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Ca-modified Al–Mg–Sc alloy with high strength at elevated temperatures due to a hierarchical microstructure.

Authors :
Du, Haiquan
Zhang, Shasha
Zhang, Bingyi
Tao, Xuewei
Yao, Zhengjun
Belov, Nikolay
van der Zwaag, Sybrand
Liu, Zili
Source :
Journal of Materials Science; Oct2021, Vol. 56 Issue 28, p16145-16157, 13p, 3 Color Photographs, 1 Black and White Photograph, 3 Diagrams, 3 Charts, 3 Graphs
Publication Year :
2021

Abstract

Al-Mg alloys are normally prone to lose part of their yield and tensile strength at high temperatures due to insufficient thermal stability of the microstructure. Here, we present a Ca-modified Al–Mg–Sc alloy demonstrating high strength at elevated temperatures. The microstructure contains Al<subscript>4</subscript>Ca phases distributed as a network along the grain boundary and Al<subscript>3</subscript>(Sc,Zr) nano-particles dispersed within the grains. The microstructure evolution and age-hardening analysis indicate that the combination of an Al<subscript>4</subscript>Ca network and Sc-rich nano-particles leads to excellent thermal stability even upon aging at 300 °C. The tensile strength of the alloy for temperatures up to 250 °C is significantly improved by an aging treatment and is comparable with the commercial heat-resistant aluminum alloys, i.e., A356 and A319. At a high temperature of 300 °C, the tensile strength is superior to the above-mentioned commercial alloys, even more so when expressed as the specific strength due to the low density of Ca-modified Al–Mg–Sc alloy. The excellent high-temperature strength results from a synergistic effect of solid solution strengthening, grain boundary strengthening and nanoparticle order strengthening. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00222461
Volume :
56
Issue :
28
Database :
Complementary Index
Journal :
Journal of Materials Science
Publication Type :
Academic Journal
Accession number :
151628886
Full Text :
https://doi.org/10.1007/s10853-021-06310-5