Powder Metallurgy Abrasion-Resistant Aluminium Alloys
Powder metallurgy abrasion-resistant aluminium alloys are alloys made to possess characteristics such as strength and wear resistance in order to be used in parts that are exposed to high levels of wear, such as gears and valves in engines or wheels and frames in bicycles. The hardness and strength of aluminium alloys are determined by their alloying elements and heat treatments. In general, aluminium alloys that have been alloyed with more than 3% silicon and with other alloying elements such as magnesium, manganese and copper, suffer less wear and tear when compared with pure aluminium alloys.
Powder metallurgy is a process for making metal parts and components involving the compression of metal powders. During the process, metal powders are compressed into their desired shape at elevated temperatures, resulting in parts with near-net shape accuracy. This process is known for its ability to produce complex parts with precise dimensions. Compared with other forming and fabrication processes, powder metallurgy offers the potential for higher material utilization and lower costs.
Powder metallurgy processes can also be used to create abrasion-resistant aluminium alloys. The heat treatment of powder metallurgy parts involves either atmospheric cycles or vacuum cycles, depending on the desired alloying elements. These alloying elements are usually included in the powder feedstock in the form of chips, cast or sputtered metal or metal oxides. During the heat treatment, the temperatures are increased to form the desired grain size and microstructure. The grain size control is important since small and uniform grain sizes provide improved wear resistance.
In order to maximize the wear resistance of the parts made from powder metallurgy abrasion-resistant aluminium alloys, additional treatments such as hardening, carburizing, quenching and tempering may be necessary. Hardening and carburizing are typically used to obtain a higher degree of surface hardness, whereas quenching and tempering are applied to enhance the underlying mechanical characteristics. Additionally, surface treatments such as plating, painting, polishing and anodic coating may be used to provide additional protection against wear.
Powder metallurgy abrasion-resistant aluminium alloys are widely used in many industrial and consumer applications. They are often used in high-stress components such as cylinders, engine blocks, pistons, gears and valve components. The wear-resistance they offer makes these alloys attractive for applications such as abrasive sand or grit blasting, flooring, law mowers and skateboards.
In conclusion, powder metallurgy abrasion-resistant aluminium alloys offer a unique combination of strength, wear resistance and affordability for a wide range of industrial and consumer applications. Various heat treatments and surface treatments can be applied to enhance the strength and wear resistance of the parts made from these alloys. As a result, they are often the ideal choice for components that require increased strength and durability in hostile environments.
