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Title: Influence of severe plastic deformation on intermetallic particles in Mg-12 wt.%Zn alloy investigated using transmission electron microscopy

Abstract

The in-depth microstructural characterization of intermetallic particles in an Mg-12 wt.%Zn binary alloy subjected to a severe plastic deformation is presented. The alloy was processed by four passes via equal channel angular pressing with an applied back pressure at a gradually decreasing temperature and analyzed using transmission electron microscopy techniques to observe the influence of processing on intermetallic particles. The results are compared with the initial state of the material prior to severe plastic deformation. The microstructural evolution of the α-Mg matrix and the Mg{sub 21}Zn{sub 25}, Mg{sub 51}Zn{sub 20} and MgZn{sub 2} was analyzed using bright field imaging, selected area electron diffraction, high-resolution transmission electron microscopy and high-angle annular dark field imaging in scanning mode. The plastic deformation process influenced the α-Mg matrix and each type of intermetallic particle. The α-Mg matrix consisted of two types of areas. The first type of area had a highly deformed structure, and the second type of area had a partially recrystallized structure with an average grain size of approximately 250 nm. The Mg{sub 21}Zn{sub 25} microparticles exhibited distinct forms in the α-Mg matrix that were characterized as a single-crystalline form, a nano-crystalline form and a broken up form. No evidence of Mg{submore » 51}Zn{sub 20} nanoparticles within the α-Mg matrix was found in the microstructure, which indicates their dissolution or phase transformation during the deformation process. MgZn{sub 2} nanoparticles exhibited different behavior in both types of α-Mg matrix. Two orientation relationships toward the highly deformed α-Mg matrix were observed; however, there was no relationship toward the partially recrystallized α-Mg matrix. Additionally, the growth of the MgZn{sub 2} nanoparticles was different in the two types of α-Mg matrix. The Mg{sub 51}Zn{sub 20} nanoparticles inside Mg{sub 21}Zn{sub 25} microparticles exhibited a distinct behavior within the single-crystalline or nano-crystalline form of the parent Mg{sub 21}Zn{sub 25} microparticles. The Mg{sub 21}Zn{sub 25} + Mg{sub 51}Zn{sub 20} eutectic compound was confirmed for both forms of the parent Mg{sub 21}Zn{sub 25} microparticles, and the growth of Mg{sub 51}Zn{sub 20} nanoparticles is discussed. - Highlights: •Comprehensive microstructure characterization of Mg-12 wt.%Zn alloy after ECAP-BP •TEM analysis of changes of intermetallic phases caused by SPD •Mg{sub 21}Zn{sub 25} particles exhibit nano-crystalline regions with grain size below 100 nm. •MgZn{sub 2} preserved its orientation relationship toward highly deformed α-Mg after SPD. •Existence of Mg{sub 21}Zn{sub 25} + Mg{sub 51}Zn{sub 20} eutectic remained for each Mg{sub 21}Zn{sub 25} particle form.« less

Authors:
 [1];  [2];  [1];  [1]
  1. Laboratory of Nanostructures and Nanomaterials, Institute of Physics, ASCR, Na Slovance 2, 182 21 Prague 8 (Czech Republic)
  2. (Czech Republic)
Publication Date:
OSTI Identifier:
22689615
Resource Type:
Journal Article
Journal Name:
Materials Characterization
Additional Journal Information:
Journal Volume: 119; Other Information: Copyright (c) 2016 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1044-5803
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BINARY ALLOY SYSTEMS; COMPARATIVE EVALUATIONS; DEFORMATION; ELECTRON DIFFRACTION; EUTECTICS; GRAIN SIZE; INTERMETALLIC COMPOUNDS; MAGNESIUM ALLOYS; MATRICES; MONOCRYSTALS; NANOPARTICLES; NANOSTRUCTURES; PHASE TRANSFORMATIONS; PLASTICITY; PRESSING; TRANSMISSION ELECTRON MICROSCOPY; ZINC ALLOYS

Citation Formats

Němec, M., E-mail: nemecm@fzu.cz, Department of Electrotechnology, Faculty of Electrical Engineering, Czech Technical University, Technická 2, 166 27 Prague 6, Gärtnerová, V., E-mail: gartner@fzu.cz, and Jäger, A., E-mail: jager@fzu.cz. Influence of severe plastic deformation on intermetallic particles in Mg-12 wt.%Zn alloy investigated using transmission electron microscopy. United States: N. p., 2016. Web. doi:10.1016/J.MATCHAR.2016.07.016.
Němec, M., E-mail: nemecm@fzu.cz, Department of Electrotechnology, Faculty of Electrical Engineering, Czech Technical University, Technická 2, 166 27 Prague 6, Gärtnerová, V., E-mail: gartner@fzu.cz, & Jäger, A., E-mail: jager@fzu.cz. Influence of severe plastic deformation on intermetallic particles in Mg-12 wt.%Zn alloy investigated using transmission electron microscopy. United States. doi:10.1016/J.MATCHAR.2016.07.016.
Němec, M., E-mail: nemecm@fzu.cz, Department of Electrotechnology, Faculty of Electrical Engineering, Czech Technical University, Technická 2, 166 27 Prague 6, Gärtnerová, V., E-mail: gartner@fzu.cz, and Jäger, A., E-mail: jager@fzu.cz. Thu . "Influence of severe plastic deformation on intermetallic particles in Mg-12 wt.%Zn alloy investigated using transmission electron microscopy". United States. doi:10.1016/J.MATCHAR.2016.07.016.
@article{osti_22689615,
title = {Influence of severe plastic deformation on intermetallic particles in Mg-12 wt.%Zn alloy investigated using transmission electron microscopy},
author = {Němec, M., E-mail: nemecm@fzu.cz and Department of Electrotechnology, Faculty of Electrical Engineering, Czech Technical University, Technická 2, 166 27 Prague 6 and Gärtnerová, V., E-mail: gartner@fzu.cz and Jäger, A., E-mail: jager@fzu.cz},
abstractNote = {The in-depth microstructural characterization of intermetallic particles in an Mg-12 wt.%Zn binary alloy subjected to a severe plastic deformation is presented. The alloy was processed by four passes via equal channel angular pressing with an applied back pressure at a gradually decreasing temperature and analyzed using transmission electron microscopy techniques to observe the influence of processing on intermetallic particles. The results are compared with the initial state of the material prior to severe plastic deformation. The microstructural evolution of the α-Mg matrix and the Mg{sub 21}Zn{sub 25}, Mg{sub 51}Zn{sub 20} and MgZn{sub 2} was analyzed using bright field imaging, selected area electron diffraction, high-resolution transmission electron microscopy and high-angle annular dark field imaging in scanning mode. The plastic deformation process influenced the α-Mg matrix and each type of intermetallic particle. The α-Mg matrix consisted of two types of areas. The first type of area had a highly deformed structure, and the second type of area had a partially recrystallized structure with an average grain size of approximately 250 nm. The Mg{sub 21}Zn{sub 25} microparticles exhibited distinct forms in the α-Mg matrix that were characterized as a single-crystalline form, a nano-crystalline form and a broken up form. No evidence of Mg{sub 51}Zn{sub 20} nanoparticles within the α-Mg matrix was found in the microstructure, which indicates their dissolution or phase transformation during the deformation process. MgZn{sub 2} nanoparticles exhibited different behavior in both types of α-Mg matrix. Two orientation relationships toward the highly deformed α-Mg matrix were observed; however, there was no relationship toward the partially recrystallized α-Mg matrix. Additionally, the growth of the MgZn{sub 2} nanoparticles was different in the two types of α-Mg matrix. The Mg{sub 51}Zn{sub 20} nanoparticles inside Mg{sub 21}Zn{sub 25} microparticles exhibited a distinct behavior within the single-crystalline or nano-crystalline form of the parent Mg{sub 21}Zn{sub 25} microparticles. The Mg{sub 21}Zn{sub 25} + Mg{sub 51}Zn{sub 20} eutectic compound was confirmed for both forms of the parent Mg{sub 21}Zn{sub 25} microparticles, and the growth of Mg{sub 51}Zn{sub 20} nanoparticles is discussed. - Highlights: •Comprehensive microstructure characterization of Mg-12 wt.%Zn alloy after ECAP-BP •TEM analysis of changes of intermetallic phases caused by SPD •Mg{sub 21}Zn{sub 25} particles exhibit nano-crystalline regions with grain size below 100 nm. •MgZn{sub 2} preserved its orientation relationship toward highly deformed α-Mg after SPD. •Existence of Mg{sub 21}Zn{sub 25} + Mg{sub 51}Zn{sub 20} eutectic remained for each Mg{sub 21}Zn{sub 25} particle form.},
doi = {10.1016/J.MATCHAR.2016.07.016},
journal = {Materials Characterization},
issn = {1044-5803},
number = ,
volume = 119,
place = {United States},
year = {2016},
month = {9}
}