Microstructure and mechanical properties of bulk nanostructured Cu–Ta alloys consolidated by equal channel angular extrusion

Nanostructured Cu–Ta alloys have shown promise as high-strength nanocrystalline materials in part due to their limited grain growth at high temperatures. In the present study, Cu–Ta alloy powders, synthesized via high-energy cryogenic mechanical alloying, were consolidated into bulk nanostructured s...

Full description

Saved in:
Bibliographic Details
Published in:Acta materialia 2014-09, Vol.76, p.168-185
Main Authors: Darling, K.A., Tschopp, M.A., Guduru, R.K., Yin, W.H., Wei, Q., Kecskes, L.J.
Format: Article
Language:English
Subjects:
Alloys
Applied sciences
Consolidation
Copper
COPPER ALLOYS (40 TO 99.3 CU)
Copper base alloys
Cu–Ta alloys
DISLOCATIONS
Dynamic compression test
Equal channel angular extrusion
Equal channel angular pressing
Exact sciences and technology
EXTRUSION
HARDNESS
Mechanical behavior
MECHANICAL PROPERTIES
Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology
Metals. Metallurgy
MICROSTRUCTURES
Nanocrystalline alloys
Nanocrystals
Nanostructure
Strain hardening
STRAIN HARDENING MECHANISMS
STRESS RELAXATION
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Nanostructured Cu–Ta alloys have shown promise as high-strength nanocrystalline materials in part due to their limited grain growth at high temperatures. In the present study, Cu–Ta alloy powders, synthesized via high-energy cryogenic mechanical alloying, were consolidated into bulk nanostructured specimens using equal channel angular extrusion (ECAE) at high temperatures. Subsequent microstructure characterization indicated full consolidation, which resulted in an equiaxed grain structure for the Cu matrix along with the formation of fine Ta precipitates, the size distributions of which varied both with composition and processing temperature. Microhardness, compression and shear punch testing indicated, in some cases, an almost threefold increase in mechanical properties above that predicted by Hall–Petch estimates for pure nanocrystalline Cu. Stress relaxation tests substantiated the strain-hardening behavior and grain-size-dependent dislocation activity observed in the nanocrystalline Cu–Ta samples.
ISSN:1359-6454
1873-2453
DOI:10.1016/j.actamat.2014.04.074