中國有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 13 No. 6 December 2003 |
T. Kanno(菅野利猛)2, H. Nakae(中江秀雄)3
（1. State Key Laboratory of Mould and Dies Technology，
Huazhong University of Science and Technology，Wuhan 430074，China;
2. Kimura Foundry Co Ltd, Shizuoka 411, Japan;
3. Department of Materials Science and Engineering,
Waseda University, Tokyo 169, Japan）
Abstract:Effect of P-Na united modification on Al-22%Si-1.0%Cu-0.5%Mg-0.5%Mn alloy was studied. The results show that the refining effect of P-Na addition on primary silicon is superior to that of P and the former could modify eutectic silicon at the same time. Effects of P-Na modification on crystallization and microstructure of hypereutectic Al-Si alloys were studied with Electron-Scanning Microscope, Electron-Probe and X-ray diffractometer. The modification mechanism represents that on one hand, the primary silicon is refined by AlP as heterogeneous nucleus; on the other hand, when Na is added at the same time, P atoms are difficult to diffuse in the melt, and then enrichs on the growing faces of silicon phase. Moreover, a SiP compound was also discovered in Si crystals, which prevents the growth of silicon phase and refines the primary silicon.
附件:yw2003-06-07
Key words: hypereutectic Al-Si alloys; modification mechanism; grain refinement; modification
