Shear assisted processing and extrusion of enhanced strength aluminum

Shear Assisted Processing and Extrusion (ShAPE) enables the extrusion of many alloys with enhanced properties. In this study, ShAPE was used to extrude tubes of aluminum alloy 6063 measuring 12 mm in diameter at extrusion speeds up to 3.8 m/min, an increase of 10 times over what has previously been reported for ShAPE. Increasing the extrusion speed from 0.7 to 3.8 m/min resulted in using 68% less process energy at steady state without any loss in mechanical properties. As-extruded tubes had ultimate tensile strengths on par with conventional T5 extrusions and double the elongation at break. ShAPE extruded tubes that underwent a T5 heat treatment had yield and ultimate strengths of 198 and 234 MPa, respectively, which is similar to 30% higher than standard T5 material and comparable to T6 properties. Microstructural analyses were performed on as-extruded and T5 treated tubes. Grain refinement below 20 mu m was identified, with no detectable growth of macroscale Mg2Si strengthening precipitates. Nanoscale beta '' was not observed in the as-extruded materials but was prominent after T5 heat treatment suggesting that beta '' strengthening precipitates were solutionized in situ during the ShAPE process. The ability to perform solution heat treating in situ, rather than post-extrusion, eliminates an energy intensive process step and is applicable to a wide variety of alloys.

Automated summary

The Shear Assisted Processing and Extrusion (ShAPE) technology was successfully applied to extrude tubes of aluminum alloy 6063, achieving the goals of increased extrusion speed, reduced energy consumption, and improved properties. Through T5 heat treatment of the extruded tubes, the ultimate tensile strength and elongation at break were significantly improved, with potential wide applications for a range of alloys.