TY - JOUR
T1 - A selective laser melting and solution heat treatment refined Al-12Si alloy with a controllable ultrafine eutectic microstructure and 25% tensile ductility
AU - Li, Xiaopeng
AU - Wang, X.J.
AU - Saunders, Martin
AU - Suvorova, Alexandra
AU - Zhang, L.C.
AU - Liu, Y.J.
AU - Fang, M.H.
AU - Huang, Z.H.
AU - Sercombe, Tim
PY - 2015/8/15
Y1 - 2015/8/15
N2 - © 2015 Published by Elsevier Ltd. on behalf of Acta Materialia Inc. All rights reserved. This study shows that a eutectic Al-12Si alloy with controllable ultrafine microstructure and excellent mechanical properties can be achieved by using selective laser melting and subsequent solution heat treatment. This provides a novel and promising approach to the refinement of eutectic Al-Si alloys. Unlike Al-12Si alloys fabricated and refined by traditional methods, the as-fabricated Al-12Si in this study contains nano-sized spherical Si particles surrounding a supersaturated Al matrix. During solution heat treatment, precipitation and coalescence of the Si particles occur, which decreases the Si concentration in the matrix and sub-micron to micron-sized spherical particles embedded in an Al matrix form. The as-fabricated Al-12Si exhibits significantly better tensile properties than the traditionally produced counterparts; while the solution treated Al-12Si has an extremely high ductility of approximately 25%. Importantly, the mechanical properties of the Al-12Si can be tailored through controlling the precipitation and coalescence of the Si particles by varying the solution heat treatment time. A detailed transmission electron microscopy study was conducted to investigate this Al-12Si alloy with ultrafine eutectic microstructure. The excellent tensile properties have been attributed to the refined eutectic microstructure containing spherical Si particles. The formation of this unique microstructure is due to the super heating and an extremely high cooling rate during selective laser melting and the subsequent solution heat treatment, which enables Si to grow along its most stable plane {1 1 1}Si.
AB - © 2015 Published by Elsevier Ltd. on behalf of Acta Materialia Inc. All rights reserved. This study shows that a eutectic Al-12Si alloy with controllable ultrafine microstructure and excellent mechanical properties can be achieved by using selective laser melting and subsequent solution heat treatment. This provides a novel and promising approach to the refinement of eutectic Al-Si alloys. Unlike Al-12Si alloys fabricated and refined by traditional methods, the as-fabricated Al-12Si in this study contains nano-sized spherical Si particles surrounding a supersaturated Al matrix. During solution heat treatment, precipitation and coalescence of the Si particles occur, which decreases the Si concentration in the matrix and sub-micron to micron-sized spherical particles embedded in an Al matrix form. The as-fabricated Al-12Si exhibits significantly better tensile properties than the traditionally produced counterparts; while the solution treated Al-12Si has an extremely high ductility of approximately 25%. Importantly, the mechanical properties of the Al-12Si can be tailored through controlling the precipitation and coalescence of the Si particles by varying the solution heat treatment time. A detailed transmission electron microscopy study was conducted to investigate this Al-12Si alloy with ultrafine eutectic microstructure. The excellent tensile properties have been attributed to the refined eutectic microstructure containing spherical Si particles. The formation of this unique microstructure is due to the super heating and an extremely high cooling rate during selective laser melting and the subsequent solution heat treatment, which enables Si to grow along its most stable plane {1 1 1}Si.
UR - https://www.scopus.com/pages/publications/84930193425
U2 - 10.1016/j.actamat.2015.05.017
DO - 10.1016/j.actamat.2015.05.017
M3 - Article
SN - 1359-6454
VL - 95
SP - 74
EP - 82
JO - Acta Materialia
JF - Acta Materialia
ER -
