TY - JOUR

T1 - Effects of Si and Sr elements on solidification microstructure and thermal conductivity of Al–Si-based alloys

AU - Zhang, Xun

AU - Zhou, Yuli

AU - Zhong, Gu

AU - Zhang, Junchao

AU - Chen, Yunan

AU - Jie, Wanqi

AU - Schumacher, Peter

AU - LI, Jiehua

N1 - Publisher Copyright: © 2022, The Author(s).

PY - 2022/3/8

Y1 - 2022/3/8

N2 - Effects of Si and Sr on solidification microstructure and thermal conductivity of Al–Si binary alloys and Al–9Si–Sr ternary were investigated, respectively, with a special focus on the relationship between solidification microstructure and thermal conductivity. It was found that (i) in Al–Si binary alloys, with increasing Si content, α-Al grain size increases and then decreases when Si content is over 7 wt%, while the percentage of eutectic Si continuously increases, which significantly decreases the thermal conductivity and electrical conductivity, and (ii) in Al–9Si–Sr ternary alloys, the presence of Sr has no significant effect on α-Al grain, but effectively modifies eutectic Si and significantly improves the thermal and electrical conductivity. On this basis, two theoretical calculation models [the Maxwell model and the Hashin–Shtrikman (H–S) model] were used to elucidate the relationship between solidification microstructure and thermal conductivity. Compared with the Maxwell model, the H–S model fits better with the measured values. The obtained results are very helpful to the precise composition control during alloy design and recycling of Al–Si-based alloys with the aim to further improve the thermal conductivity of Al–Si-based alloys. Graphical abstract: [Figure not available: see fulltext.]

AB - Effects of Si and Sr on solidification microstructure and thermal conductivity of Al–Si binary alloys and Al–9Si–Sr ternary were investigated, respectively, with a special focus on the relationship between solidification microstructure and thermal conductivity. It was found that (i) in Al–Si binary alloys, with increasing Si content, α-Al grain size increases and then decreases when Si content is over 7 wt%, while the percentage of eutectic Si continuously increases, which significantly decreases the thermal conductivity and electrical conductivity, and (ii) in Al–9Si–Sr ternary alloys, the presence of Sr has no significant effect on α-Al grain, but effectively modifies eutectic Si and significantly improves the thermal and electrical conductivity. On this basis, two theoretical calculation models [the Maxwell model and the Hashin–Shtrikman (H–S) model] were used to elucidate the relationship between solidification microstructure and thermal conductivity. Compared with the Maxwell model, the H–S model fits better with the measured values. The obtained results are very helpful to the precise composition control during alloy design and recycling of Al–Si-based alloys with the aim to further improve the thermal conductivity of Al–Si-based alloys. Graphical abstract: [Figure not available: see fulltext.]

UR - http://www.scopus.com/inward/record.url?scp=85125886884&partnerID=8YFLogxK

U2 - 10.1007/s10853-022-07045-7

DO - 10.1007/s10853-022-07045-7

M3 - Article

VL - 57.2022

SP - 6428

EP - 6444

JO - Journal of materials science

JF - Journal of materials science

SN - 0022-2461

IS - March

ER -