TY - JOUR
T1 - Combining Sr and Na additions in hypoeutectic Al-Si foundry alloys
AU - Lu, Liming
AU - Nogita, K.
AU - Dahle, A. K.
N1 - Funding Information:
The authors would like to acknowledge the financial support of the Cooperative Research Centre for Cast Metals Manufacturing (CAST). CAST was established and is supported by the Australian Government's Cooperative Research Centres Program. LSM and Comalco are acknowledged for supplying the master alloys and the commercial purity aluminium ingot, respectively, and Elkem Silicon for supplying the silicon used in this research.
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2005/6/15
Y1 - 2005/6/15
N2 - From recent published data, it is still unclear whether combining additions of Na and Sr have synergistic effects or deleterious interactions. This paper clarifies the interactions between these two modifiers and investigates the effects of such interactions on alloy solidification and castability. It was found that combined additions of Sr and Na do not appear to cause improvement of the modification of the eutectic microstructure even after only a short period after addition. Na addition may promote Sr vaporization and/or oxidation kinetically, leading to a quicker loss of both modifiers, which is blamed for the rapid loss of the modification effect during melt holding. Quenching trials during the eutectic arrest indicate that addition of Sr into Na-modified melts does not alter the eutectic solidification behaviour. The effect of Na on eutectic solidification dominates, and the eutectic is observed to evolve with a significant dependency on the thermal gradient. Combining Sr and Na additions produced no beneficial effects on porosity and casting defects.
AB - From recent published data, it is still unclear whether combining additions of Na and Sr have synergistic effects or deleterious interactions. This paper clarifies the interactions between these two modifiers and investigates the effects of such interactions on alloy solidification and castability. It was found that combined additions of Sr and Na do not appear to cause improvement of the modification of the eutectic microstructure even after only a short period after addition. Na addition may promote Sr vaporization and/or oxidation kinetically, leading to a quicker loss of both modifiers, which is blamed for the rapid loss of the modification effect during melt holding. Quenching trials during the eutectic arrest indicate that addition of Sr into Na-modified melts does not alter the eutectic solidification behaviour. The effect of Na on eutectic solidification dominates, and the eutectic is observed to evolve with a significant dependency on the thermal gradient. Combining Sr and Na additions produced no beneficial effects on porosity and casting defects.
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U2 - 10.1016/j.msea.2005.03.091
DO - 10.1016/j.msea.2005.03.091
M3 - Article
AN - SCOPUS:23344446301
VL - 399
SP - 244
EP - 253
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
IS - 1-2
ER -