摘要
Microstructure evolution of Ni-24.19 wt%Nb hypereutectic alloys was investigated to develop a method to increase the productivity of in situ composite in directional solidification. The results show that at the constant growth velocity of 10 μm/s, coarse priamry β-Ni3Nb plate dendrites were firstly precipitated from the liquid. However, at the growth velocity changing abruptly from 1 μm/s to 10 μm/s, only coupled growth eutectics were observed in the solidification microstructure. The coupled eutectic growth stable at 10 μm/s is possibly ascribed to the interface growth temperature of coupled eutecitc exceeding that of β-Ni3Nb single phase. Another probable factor to permit the coupled eutectic growth stable at 10 μm/s is the difficult nucleation of β-Ni3Nb phase in front of the eutectic growth interface. By changing solidification process, the productivity for the formation of in situ composite of Ni-24.19 wt%Nb hypereutectic alloy is improved by a factor of 5.
源语言 | 英语 |
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页(从-至) | 117-123 |
页数 | 7 |
期刊 | Materials Science and Engineering: A |
卷 | 475 |
期 | 1-2 |
DOI | |
出版状态 | 已出版 - 25 2月 2008 |