High-temperature deformation of supersaturated Al-Sc-Zr produced via melt-spinning and extrusion

Document Type

Article

Publication Date

11-1-2022

Department

Department of Materials Science and Engineering

Abstract

Sc and Zr additions in Al matrix offer enormous potential for strengthening at elevated temperatures due to formation of coarsening resistant precipitates. The high-temperature properties of supersaturated Al-0.4Sc-0.4Zr at% alloy, produced via melt-spinning and extrusion, were studied in creep and elevated temperature compression. Given the larger amount of solute resulting from rapid solidification, the elevated temperature compressive strength of the supersaturated Al-0.4Sc-0.4Zr at% was significantly higher compared to dilute Al-0.06Sc-0.06Zr at%. The operating deformation mechanism at elevated temperatures in both alloys was dislocation climb, and the difference in threshold stress was assessed between Al-0.4Sc-0.4Zr at% and Al-0.06Sc-0.06Zr at%. The larger threshold stress in the supersaturated Al-0.4Sc-0.4Zr at% was attributed to the different microstructure due to the processing. The stress exponents and activation energies from the creep tests are consistent with the diffusion-controlled dislocation climb mechanism. The small grain size led to diffusional creep in the low stress regime in both alloys.

Publication Title

Materials Science and Engineering A

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