We use and come across aluminum products every day. It is present everywhere around us in one form or another. All these applications of aluminum in our lives and various manufacturing industries around the world are a product of aluminum fabrication. However, even though it is so readily used today the process for producing aluminum products is not an easy one due to the complex method of extracting aluminum through raw materials.
Creating aluminum consists of two processes. Refining Bauxite ore and smelting of the product of the refining process, the aluminum oxide, to separate pure aluminum from the oxygen.
The first step, Bauxite is crushed using machines and then mixed with caustic soda. The mixture is processed to give out a slurry comprising of ore particles. It is then heated and applied heavy pressure to for several hours until the compounds containing aluminum have dissolved. The resulting product is purified using a settling tank and filtering cloth. Seed crystals containing alumina hydrate are then added to the precipitation tanks where they bind with dissolved alumina and grow into larger crystals which are then removed, washed and heated to get rid of water particles.
The second step, a reduction pot with the carbon lined bottom and carbon rods suspended above it are used. The carbon rods help produce an electric current through the mixture. The current when passed through forces the oxygen and aluminum to separate. The oxygen attracted to the carbon rods becomes carbon dioxide while pure aluminum reaches the bottom of the container.
Once the raw material has been procured through the extraction or the recycling process different techniques are applied to shape it into useful parts that will be used to form the final product. Cutting, grinding, shaping, drilling and other such techniques are then used to form whatever is required. Examples of Metal Fabrication methods are:
During fabrication, a product goes through the following:
Aluminum can be sawed at higher speeds than steel. Clean cuts and extrusions can be made without forming any burrs.
Small chips and remaining burrs are removed from the extrusions in this process.
High powered tools with high cutting speeds are used to cut or shape the aluminum.
Drilling is carried out at high speed using sharpened tools so that less pressure is required and a better result can be obtained.
Aluminum is rotated in special lathes to give it shape in the turning process.
Taps are used to make internal or external threads as required.
Usually, punch and die of hardened tool steel are used to shear the aluminum metal as necessary.
Insulation techniques like thermal break are applied for products where low heat transfer is required such as windows.
Aluminum fabrication is a complex process where different methods are employed based on different products and their requirements. Just a few of the techniques have been mentioned here. Others include hydroforming, plastic forming, different types of bending such as roller bending, draw bending, stretch bending etc.