Evaluation of Microstructural Characteristics of High-Si Al Alloy Cylindrical Samples Produced by Rheological Squeeze Casting with Bottom-Up Filling and Flow State Analysis of the Alloy Semi-Solid Slurries

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 23; no. 3; p. 1
• Main Authors: Xiao, Ying, Xi, Shuaiying, Ma, Guodong, Li, Lu, Li, Yongkun, Wang, Qiuping, Xiao, Fan, Zhou, Rongfeng, Jiang, Yehua
• Format: Journal Article
• Language: English
• Published: Sao Carlos Universidade Federal do Sao Carlos, Departamento de Engenharia de Materiais 2020; ABM, ABC, ABPol; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: Aluminum base alloys; Aluminum matrix composites; Bottom casting; Casting alloys; casting defects; Compressing; ENGINEERING, CHEMICAL; Flow characteristics; Fluid dynamics; High-Si Al alloy; Iron; Laminar flow; MATERIALS SCIENCE, MULTIDISCIPLINARY; Metal matrix composites; METALLURGY & METALLURGICAL ENGINEERING; Microstructure; Process parameters; Rheological properties; rheological squeeze casting; Rheology; semi-solid slurry; Semisolids; Silicon; Slurries; Squeeze casting; Turbulent flow; casting defects; microstructure; flow characteristics; rheological squeeze casting; High-Si Al alloy; semi-solid slurry
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/1980-5373-mr-2019-0659

The microstructures of high-Si Al alloy cylindrical simples produced by rheological squeeze-casting with bottom-up filling were investigated. The effect of process parameters on the distribution of hard phases (primary Si and Fe-rich phase) was evaluated, and flow characteristics of semi-solid slurry of high-Si Al alloy were investigated. Differences in volume fractions (VFs) of hard phases between the middle and upper layers of cylindrical samples decreased as the squeezing speed increased. Moreover, the flow state of the semi-solid alloy slurry transitioned from laminar to turbulent flow as the squeezing speed was increased. Movement of gases throughout the semi-solid alloy slurry filling process was analysed under different process parameters. The results provide insights for improving rheological casting of high-Si Al alloy and other Al matrix composites.