Without the active use of aluminum alloy products, it's hard to imagine any serious manufacturing. This is the construction sector, industry, and transportation manufacturing. The industrial application of aluminum is not coincidental, as its characteristics are truly unique — it combines strength and light weight, resistance to corrosion, and the effects of aggressive environments. When other chemical elements are added to a material to obtain new properties or enhance existing ones, aluminum alloys are produced.
The history of aluminum began not so long ago, compared to other metals. Aluminum was first obtained by Hans Christian Ørsted through the electrolysis of alumina in 1825. The first known industrial production of aluminum began in 1856 at the factory of brothers Charles and Alexandre Tissier in Rouen.
Main Types of Aluminum Alloys
When studying the types of aluminum alloys, one can see two main categories. Castings are created based on blanks of the required shape, into which liquid metal is poured. Deformable alloys are ingots that are subsequently pressed, stamped or rolled. The most common ones look like this:
- Aluminum-zinc-magnesium with enhanced strength and ease of processing.
- Aluminum-magnesium alloys with enhanced plasticity and good weldability. It is necessary to protect against the spread of corrosion.
- Aluminum-silicon alloys used for the production of cast parts in high-load mechanisms.
For bushings, bearings, and other parts with increased friction, an aluminum-copper-silicon alloy is used.
The classification of alloys is carried out according to different markings, depending on the groups of countries. International labeling describes alloys in series 1000, 2000, and 3000, where series 1000 indicates 99% purity, 2000 signifies copper alloying, and 3000 refers to alloys alloyed with manganese. There are a total of 8 such episodes.
Factors in Choosing an Aluminum Alloy
Understanding the load that the aluminum alloy product will be subjected to will make it easier to select its characteristics. The selection of aluminum alloys begins by comparing their strength. There are low-strength alloys with a specific strength of 150 to 200 MPa, medium-strength alloys with indicators of 200-340 MPa, and high-strength alloys ranging from 340 to 400 MPa. A product in any of the listed categories achieves its maximum strength only when heat treatment is performed. Additionally, the processes of hardening and ageing affect strength.
Each specific industry has its requirements for alloys. For example, the construction sector implies that the component will have corrosion resistance and weldability. For shipbuilding, corrosion resistance is needed specifically in seawater or freshwater. The motorcycle manufacturing industry requires heat resistance, thermal conductivity, and vibration resistance.
Comparison of popular aluminum alloys
In the construction sector, profiles from the 6XXX series are most commonly used. The initial average strength can be easily increased through subsequent heat treatment. The mechanical properties of alloys are as follows:
- 6061 - strong, easy to machine, good thermal conductivity.
- 6063 — smooth surface, suitable for structures where high strength is not required.
- 6082 has the highest extrudability, increased strength after heat treatment, and corrosion resistance.
- 6005 — high strength.
The use of alloys of this type specifically for construction is not accidental. The products are easy to fix for welding, easy to shape as needed, and they initially have a high level of corrosion protection. But looking at popular aluminum alloys and comparing them based on key indicators, it makes sense to compare them by tensile strength, elongation, and yield strength:
- The alloy 6063 has the highest extrudability. The minimum strength limit here is 205 MPa, the yield strength is 170 MPa, and the elongation is 8%. The increased concentration of magnesium content allows the products to be used in structures with low load-bearing requirements.
- Alloy 6082 is suitable for the installation of windows, doors, and facades, as it has the highest strength indicators. Characteristics: the minimum tensile strength is 310 MPa, the yield strength is 270 MPa, and the elongation percentage is 7%.
- Alloy 6061 is similar to 6082 in terms of application, but it has slightly lower ductility and strength. The minimum values are 260 for strength and 240 for ductility, while the elongation coefficient is 8%.
When buying profiles, there is a higher chance of encountering the 6063 brand.
Examples of the use of alloys in various industries
Aluminum alloys are most actively used in construction, as they are a versatile option for producing durable frames, cladding, and structural components. There is a request for high-quality aluminum alloy for further production of containers and vessels. The material is used in the food industry, where an alloy resistant to acids is required. The automotive industry also needs aluminum, as it is essential for creating vehicle parts.
Aluminum in aviation is found not only in the components of the fuselage or internal elements. The electrical engineering industry uses aluminum in the production of cables, wires, communications, and household appliances. It is easy to find it in roofing material, as it takes paint well and protects the main structure from weather factors. It is impossible to set up heating without encountering aluminum elements, as they are needed both for the heating devices themselves and for the production of fans, radiators, and pipes.
Conclusion and recommendations on the choice of alloy
Aluminum is rightly considered the most important and in-demand lightweight metal. There is no equivalent in terms of the combination of strength and lightness. The selection of aluminum alloys is based on the specific industry for which the material is being chosen, as the requirements in the automotive, electrical engineering, or construction sectors are not the same. Recommendations for choosing an alloy often include a visual comparison of two or more options against each other. It is necessary to analyze the main parameters, including thermal conductivity, yield strength, machinability, melting temperature, and others.
The optimal alloy can be found by understanding the designations in the labelling. Various types of markings are used, but the most commonly encountered is the international standard ISO 209-1. The first digit indicates the belonging to the group of used alloying elements. They give the alloy unique characteristics and properties. Manufacturers can provide thermal strengthening properties, which are required for the aviation sector, enhance resistance to moisture and corrosion, ensure weldability, and offer other sought-after options. In addition to alloying, various methods of heat treatment are used, namely quenching, annealing, or ageing.
