Effects of Grain Morphology on Flow Behavior of Semi-Solid Slurries

Abstract:

The flow behavior of semi-solid slurry determines the quality of the castings produced by the semi-solid forming process. Many studies have done to investigate the flow behavior of slurry under different conditions, and results show that the rheological behavior of slurry with dendritic structure is inappropriate for semi-solid forming. In this study, slurries with varying morphologies of grain for the same alloy with the same fraction solid have tested using a partial filling method. The SEED process was employed, and the pouring temperature adjusted to prepare semi-solid slurries with different grain morphologies. The flow pattern, entrapped air during the filling process, and also microstructure of the samples were examined to characterize the macro and micro flow behavior. The results show that a turbulent macro-flow, leading to entrapped air, and severe segregation appeared in the sample using slurry of T_pour ≥ 660 °C . For the slurry of T_pour < 660 °C, none of the three phenomena found in the sample. This investigation further showed that the detriment of dendrite on the semi-solid forming process, and implied that large size dendrite in semi-solid slurry must avoided.

• Periodical: Solid State Phenomena (Volume 327)
• Pages: 140-145
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.327.140
• Online since: January 2022
• Authors: Min Luo, Da Quan Li, Hong Xing Lu, Wen Ying Qu, Hong Zhang, Le Cheng, Qiang Zhu*
• Keywords: Dendrites, Flow Behavior, Microstructure, Segregation, Semi-Solid Diecasting

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