Machining is a general term that encompasses a range of manufacturing processes, such as:
- milling;
- stamping;
- welding;
- drilling;
- thread cutting;
- thermo drilling with subsequent thread cutting;
- engraving, etc.
There are also several types and methods of machining, such as CNC machining, Swiss turning, vertical and horizontal milling, and electrical discharge machining.
Aluminum profiles are easily subjected to various methods of mechanical impact/processing. At the same time, the cost of the tools used in such processes is cheaper than, for example, those for steel, while aluminum is processed at a significantly higher speed than steel and many other materials.
One of the important properties of aluminum profiles is the presence of complex cross-sections to perform various functions. Thanks to this, it requires only minimal processing, which optimizes machining costs compared to other materials.
The mechanical processing of aluminum profiles can be carried out both before and after the application of a protective decorative coating. This is determined by the technical requirements imposed on the finished product or part.
How is aluminum processed in each of these processing methods?
Milling is a machining process that uses rotating cutting tools to remove excess material from a workpiece. Milling equipment can have a vertical or horizontal configuration; vertical machines are ideal for a small number of simple aluminum parts, while horizontal machines are better suited for a large number of complex aluminum parts.
Stamping involves placing profiles in a press. In the press, the tool and the surface of the die shape the metal into the desired form. Stamping, bending, embossing, debossing, and flanging are all stamping methods used for shaping metal.
Welding aluminum is a process in which heat and pressure are used to join two components made of aluminum or aluminum-based alloys. Compared to welded joints made from other materials, such as steel, aluminum welded joints do not exhibit the same level of strength as solid products. Thus, it is extremely important to choose the right base material and welding technique to form a strong bond between aluminum parts. In addition, it is important to consider the storage conditions of aluminum, as well as the cleaning of the base material before the welding process.
Types of aluminum welding
Typically, welding methods are similar to those used for welding steel sheets, taking into account the chemical properties of aluminum.
Gas tungsten arc welding
This is the most common method of welding aluminum. This method is also known as tungsten inert gas welding. This method does not require mechanical wire feeding, which frees you from issues related to feeding problems. One of the reasons for the popularity of this method is that it creates a smooth and clean weld seam. This method is eco-friendly, as the work area is hardly polluted.
Gas arc welding
This welding uses a wire electrode that is continuously fed into the base of the weld joint. The wire is protected by an inert gas and, in some cases, a gas mixture to prevent hydrogen absorption. This method is often dirty due to the traces of tiny metal balls that remain as a result of using the spraying method.
Arc welding
Arc welding is the first of the open welding methods. This technique uses a power source to melt and join aluminum sheets. Despite being the most cost-effective type of aluminum welding, it should only be performed by an experienced welder.
Resistance welding
When working with aluminum, contact welding is also possible. However it can be problematic due to the thermal conductivity of aluminum. To complete the welding, you will need to use special tips, and welding equipment, and spend time preparing with consideration of the welding alloy parameters.
Electron-beam and laser welding
Laser welding provides high specific power, which is great because it prevents cold starts. However, both laser and electron beam welding have their drawbacks. In laser welding, the main task is the light reflectivity. Porosity is also a concern, but with proper optimization of the protective gas, it can be prevented.
Electron beam welding is more controllable. This is done in a vacuum, so there is no need to worry about porosity, and light is not used as an energy carrier here.
Drilling
Drilling is a mechanical process that uses a drill to cut a hole with a circular cross-section in hard materials.
Drilling aluminum should not cause any problems if you follow some simple rules.
Aluminum is a soft metal with a low melting point of 660 degrees Celsius (for comparison, stainless steel has a melting point of 1510 degrees Celsius). Due to its low melting point, it is very important to minimize heat buildup as much as possible during drilling. Otherwise, the melted aluminum will stick to the drill. Therefore, the best choice for drilling aluminum would be a cobalt drill bit, which dissipates heat faster and helps reduce heat buildup. The next factor that will facilitate this process is the correct choice of drilling speed. The recommended drilling speed for aluminum ranges from 200 to 300 RPM. The application of excessive pressure is another way to generate heat, so it should be avoided. Moreover, it is important to remember that lubrication is vital for maintaining a low temperature. A good lubricant for drilling will reduce friction between the drill and the metal, which minimizes heat buildup.
Thread cutting
Thread cutting is a machining process for creating threads on the outer surface of a cylinder or the inner surface of a hole. The tools used for cutting threads are a die for thread cutting and a screw insert. If we are talking about mass production, then this process is called cold or hot forming.
Thermal drilling followed by threading.
Thermal drilling is a technique for creating holes in metals that is the most cost-effective and extremely high-performance method of fastening metals. In industrial manufacturing, especially in the automotive industry, there are many types of connections between various parts made from different types of materials and varying thicknesses. For these purposes, it is advisable to use the connection method based on thermal drilling technology. By using new friction technologies, we can reduce production time, improve the quality of connections, offer automation for certain types of operations, optimize economic costs, and protect the environment.
Engraving
Engraving is the process of applying a design, inscription or marking onto a hard, typically flat surface by cutting away a microscopic top layer from the surface of the metal. Engraving can be non-contact (laser application) or mechanical.
Laser engraving can be either relief, where the upper micro surface is removed and a depression remains on the surface, or flat, where the metal simply changes color under the influence of the laser.
In mechanical engraving, metal is processed using "contact" technologies such as diamond engraving, drilling, sandblasting, and others.
