Microstructure development of ultra fine grained Mg-22 wt%Gd alloy prepared by high pressure torsion

被引：17

作者：

Cizek, J. ^{[1
]}

Hruska, P. ^{[1
]}

Vlasak, T. ^{[1
]}

Vlcek, M. ^{[1
,2
]}

Janecek, M. ^{[2
]}

Minarik, P. ^{[2
]}

Krajnak, T. ^{[2
]}

Slapakova, M. ^{[2
]}

Dopita, M. ^{[3
]}

Kuzel, R. ^{[3
]}

Kmjec, T. ^{[1
]}

Kim, J. G. ^{[4
]}

Kim, H. -S. ^{[4
]}

机构：

[1] Charles Univ Prague, Fac Math & Phys, Dept Low Temp Phys, V Holesovickach 2, CZ-18000 Prague 8, Czech Republic

[2] Charles Univ Prague, Fac Math & Phys, Dept Phys Mat, Ke Karlovu 5, CZ-12116 Prague 2, Czech Republic

[3] Charles Univ Prague, Fac Math & Phys, Dept Condensed Matter Phys, Ke Karlovu 5, CZ-12116 Prague 2, Czech Republic

[4] POSTECH, Dept Mat Sci & Engn, Pohang 790784, South Korea

来源：

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING | 2017年 / 704卷

基金：

新加坡国家研究基金会;

关键词：

Mg alloy; Ultra fine grained material; High pressure torsion; Positron annihilation; Y-ZR ALLOY; LINE-PROFILE ANALYSIS; HALL-PETCH BREAKDOWN; MECHANICAL-PROPERTIES; THERMAL-STABILITY; POSITRON-LIFETIME; UNEXPECTED FORMATION; MAGNESIUM ALLOY; RARE-EARTH; DEFORMATION;

D O I：

10.1016/j.msea.2017.07.100

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

A hardenable lightweight Mg-22 wt%Gd alloy with ultra fine grained (UFG) structure was prepared by high pressure torsion (HPT) at ambient temperature. The development of microstructure during HPT processing was investigated. A homogeneous UFG structure with grain size of 300 nm was achieved after 15 HPT revolutions. The UFG alloy exhibits enhanced strength due to work strengthening by tangled dislocations forming a dense forest throughout grains. Dislocation density in the sample was determined by positron annihilation spectroscopy (PAS) and X-ray line profile analysis (XLPA). It was found that there is an additional source of X-ray profile broadening in addition to small crystallites and micro-strains caused by dislocations. The additional micro-strain component was attributed to lattice modulation by Gd-rich nano-wires formed by agglomeration of Gd solutes and to strains arising from boundaries of crystallite domains and inter-domain interactions. Analysis of the influence of the crystallite size on the strength of UFG Mg-22 wt%Gd alloy revealed a breakdown in the HallPetch relationship when the crystallite size decreased below a critical value of approximate to 30 nm.

引用

页码：181 / 191

页数：11

共 91 条

[21] High-pressure torsion of hafniurn [J].