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.
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The authors gratefully acknowledge the support of the National Natural Science Foundation of China (51974057 and 5174057), the Open Project of State Key Laboratory of Advanced Special Steel, Shanghai Key Laboratory of Advanced Ferrometallurgy, Shanghai University (SKLASS 2019-19) and the Science and Technology Commission of Shanghai Municipality (No. 19DZ2270200).
Peng-ting Li Male, Ph.D., Associate Professor. He is engaged in the research on microstructure modification and solidification control of Al-Si alloys and superalloys.
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Njuguna, B.K., Li, Jy., Tan, Y. et al. Grain refinement of primary silicon in hypereutectic Al-Si alloys by different P-containing compounds. China Foundry 18, 37–44 (2021). https://doi.org/10.1007/s41230-021-0074-2
- grain refinement
- primary silicon
- master alloy
- AlP compound