A Quantitative Study on the Interaction Between Silicon Content and Heat Treatment on Thermal Conductivity of Al-Si Binary Alloys

作者：Luo, Gan^*; Zhou, Xiong; Li, Chengbo; Du, Jun; Huang, Zhenghua

来源：International Journal of Metalcasting, 2022, 16(3): 1585-1594.

DOI：10.1007/s40962-021-00706-4

• Al-Si binary alloys
• thermal conductivity
• heat treatment
• Si concentration
• structural models

In this study, the room temperature thermal conductivities and microstructures of Al-Si binary alloys in as-cast, low-temperature annealing state and solid solution state are investigated. The experimental results show that annealing treatment increases the thermal conductivities of these alloys because of the decreasing Si concentration in alpha-Al matrix, which is determined by EPMA. The effect of solution treatment on the thermal conductivity of Al-xSi (0 <= x <= 12) alloys can be divided into two stages. When the Si content is less than 3 wt%, the thermal conductivities of solution treated specimens are lower than that of as-cast, which is mainly attributed to the increase in Si concentration. However, solution treatment improves the thermal conductivities of Al-xSi (x > 3) alloys owing to the spheroidization of Si phase. Quantitative study is conducted on the effect of Si element on thermal conductivity of as-cast Al-xSi alloys. The thermal conductivities of Al-xSi alloys are fitted using modified Series and Maxwell models based on the Si concentration in alpha-Al matrix, distribution and volume fractions of Si phases. The modified structural models provide a better fit to the measured thermal conductivity data.