperature and difficulties in handling and shipping, much effort has been made to find a reliable and low cost alternative ignition system for the exothermic material.

For a variety of reasons, but primarily because of power requirements, dependability, and cost, such devices have not succeeded in replacing the standard starting powder / flint gun form of initiating the self-propagating exothermic reactions.

In addition, there are other difficulties inherent with the welding apparatus and method described above.

Aside from the difficulties in handling and shipping the starting powder 40, there may be problems in handling and shipping the bulk exothermic material 36 itself.

Properly measuring the exothermic material 36 may be both time consuming and susceptible to error.

Further, the graphite molds utilized in prior art apparatuses, such as the mold 12 utilized in the welding apparatus 10 shown in FIG. 1, may be costly because of the amount of graphite involved, and because of the amount of machining need to produce the passages shown in the mold 12 of FIG. 1.

Finally, a process such as that described above produces undesirable residues on surfaces of the mold 12.

The residues require periodic cleaning of the surfaces of the mold 12, a labor-intensive process.

Even with periodic cleaning, the formation of the residues may reduce the operational life of the mold 12.

Finally, the cleaning itself may cause damage to the mold, also leading to reduced operation life of the mold 12.

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