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论文类型：期刊论文

发表时间：2009-02-19

发表刊物：JOURNAL OF MATERIALS PROCESSING TECHNOLOGY

收录刊物：SCIE、EI、Scopus

卷号：209

期号：4

页面范围：2092-2098

ISSN号：0924-0136

关键字：Rheocasting; A356 alloy; Microstructure; Copious nucleation

摘要：A novel approach, was designed to obtain thixotropic structure of equiaxed or non-dendrtic grains for rheocasting, and demonstrated experimentally using A356 aluminum alloy. The circumstance in bulk liquid metal, which would burst into copious nucleation, and at the same time create homogeneous distribution of temperature and solute, was constructed by combined utilization of rotating magnetic fields and a cooling tube. Both the solidified microstructures in metal mold and sand mold exhibited non-dendritic characteristic. Analyses of the rheocasting A356 microstructure indicated that high density of nuclei occurred by inserting a cooling tube into rotating slurry at liquidus temperature. In the case of slow cooling rate, mushy slurry obtained with high nuclei density kept non-dendritic morphology of primary particles with holding time, accompanying grain particles' coarsening and spheroidizing; moreover, the eutectic silicon got coarsening with retaining time. (C) 2008 Elsevier B.V. All rights reserved.