Beschreibung
The desire for high recyclability has led to the development of so-called crossover alloys. The concept of this approach is the use of one single alloy combining the required properties of conventional systems, instead of employing various alloy systems. Al-Mg-Zn-Cu alloys with a low Zn/Mg ratio obtain a high strength through age hardening via the precipitation of the T Mg32(Al,Zn,Cu)49 phase and its precursors. Due to their high resistance against hot cracking, Al-Mg-Zn-Cu alloys with a low Zn/Mg ratio have recently also been considered for additive manufacturing. For age-hardening alloys knowledge of the quench rate sensitivity is crucial, since the maximum hardness through aging can only be achieved if no precipitation occurs during cooling after the solution heat treatment. Conventional alloys have been well investigated in this regard, but little is yet known about the quench rate sensitivity of Al-Mg-Zn-Cu alloys. For that reason, the quench rate sensitivity of an Al-Mg-Zn-Cu alloy developed at the Austrian Institute of Technology was studied with in situ small-angle X-ray scattering (SAXS) and high-energy X-ray diffraction (HEXRD) at a synchrotron X-ray source. Solution heat treatments were performed using a dilatometer. Five different cooling rates were applied to investigate the precipitation behavior during cooling. Each specimen was subsequently continuously annealed in order to examine the influence of the cooling rate on an aging heat treatment. Additionally, the same set of experiments was performed on a conventional AA7075 alloy, which served as a reference. The results demonstrate that the critical cooling rate, for which no precipitation occurs, is in the order of 1 K/s for the Al-Mg-Zn-Cu alloy and 100 K/s for the AA7075 alloy. In conclusion, the Al-Mg-Zn-Cu alloy exhibits a very low quench rate sensitivity, suggesting a robust behavior during advanced processing techniques such as additive manufacturing.| Zeitraum | 4 Sept. 2022 → 8 Sept. 2022 |
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| Ereignistitel | 18th International Conference on Aluminium Alloys |
| Veranstaltungstyp | Sonstiges |
| Bekanntheitsgrad | International |
Research Field
- Wire-Based Additive Manufacturing