Chemistry – Metals - Reactivity series | e-Consult
Metals - Reactivity series (1 questions)
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Aluminium is frequently used in the production of alloys because alloying can significantly enhance its desirable properties, overcoming some of its limitations. While aluminium is lightweight and corrosion-resistant, it is relatively soft and has a lower strength compared to other metals. Alloying with other elements can address these shortcomings.
Modifying Properties through Alloying:
- Increased Strength and Hardness: Adding elements like copper, magnesium, or zinc can increase the strength and hardness of aluminium alloys. This is achieved by disrupting the regular arrangement of aluminium atoms in the crystal lattice, making it more difficult for dislocations (which cause deformation) to move.
- Improved Corrosion Resistance: Certain alloying elements, such as chromium, can further enhance the corrosion resistance of aluminium alloys, particularly in aggressive environments.
- Enhanced Machinability: Alloying with elements like silicon can improve the machinability of aluminium alloys, making them easier to shape and form.
- Increased Melting Point: Alloying can raise the melting point of aluminium alloys, making them suitable for high-temperature applications.
Examples of Aluminium Alloys and their Applications:
| Alloy Name | Composition (approximate) | Applications |
| Aluminium-Magnesium Alloy (50%) | 50% Mg, 50% Al | Aircraft construction, automotive parts, transport containers. Increases strength and weldability. |
| Aluminium-Copper Alloy (2%) | 2% Cu, 98% Al | Electrical wiring, cookware. Improves strength and conductivity. |
| Aluminium-Silicon Alloy (5%) | 5% Si, 95% Al | Engine blocks, automotive components. Improves machinability and strength. |
In summary, alloying allows engineers to tailor the properties of aluminium to suit specific applications, making it a versatile and widely used material.