Aluminium

Aerospace Industry: Used in aircraft frames, wings, and engine components due to its lightweight and high strength-to-weight ratio. Automotive Industry: Applied in car bodies, wheels, engine blocks, and heat exchangers to reduce weight and improve fuel efficiency. Construction Sector: Extensively used in window frames, roofing, curtain walls, and structural panels because of its durability and corrosion resistance. Electrical Industry: Commonly used for power cables, conductors, and electrical bus bars owing to its excellent electrical conductivity.

The hardness of aluminium ⚙️ varies widely depending on its purity and alloy composition. Pure aluminium is quite soft, with a Brinell hardness of about 15 to 30 BHN, making it easy to shape and form 🧩. When alloyed with elements such as magnesium, silicon, copper, or zinc, its hardness increases significantly 💪. For instance, the popular 6061-T6 aluminium alloy has a hardness of around 90–100 BHN, offering a good balance between strength and machinability 🛠️. In contrast, 7075-T6 aluminium, known for its high strength, reaches 130–150 BHN, comparable to mild steel 🔩. Cast aluminium alloys like A356 typically show moderate hardness in the range of 60–80 BHN. Overall, aluminium’s hardness can be enhanced through heat treatment (like T6 tempering), which improves strength while maintaining its excellent lightweight and corrosion-resistant properties ✨.

Solution Heat Treatment: The alloy is heated to a specific temperature range (typically 500–550°C) to dissolve the alloying elements uniformly into the aluminium matrix. It is then rapidly quenched (usually in water) to retain the elements in solution. This process increases the potential for strengthening during aging. Quenching: The hot aluminium is quickly cooled to lock the alloying elements in a supersaturated solid solution. This step is crucial to prepare the metal for aging and to avoid coarse precipitation. Aging (Precipitation Hardening): After quenching, the material is either naturally aged at room temperature (T4 condition) or artificially aged at elevated temperatures (150–200°C) for several hours (T6 condition). This allows fine precipitates to form, which significantly improve hardness and tensile strength 💪. Annealing: Used to relieve stresses, improve ductility, and restore workability after cold working. The material is heated to 300–400°C and then slowly cooled.

Solution Treatment: The aluminium alloy is heated to a high temperature (typically 500–550°C) to dissolve alloying elements such as copper, magnesium, silicon, or zinc into a solid solution. Quenching: The heated alloy is rapidly cooled (usually in water) to retain these alloying elements in a supersaturated solution. This step prepares the alloy for hardening. Aging (Precipitation Hardening): The quenched alloy is either: Naturally aged (T4 condition): Allowed to harden at room temperature. Artificially aged (T6 condition): Heated again at 150–200°C for several hours to form fine, evenly distributed precipitates. These precipitates hinder dislocation movement in the crystal structure, resulting in increased strength, hardness, and wear resistance 💪. Cold Working (Optional): In some alloys, further hardening can be achieved through strain hardening (work hardening) by rolling, drawing, or pressing at room temperature.

Pre-Weld Preparation: Aluminium forms a thin oxide layer (aluminium oxide) that melts at a much higher temperature (~2050°C) than the base metal (~660°C). This oxide layer must be removed before welding using a stainless-steel brush or chemical cleaner. Proper cleaning ensures good fusion and prevents porosity. Welding Methods: TIG (GTAW – Gas Tungsten Arc Welding): The most common method for aluminium welding. It provides precise control and clean welds using argon or helium shielding gas and a non-consumable tungsten electrode. MIG (GMAW – Gas Metal Arc Welding): Suitable for thicker aluminium sections. It uses a consumable aluminium wire electrode and shielding gas (argon or argon-helium mix) for faster welding. Resistance Welding and Friction Stir Welding: Used for specific industrial applications, especially in aerospace and automotive sectors. Filler Materials: Common aluminium filler alloys include: ER4043 – for general-purpose welding, offers good fluidity and crack resistance. ER5356 – used when higher strength or color matching after anodizing is needed. Precautions: Aluminium conducts heat rapidly, so distortion and burn-through can occur; controlled heat input is essential. Preheating thick sections (around 150–200°C) may improve weld penetration. Use clean, dry shielding gas to prevent contamination and porosity.

Ease of Machining: Aluminium cuts very easily compared to steels and other non-ferrous metals. It allows high cutting speeds and feed rates, which improves productivity. Its low hardness reduces tool wear, making it ideal for CNC machining, drilling, milling, and turning. Chip Formation: During machining, aluminium produces continuous, soft chips that are easy to manage. Using sharp cutting tools and proper chip breakers helps prevent chip clogging and ensures smooth cutting. Tooling: Carbide-tipped or high-speed steel (HSS) tools are commonly used. Tools must be very sharp and have large rake angles to avoid material build-up on the cutting edge. Coated tools (like TiN or diamond coatings) can further improve performance and finish. Surface Finish: Aluminium can achieve excellent surface finishes without additional polishing. The smooth finish also improves corrosion resistance and aesthetic appearance. Lubrication and Cooling: While aluminium doesn’t always need lubrication, coolants or light cutting oils help improve tool life and chip removal, especially in high-speed operations.

We are a leading dealer, supplier, stockist, and trader of Aluminium and its various grades, catering to the diverse needs of industries across India. Our range includes Aluminium sheets, plates, rods, bars, pipes, and extrusions, all sourced from trusted manufacturers ensuring premium quality and consistency.