Thermit Welding Material
The thermit welding process is the result of fusion caused by a chemical reaction that occurs due to the difference in free energy between aluminum and metal oxide.
The heat generated by this difference is enough to produce liquid steel or any other metal without the use of external energy.
It happens without stress or under stress. The use of filler metal is optional.
All components of the thermite method are used as powder or granules.
Once the reaction is initiated by an external heat source, aluminum will reduce the oxygen in the metal oxide, which will result in liquid superheated alumina.
Due to the different densities of these two components, they will separate automatically, and the liquid metal can be used for alloys, special metals or a variety of welding applications.
Since the turn of the century, the thermic process has been used to connect train tracks and other transportation industry applications.
Examples of thermit welding
Key definitions:
Crucible: The chemical reaction of the thermite occurs in a container called a crucible
Mixture: A mixture of finely divided aluminum, metal oxides, and any required alloy metals
Mold: This mold is formed around the parts that need to be welded. The pattern receives molten metal.
Reaction: A chemical reaction between aluminum and metal oxides. The reaction produces alumina slag and overheated molten metal.
The thermit material is a mechanical mixture of metallic aluminum and processed iron oxide.
Molten steel is produced by thermite reaction in a crucible lined with magnesium.
At the bottom of the crucible, burn a magnesite with a magnesite thimble inside.
This thimble provides a channel through which molten steel is discharged into the mold.
The hole through the thimble is blocked with a tap, and the tap is covered with fireproof gaskets and refractory sand.
Charge by placing the correct amount of well-mixed thermite material in the crucible.
Process
When preparing the joint for thermit welding, the parts to be welded must be cleaned, aligned, and firmly fixed in place.
If necessary, remove the metal from the joint to allow the thermite metal to flow freely into the joint.
Then make a wax pattern around the joint of the size and shape to be welded.
A mold made of refractory sand is built on wax patterns and connected to keep the molten metal after it is poured.
Then heat the sand mould to melt the wax and dry the mold. The mold should be properly vented to allow the gas to escape and allow the proper distribution of the thermite metal at the joint.
Sand Mould
