The phase transition of ZrP induced by Si in Al-Si melts

In this article, the reaction process of ZrP in Al-Si melts was investigated, and by the results of XRD, EDS and FESEM, the AlP and (Al, Zr, Si) phases were observed, indicating that the phase transition of ZrP phase has carried out in Al melts induced by Si. Detailed investigation confirmed that the finer particle of (Al, Zr, Si) phase is the type of ZrAl3 doped with trace Si and the coarser block is the type of ZrSi2 doped with trace Al. Furthermore, it is found that when the ZrP phase was added into Al-Si melts, Si atoms accumulated around ZrP phase, forming Si deficiency-layer and Si enrichment-layer. The concentration gradient of Si leads to two types of transition process of the ZrP phase in Al melt. Finally, the reaction mechanism of ZrP with Al-Si alloys was analyzed. (C) 2012 Elsevier B.V. All rights reserved.