Transgranular liquation cracking of grains in the semi-solid state.pdf (2.31 MB)
Download file

Transgranular liquation cracking of grains in the semi-solid state

Download (2.31 MB)
journal contribution
posted on 22.02.2019, 10:57 by S Karagadde, PD Lee, B Cai, JL Fife, MA Azeem, KM Kareh, C Puncreobutr, D Tsivoulas, T Connolley, RC Atwood
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.

Funding

This work was made possible by the facilities and support provided by the Manchester X-ray Imaging Facility and Research Complex at Harwell, funded in part by the EPSRC (EP/I02249X/1) and EU (RFSR-PR-10005 DDT).

History

Citation

Nat Commun, 2015, 6, pp. 8300-?

Author affiliation

/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Engineering

Version

VoR (Version of Record)

Published in

Nat Commun

eissn

2041-1723

Acceptance date

07/08/2015

Copyright date

2015

Available date

22/02/2019

Publisher version

https://www.nature.com/articles/ncomms9300

Language

en

Usage metrics

Categories

Keywords

Licence

Exports