open access

https://hdl.handle.net/2115/74620

Modification of hipereutectic Al-Si alloys by the Duplex Casting process with addition of Na and P

日本語

solidification

1992-03-30

軽金属学会

Journal of Japan Institute of Light Metals

42(3)

132-137

Modification of Al-22mass%Si and Al-22mass%Si-2.5mass%Mg alloys was examined by combined use of the Duplex Casting process and addition of Na and P. In the Duplex Casting process, two kinds of alloy melts with different compositions were cast in the mold at a given interval. In this study, the combinations of Na-treated Al-12mass%Si alloy or Na-treated Al-12mass%Si-5mass%Mg alloy as the first melt and P-treated Al-32mass%Si alloy as the second melt were used. In the conventional casting, simultaneous addition of Na and P tends to coarsen the primary silicon crystal. On the other hand, refined primary silicon crystals and modified eutectic silicon crystals are observed in the ingots obtained by combined use of the Duplex Casting process and addition of Na and P. In the vicinity of the side surface of the ingots, markedly refined primary silicon crystals are observed, which show the synergistic effect of the Duplex Casting process and P addition to the second melt. Origin of "Primary Silicon Free Zone" in the ingots is the first melt incompletely mixed. Acceleration of circulation flow of the second melt in the mold alleviates the macrosegregation of primary silicon.

学術雑誌論文

Version of Record

0451-5994

AN00669773