Aluminum extrusion and aluminum welding go hand in hand. Extrusion allows for a variance in the thickness of the wall in whatever aluminum object that was created by the extrusion process. Because the wall can have a varying thickness throughout the object, that object can have something called a vee groove.
What is a vee groove? A vee groove is a V-shaped formation in a piece of metal. The vee groove facilitates performance of a welding process. The welding process is used to create a bond between two different metals.
If a vee groove exists in an aluminum part, that aluminum part can be welded to a different metal part. Aluminum welding is used to melt one metal part, a part that should be joined to another metal part. The heat from the welding device creates a small pool of liquid. That liquid forms a puddle in the vee groove.
The hot liquid is used to bond two different metals. The hot liquid in the vee groove coalesces around a section of each of the two different metal parts. Once the molten material has hardened, the metal objects have been fused together.
Coalescence permits the joining of aluminum and a second metal, but it is not the only scientific property that can aid formation of a metal to metal bond. Not every fusion of aluminum and a second metal has resulted from aluminum welding. Sometimes that fusion is produced by a process called brazing.
Brazing relies on the properties of capillary action. As in aluminum welding, in brazing a section of metal must be heated to the point where it enters a liquid state. That molten metal is then distributed on the close-fitting metal parts. After the liquid metal hardens, then the metal parts are firmly fused together.
Both aluminum welding and brazing can call for exposure of metals to a good deal of heat. Sometimes a metal worker does not want to expose a piece of metal to very high temperatures. If that piece of metal should be joined to another metal, then what process can the metal worker use?
When a metal worker faces the above-mentioned problem, then he or she needs to use a process called soldering. Soldering takes advantage of the low melting point of one metal, a metal different from the two metals that need to be joined together. Liquid from a metallic substance with a low melting point is used to create an adherence between two different metal parts.
Aluminum alloys do not always need to be joined by welding, brazing or soldering. Sometimes aluminum alloys have been held together by adhesive bonding. Sometimes mechanical fasteners clasp onto two connected, aluminum alloys. Sometimes bolts, nuts or rivets are used to join together two different aluminum alloys.All of the above methods create a strong metal to metal bond.
All of the above methods benefit from the tensile strength of aluminum. All of the above methods use to advantage a characteristic of the extrusion process.
Both aluminum welding and the other metal joining methods put demands on an extruded metal object. Still, an object created by the extrusion process can be made thickest at the points where it receives the most pressure.
Author: Patrick T. Tremblay
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