Aluminum extrusion operations vary from project to project, depending on the part and production specifications. However, in general, they follow the same basic process, which includes the following steps:
- Determining the customer’s profile.The customer provides Richardson Metals with a drawing of the profile that needs extruded. At this point, it is determined if we can produce the design and meet the customers specifications and tolerances. Any part that Richardson Metals makes for the customer must fit inside a 4.5” diameter circle and weigh no more than 2.5 pounds per foot. Once the design has final customer approval, the die is made.
- Cutting the aluminum into billets.Once the dies are produced, production can then proceed to the extrusion process. The first step is cutting the aluminum into billets (i.e., cylindrical blocks of metal)
- The billets are then pre heated to between 850° F and 925° F, which is hot enough to soften the metal but not hot enough to reduce it to a molten liquid state. While the operating temperature can be anywhere within that range, it must be consistent throughout the operation. Otherwise, the end-product may have non-uniform cross-sectional areas.
- Transferring the billets to a loader.Once the billets are heated, they are placed on a loader and lubricated to prevent them from sticking to the extrusion equipment.
- Extruding the billets.After placement in the loader, the billets undergo a direct extrusion process. In direct extrusion operations, a ram pushes against one end of the billet to force the other end through the die. This process continues until the whole billet has been pushed through. Once the extrusions are made, they are cooled and sent for further processing.
- These final steps can include stretching, straightening, work hardening, cutting, heat treating, and surface finishing.