Natural and artificial aging in Mg-Gd binary alloys
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10390004" target="_blank" >RIV/00216208:11320/18:10390004 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1016/j.jallcom.2017.12.026" target="_blank" >https://doi.org/10.1016/j.jallcom.2017.12.026</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.jallcom.2017.12.026" target="_blank" >10.1016/j.jallcom.2017.12.026</a>
Alternative languages
Result language
angličtina
Original language name
Natural and artificial aging in Mg-Gd binary alloys
Original language description
Early precipitation stages are now frequently observed in Mg alloys with rare earth due to a development of new microscopy techniques. Information about a very early precipitation at room temperature (i.e. natural aging, NA), however, is rare even in Mg alloys with a very well described precipitation sequence. Moreover, there are only few works dealing with an influence of NA on subsequent thermal processes in Mg alloys. The aim of this work was to study kinetics of the NA performed up to 5 years in an Mg-RE system and its influence on a subsequent artificial aging. The solution treated Mg-Gd was chosen as a model binary system where the NA as well as precipitation development during isochronal and isothermal heat treatment was observed. Electrical resistivity measurements at low and well-defined temperature (77 K) and Vickers microhardness were used for monitoring of a solute clustering during the NA. The kinetics of this process is much slower than observed in aluminum alloys and both methods give identical values of kinetics parameters in simple models. The validity of concentration dependences of microhardness and yield stress values supports these models. The NA intensifies precipitation strengthening in solution treated Mg-Gd alloy with 15 wt % Gd isochronally annealed up to 200 degrees C. Formation of short range ordered super hexagons consisting of 6 columns of Gd atoms along the [ 0001] direction resembling the D0(19) structure was revealed by electron diffraction in specimen isochronally annealed up to 200 degrees C. The maximum hardening during isochronal annealing up to 300 degrees C shifts to higher annealing temperatures in the naturally aged specimen. Precipitates of the orthorhombic beta' phase (a(beta') = 2aMg, b(beta') = 4 root 3a(Mg), c(beta') = c(Mg)) were identified after isothermal artificial aging for 165 h at 200 degrees C in the Mg-Gd with 15 wt% in a cell-like arrangement despite of the NA. Since the mesh size is much smaller in the naturally aged alloy, however, it causes the better hardening effect. (C) 2017 Elsevier B.V. All rights reserved.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10302 - Condensed matter physics (including formerly solid state physics, supercond.)
Result continuities
Project
<a href="/en/project/GA16-12828S" target="_blank" >GA16-12828S: Defect-assisted early precipitation stages in lightweight hardenable alloys</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Alloys and Compounds
ISSN
0925-8388
e-ISSN
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Volume of the periodical
738
Issue of the periodical within the volume
MAR 25
Country of publishing house
CH - SWITZERLAND
Number of pages
9
Pages from-to
173-181
UT code for WoS article
000419214800022
EID of the result in the Scopus database
2-s2.0-85038882248