Grain refinement of primary silicon in hypereutectic Al-Si alloys by different P-containing compounds

• Published in: China foundry Vol. 18; no. 1; pp. 37 - 44
• Main Authors: Njuguna, Benson Kihono, Li, Jia-yan, Tan, Yi, Sun, Qian-qian, Li, Peng-ting
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 2021; Foundry Journal Agency; State Key Laboratory of Advanced Special Steel,Shanghai University,Shanghai 200444,China; School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China%Shandong Shanda Al&Mg Melt Technology Company Limited,Jinan 250061,China%School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China
• Subjects: Alloys; Aluminum compounds; Degassing of metals; Engineering; grain refinement; primary silicon; master alloy; alp compound; Machines; Manufacturing; Materials Engineering; Metallic Materials; Metals; Processes; Research & Development; Silicon; Specialty metals industry; master alloy; AlP compound; A; grain refinement; primary silicon; TG146.21
• ISSN: 1672-6421; 2365-9459; 1672-6421
• DOI: 10.1007/s41230-021-0074-2

The grain refinement behavior of Si-3P, Si-25Mn-10P, and Al-10Si-2Fe-3P master alloys on hypereutectic Al-24Si alloy was studied. Microstructure analysis indicates that the P-containing compounds in the three master alloys are SiP, MnP, and AlP, respectively. The coarse flower-like primary silicon in the Al-24Si alloy transforms into smaller, well-distributed blocks with the addition of various master alloys. When pouring at 840 °C, the average grain size of the primary silicon refined by Si-25Mn-10P master alloy with a holding time of 30 min is about 18 µm, which is significantly smaller than those refined by Si-3P and Al-10Si-2Fe-3P master alloys. The grain size shows an increasing trend when the holding time is further prolonged. Higher holding temperature has a positive effect on the grain refinement of Si-25Mn-10P master alloy. The grain refinement mechanism of the three master alloys was also discussed.