Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1548708 | Progress in Natural Science: Materials International | 2009 | 6 Pages |
Abstract
High undercooling (about 392Â K) was achieved in the bulk eutectic Ni70.2Si29.8 alloy melt through glass fluxing combined with cyclic superheating. It is found that the metastable phases Ni3Si2 and NiSi are obtained through slow post-solidification when undercooling exceeds 240Â K. The metastable phases are confirmed by using the method of X-ray diffraction and differential scanning calorimetry (DSC). Based on the principle of the free energy minimum and the transient nucleation theory, the phase selection of melt is investigated with regard to the metastable phases formation in the bulk undercooled eutectic Ni70.2Si29.8 melts. The formation of metastable phases from undercooled Ni70.2Si29.8 melts is ascribed to competitive nucleation with the undercooling, i.e. high undercooling facilitates the preferential nucleation of metastable phases.
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Authors
Yiping Lu, Tingju Li, Fu Yabo, Sun Jianbo, Luo Dawei, Gencang Yang, Yaohe Zhou,