In-situ differential fast scanning calorimetry of rapid solidification of aluminium-based alloys
Final Report Abstract
Tailoring microstructures and properties in metal alloys, particularly in additive manufacturing (AM) applications, necessitates a comprehensive understanding of their rapid solidification behavior. However, investigating rapid solidification processes in situ poses challenges due to the lack of precise measurements of cooling rates, nucleation undercooling, and solidification time. This study employed differential fast scanning calorimetry (DFSC) to explore the rapid solidification of micro-sized Al-Si alloy particles, encompassing compositions including Al-Si1, Al-Si10, Al-Si12, Al-Si20 (mass%), and AlSi10Mg, with controllable cooling rates ranging from 100 K/s to 1,000,000 K/s. By analyzing nucleation undercooling and microstructure, the solidification sequence and various mechanisms of α-Al phase formation were proposed. A modified model using classical nucleation theory (CNT), incorporating surface heterogeneous nucleation and interface/bulk heterogeneous nucleation for α-Al, was employed. Additionally, the isothermal DFSC method was utilized to investigate the rapid solidification of these alloys. Both dendrite arm spacing and eutectic spacing decrease with increasing cooling rate, as well as decreasing solidification temperature. The continuous cooling treatment yields finer microstructures compared to those observed in the isothermal treatment within a similar solidification temperature range. The combination of in-situ DFSC and microstructure characterization allows for the observation of rapidly solidified structures of individual metallic particles through controlled rapid cooling and known nucleation undercooling. The results indicate that to represent microstructures in AM components accurately, it is necessary to utilize large nucleation undercoolings (above approximately 100 K) and high DFSC cooling rates (above approximately 10,000 K/s). Therefore, this approach is effective in investigating the effects of cooling rate and undercooling on microstructure evolution under rapid solidification conditions, particularly in AM processes.
Publications
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Metallographic Preparation of Single Powder Particles. Practical Metallography, 58(3), 129-139.
Milkereit, B.; Meißner, Y.; Ladewig, C.; Osten, J.; Peng, Q.; Yang, B.; Springer, A. & Keßler, O.
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Nucleation Behavior of a Single Al-20Si Particle Rapidly Solidified in a Fast Scanning Calorimeter. Materials, 14(11), 2920.
Peng, Qin; Yang, Bin; Milkereit, Benjamin; Liu, Dongmei; Springer, Armin; Rettenmayr, Markus; Schick, Christoph & Keßler, Olaf
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Nucleation behaviour and microstructure of single Al-Si12 powder particles rapidly solidified in a fast scanning calorimeter. Journal of Materials Science, 56(22), 12881-12897.
Yang, Bin; Peng, Qin; Milkereit, Benjamin; Springer, Armin; Liu, Dongmei; Rettenmayr, Markus; Schick, Christoph & Keßler, Olaf
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Rapid solidification of Al-Si alloys using differential fast scanning calorimetry. Journal of Alloys and Compounds, 965, 171346.
Peng, Qin; Zhang, Yunhu; Wenner, Sigurd; Yang, Bin; Milkereit, Benjamin; Broer, Jette; Springer, Armin; Schick, Christoph & Keßler, Olaf
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Continuous cooling and isothermal solidification analysis of AlSi10Mg using differential fast scanning calorimetry. Thermochimica Acta, 733, 179674.
Peng, Qin; Zhang, Yunhu; Yang, Bin; Broer, Jette; Springer, Armin; Schick, Christoph & Keßler, Olaf
