SUPERPLASTIC MICROSTRUCTURE OF MODIFIED AA-5083 ALUMINUM ALLOY PROCESSED BY EQUAL CHANNEL ANGULAR EXTRUSION
The Equal Channel Angular Extrusion (ECAE) process offers several potential advantages in the processing of SPF-grade aluminum alloys. The ability of the ECAE process to achieve high levels of work through localized shearing can develop a well defined subgrain structure and provide a mechanism for distributing the eutectic constituent particles and dispersoids that play a critical role in the recrystallization process and resulting thermally stable fine-grain size. In addition, with ECAE there is the unique ability to achieve these desirable microstructures in bulk form, without reducing the dimensions of the starting material, as is the case in conventional processing of SPF materials. The objective of this work was to process, via ECAE, a 5000-series aluminum alloy in bulk-form to produce a fine-grain (~1 mm), thermally stable SPF microstructure. Previous work performed at Pacific Northwest National Laboratory on modified 5000-series alloys identified several compositional features that assist in developing a fine, thermally stable microstructure required for SPF. These modifications, which include an increase in Mn level and the addition of Zr, develop fine dispersoids that assist in grain refinement and control excessive grain growth at SPF temperatures. This research work was sponsored by the Office of Heavy Vehicle Technologies within the Department of Energy-Office of Transportation Technologies.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 950195
- Report Number(s):
- PNNL-SA-32379; VT0502020; TRN: US200910%%24
- Resource Relation:
- Conference: Ultrafine Grained Materials: Proceedings of a Symposium held during the 2000 TMS Annual Meeting, 411-420
- Country of Publication:
- United States
- Language:
- English
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