Post-machining processes
After machining an aluminium part, there are certain processes that you can carry out to enhance the physical, mechanical, and aesthetic features of the part. The most widespread processes are as follows.
Bead and sand blasting
Bead blasting is a finishing process for aesthetic purposes. In this process, the machined part is blasted with tiny glass beads using a highly pressurised air gun, effective removing material and ensuring a smooth surface. It gives aluminium a satin or matte finish. The main process parameters for bead blasting are the size of the glass beads and the amount of air pressure used. Only use this process when the dimensional tolerances of a part are not critical.
Other finishing processes include polishing and painting.
Besides bead blasting, there is also sandblasting, which uses a high-pressure stream of sand to remove material.
Coating
This involves coating an aluminium part with another material such as zinc, nickel, and chrome. This is done to improve the parts processes and may be achieved through electrochemical processes.
Anodising
Anodising is an electrochemical process in which an aluminium part is dipped in a solution of diluted sulphuric acid, and an electric voltage is applied across the cathode and anode. This process effectively converts the exposed surfaces of the part into a hard, electrically non-reactive aluminium oxide coating. The density and thickness of the coating created is dependent on the consistency of the solution, the anodising time, and the electric current. You may also carry out anodisation to colour a part.
Powder coating
The powder coating process involves coating a part with colours polymer powder, using an electrostatic spray gun. The part is then left to cure at a temperature of 200°C. Powder coating improves strength and resistance to wear, corrosion, and impact.
Heat treatment
Parts made from heat-treatable aluminium alloys may undergo heat treatment to improve their mechanical properties.
Applications of CNC machined aluminium parts in industry
As stated earlier, aluminium alloys have a number of desirable properties. Hence, CNC machined aluminium parts are indispensable in several industries, including the following:
Aerospace: due to its high strength to weight ratio, several aircraft fittings are made from machined aluminium;
Automotive: similar to the aerospace industry, several parts such as shafts and other components in the automotive industry are made from aluminium;
Electrical: having high electrical conductivities, CNC machined aluminium parts are often used as electronic components in electrical appliances;
Food/Pharmaceutical: because they do not react with most organic substances, aluminium parts play important roles in the food and pharmaceutical industries;
Sports: aluminium is often used to make sports equipment such as baseball bats and sport whistles;
Cryogenics: aluminium’s ability to retain its mechanical properties at sub-zero temperatures, makes aluminium parts desirable for cryogenic applications.
Post time: Dec-27-2021