Resources / Solutions / Strength vs. Weight vs. Cost
As you look at an aluminum extruded part from a cost standpoint, the alloy 6063 extruded in a solid shape is going to be the most cost effective way to approach an aluminum extruded part. A variation of 6063, 6060 with somewhat lower mechanical properties does allow for more intricate extrusion profiles with slightly better heat transfer, making it a possible alternative for heat sink profiles. However, it doesn’t always give you the best performance in regard to weight vs. strength. This factor often drives the application to a different alloy. Certainly with the 6000 series alloys there are a number of options available to increase the mechanical properties over 6063. However, every step we take up the ladder of mechanical properties causes us to lose some extrudability of the alloy. In addition to and parallel with that, it also has a negative affect on the extruded finish, which can have an impact on the aesthetic nature of the product. Two common options to increase properties within the 6000 series alloy would be 6005 or 6061. The mechanical properties of each alloy in their highest temper designation available are listed below. You will see a significant increase in the mechanical properties. Also, attached you will see the extrudability table (Exhibit 1) which has an inverse curve to mechanical properties which basically reduces the speed at which the product can be extruded and has a negative impact on the cost. As we move up the mechanical properties, it also has somewhat of a bearing on our ability to produce a thin wall lighter weight extrusion. With the 6063 alloy, we would be able to go down to a wall thickness of .025” thickness and with 6061 we would be at a minimum of .035”-.040”*. The alloy also has an impact on the complexity of the shape to be extruded. When lightweight and high strength are the goals, we should keep in mind the profile design of the extrusion itself. Following are some examples of extruded shapes where center webs have been added as a load point of the extrusion or the extrusion is designed to have a profile shape to take on the higher stress of that certain area (Exhibit 2). Working with our customers, we have had lots of opportunities to work through these issues of weight vs. strength. We would be happy to share our ideas with you. In addition to that, we have also worked with some of our customers to develop special alloys that can give increased properties beyond the 6061. We are able to see properties in excess of 30% greater than 6061 T6, however there are some significant drawbacks to this from a standpoint of minimum volumes required. We are always available to our customers to help them through these issues with one-on-one design help. We also have available a 2-3 hour non-commercial aluminum extrusion seminar that can be presented at your location or at our facility. The seminar will explain these aspects in much greater detail and can be designed to address your specific issues. *Depending on profile characteristics and extrusion press size. Aluminum Alloys 6000 Series:
6063
6060
6463
6061
6005(A)
Temper Designations
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