TY - JOUR

T1 - Effect of solidification rate on pore connectivity of aluminium foams and its consequences on mechanical properties

AU - Lázaro, J.

AU - Solórzano, E.

AU - Rodríguez-Perez, M.A.

AU - Kennedy, Andrew R.

N1 - This is the author’s version of a work that was accepted for publication in Materials Science and Engineering: A. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Materials Science and Engineering: A, 672, 2017 DOI: 10.1016/j.msea.2016.07.015

PY - 2016/8/30

Y1 - 2016/8/30

N2 - This study evaluates the influence of solidification rate on the generation and control of pore connectivity of closed-cell aluminium foams. Additionally, it gives the experimental support to evaluate and model the effect of this pore connectivity on the mechanical properties. A collection of AlSi10 foams produced via powder metallurgy route, with porosities between 0.65 and 0.85, were examined. During production, applied heating conditions were the same in all cases but the cooling conditions were varied in order to promote different solidification rates in a wide range (from -1 to -15 K/s). Structural characterisation was performed by gas pycnometry and X- ray microtomography while the mechanical properties were evaluated by microhardness measurements and uniaxial compression tests. Results showed a clear reduction of pore connectivity when increasing the solidification rate. The consequence is a prominent improvement of the foam strength over the one expected from just the matrix refinement. Further analysis on this relationship between the pore connectivity and the mechanical properties, has allowed to propose a correction to the theoretical model for collapse strength in closed cell foams to consider such contribution and predict more accurate results.

AB - This study evaluates the influence of solidification rate on the generation and control of pore connectivity of closed-cell aluminium foams. Additionally, it gives the experimental support to evaluate and model the effect of this pore connectivity on the mechanical properties. A collection of AlSi10 foams produced via powder metallurgy route, with porosities between 0.65 and 0.85, were examined. During production, applied heating conditions were the same in all cases but the cooling conditions were varied in order to promote different solidification rates in a wide range (from -1 to -15 K/s). Structural characterisation was performed by gas pycnometry and X- ray microtomography while the mechanical properties were evaluated by microhardness measurements and uniaxial compression tests. Results showed a clear reduction of pore connectivity when increasing the solidification rate. The consequence is a prominent improvement of the foam strength over the one expected from just the matrix refinement. Further analysis on this relationship between the pore connectivity and the mechanical properties, has allowed to propose a correction to the theoretical model for collapse strength in closed cell foams to consider such contribution and predict more accurate results.

KW - Aluminium foam

KW - Solidification

KW - Pore connectivity

KW - Mechanical properties

KW - Modelling

U2 - 10.1016/j.msea.2016.07.015

DO - 10.1016/j.msea.2016.07.015

M3 - Journal article

VL - 672

SP - 236

EP - 246

JO - Materials Science and Engineering: A

JF - Materials Science and Engineering: A

SN - 0921-5093

ER -