Transgranular liquation cracking of grains in the semi-solid state
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Author(s)
Type
Journal Article
Abstract
Grain refinement via semi-solid deformation is desired to obtain superior mechanical properties of cast components. Using quantitative in situ synchrotron X-ray tomographic microscopy, we show an additional mechanism for the reduction of grain size, via liquation assisted transgranular cracking of semi-solid globular microstructures. Here we perform localized indentation of Al-15wt.%Cu globular microstructures, with an average grain size of ~480 μm, at 555 °C (74% solid fraction). Although transgranular fracture has been observed in brittle materials, our results show transgranular fracture can also occur in metallic alloys in semi-solid state. This transgranular liquation cracking (TLC) occurs at very low contact stresses (between 1.1 and 38 MPa). With increasing strain, TLC continues to refine the size of the microstructure until the grain distribution reaches log-normal packing. The results demonstrate that this refinement, previously attributed to fragmentation of secondary arms by melt-shearing, is also controlled by an additional TLC mechanism.
Date Issued
2015-09-10
Date Acceptance
2015-08-07
Citation
Nature Communications, 2015, 6
ISSN
2041-1723
Publisher
Nature Publishing Group
Journal / Book Title
Nature Communications
Volume
6
Copyright Statement
This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
License URL
Sponsor
Engineering & Physical Science Research Council (E
Grant Number
EP/I021566/1
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
SYNCHROTRON TOMOGRAPHIC QUANTIFICATION
X-RAY TOMOGRAPHY
AL-CU ALLOY
IN-SITU
ALUMINUM-ALLOYS
STRESS-CORROSION
DEFORMATION
BEHAVIOR
FRACTURE
TEMPERATURE
MD Multidisciplinary
Publication Status
Published
Article Number
8300