Stamping is the process in which a piece of flat sheet metal, in either blank or coil form, is fed into a stamping press where a tool and die surface forms the metal into a specific shape. Most press shops have the equipment to form steel, and most of those machines will suit aluminum. Die-design rules primarily developed for steel must be modified for forming aluminum alloys. Critical variables encountered with aluminum stamping are the formability of the aluminum blank, the geometry of the part and tooling and press setup, including lubrication and accurate control of blankholder pressure.
The advantages of using aluminum for your stamping products include ductility, aluminum has a low melting point which allows flexible formation throughout product design, making it ideal for the power storage, beverage container, battery, consumer electronic, pharmaceutical and decorative industries.
Aluminum is often used for solar technology and similar applications and is reflective of light and heat. Aluminum stamped products are also used in the aerospace, industrial, marine, medical, construction, automotive, lighting and electronic industries. Aluminum is recyclable without deterioration, making it highly sustainable. It is corrosion resistant because it generates a natural oxide coating and is tolerant to moisture and most chemicals.
Aluminum is also very lightweight and strong. With an excellent strength-to-weight ratio, it is critical to the automotive and aerospace industries. Other advantages are that it is non-magnetic, will not burn, increases in strength as temperature decreases, non-toxic, and a highly efficient thermal/electrical conductor.
Due to aluminum having low formability compared to steel, product design features such as radii, draw depths, wall angles, steps and transitions must be carefully selected as they all interact to affect the cost and quality of aluminum stampings.
Stamping machines must be designed carefully, especially if the components previously were produced for steel, to account for aluminum’s different properties. A thin layer of aluminum oxide forms on the sheet surface of aluminum that can break down during forming, and abrade cutting and forming tools. This oxide film, very hard, brittle and tightly adhering, tends to break. This will allow highly adhesive metal-to-metal contact, often requiring surface treatments to protect the tooling.
The stamping equipment can be categorized in two types. Mechanical presses and hydraulic presses. Mechanical presses have a mechanical flywheel to store the energy, transfer it to the punch and to the work piece. Hydraulic presses utilize a hydraulic system to deliver controlled force.
Full-service metal stamping shops have the capabilities to take your aluminum stamping project from the concept stages through full production. Custom stamping is important when the part you need isn’t readily available. Custom aluminum stamping can include die design services and die engineering services to customers. Die design services can eliminate wasted resources, improve quality and shorten turnaround time.