Effects of Nb and Ta additions on the strength and coarsening resistance of precipitation-strengthened Al-Zr-Sc-Er-Si alloys

Authors

Dinc Erdeniz, Marquette UniversityFollow
Anthony De Luca, Northwestern University
David N. Seidman, Northwestern University
David C. Dunand, Northwestern University

Document Type

Article

Language

eng

Publication Date

7-2018

Publisher

Elsevier

Source Publication

Materials Characterization

Source ISSN

1044-5803

Abstract

A dilute Al-0.07Zr-0.02Sc-0.005Er-0.06Si (at.%) alloy was microalloyed with 0.08 at.% Nb or Ta. Atom-probe tomography reveals that, upon aging, Nb and Ta partition to the coherent L1₂-Al₃(Zr,Sc,Er) nanoprecipitates (with average concentrations of 0.2 and 0.08 at.%, respectively), with both segregating at the matrix/nanoprecipitate heterophase interface. This is consistent with the Nb- and Ta-modified alloys exhibiting, as compared to the unmodified alloy: (i) higher peak microhardness, from a higher nanoprecipitate volume fraction and/or latticeparameter mismatch; and (ii) improved aging resistance, from slower nanoprecipitate coarsening due to the small diffusivities of niobium and tantalum in aluminum. Analogous results were previously reported for a V-modified alloy.

Comments

Accepted version. Materials Characterization, Vol. 141 (July 2018): 260-266. DOI. © 2018 Elsevier. Used with permission.

Dinc Erdeniz was affiliated with Northwestern University at the time of publicaiton.

Recommended Citation

Erdeniz, Dinc; De Luca, Anthony; Seidman, David N.; and Dunand, David C., "Effects of Nb and Ta additions on the strength and coarsening resistance of precipitation-strengthened Al-Zr-Sc-Er-Si alloys" (2018). Mechanical Engineering Faculty Research and Publications. 234.
https://epublications.marquette.edu/mechengin_fac/234