What is Extruded Aluminum
An aluminum extrusion manufacturer transforms aluminum alloy into an amazing variety of useful products. Making the most of aluminum's malleability, the extrusion process creates shapes by heating a billet, or cylindrical log, of aluminum alloy to soften it and then forcing it under high pressure through a special steel die using a hydraulic press or ram. The end result is a piece of aluminum that will maintain the specific shape of the die.
When the extrusion emerges from the die, it must cool at specific rates to reach the proper hardness. Cooling can occur naturally or can be assisted by means of fans and water spray. The extrusion is pressed mechanically to straighten it and is then cut to specified lengths. Depending on the aluminum alloy, additional aging may be required for the extrusion to reach its optimal strength. The surface of the extruded aluminum parts can be finished in a variety of ways, including anodizing, painting and powder-coating. The aluminum extrusion process is excellent for creating customized parts for the automotive, aviation and construction industries, such as window frames, railings and aircraft parts.
There are two primary types of extrusion processes -- direct and indirect. In the direct extrusion process, the most common method used today, the softened aluminum billet is pushed by the ram through a stationary die to create the specified shape. The aluminum flows in the direction that the ram travels, creating friction between the billet and the container. The direct extrusion method is commonly used for softer alloys in the manufacture of solid aluminum bars and rods, and hollow tubes and sections. One advantage of the direct extrusion process is that long continuous lengths can be produced by adding successive billets to the flow.
Indirect extrusion involves holding the aluminum billet stationary while the die moves. The die, which is contained within the ram, presses against the metal and forces it to flow into the ram and acquire the shape of the die. The indirect method is typically used for the extrusion of harder alloys and, because no friction heat is produced in this method, there is less chance of surface tears and cracked edges.
Shape is often a determining factor in the ease with which an aluminum part can be extruded. Although all aluminum alloys can be extruded and a wide variety of shapes can be created, there are limiting factors which need to be considered when determining if a particular part can be extruded successfully. These include size, shape, alloy, tolerance, scrap ratio, extrusion ratio and tongue ratio.
Sapa Extrusion is one of the world's largest custom aluminum extrusion companies.
We are the North American leader in common alloy extruded aluminum products, offering the industry's most comprehensive product line. Sapa Extrusion provides extruded aluminum products in standard and custom shapes (solid, semi-hollow and hollows). Our standard and specialty rod and bar products, including ACC-U-ROD®, ACC-U-HEX, ACC-U-BAR®, ACC-U-PLATE®, and Jumbo Rod are favored by premium machinists throughout North America. We also provide industry-preferred standard, high fin and thin fin heat sinks and slip-resistant DIAMONDBACK® Systems.
Sapa Extrusions offers complete solutions for extruded aluminum products required by the automotive, mass transit, bridge decking, and solar/renewable energy industries, as well as many other industrial and consumer markets. Sapa has an extraordinary capacity for producing all standard and custom extruded aluminum shapes, sizes, alloys and tempers, by both direct and indirect extrusion, through our nationwide network of production and supply facilities.
Decades of experience enable Sapa Extrusion to offer solutions for virtually any unique application. We design and manufacture extrusion tooling using the latest technology and CAD/CAM design. Our expert staff of metallurgists and engineering, manufacturing, design and marketing specialists can provide everything you need to create your custom extruded aluminum products.