Microstructure of undercooled Pb-Sn alloys

[摘要] Melt undercooling opens new solidification pathways for new non-equilibrium phases and non-conventional microstructures. Several techniques have been developed in order to reduce nucleation sites and to produce high undercoolings for metals and alloys including the fluxing technique. In this study: the fluxing technique was applied to hypoeutectic, eutectic and hypereutectic Pb-Sn alloys. For hypereutectic alloy, a morphological change occurs with increasing undercooling and is accompanied by a refinement of the primary dendrites beta Sn phase. For alloys studied, the eutectic has exhibited anomalous morphology with increasing undercooling, DeltaT(e). The results indicated that the critical undercooling, DeltaT(e)* that causes a transition from lamellar eutectic to anomalous eutectic in the Pb-Sn alloys is around 6 K. (C) 2001 EIsevier Science All rights reserved.

[发布日期] 2001-05-31

[效力级别]  Proceedings Paper

[关键词] undercooling;Pb-Sn alloys;fluxing technique;solidification