Solidification Behavior of in situ TiB2/Cu Composite Powders during Reactive Gas Atomization
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2021年第2期
论文作者：姜伊辉 ZHANG Mingshu LI Yufa HE Jiangtan CAO Fei 梁淑华
文章页码：203 - 208
摘 要：2wt% TiB2/Cu composite powders were fabricated in situ by reactive gas atomization.The fabricated composite powder exhibits high sphericity,and the powder sizes range from 5 μm to 150 μm.The morphology of the Cu matrix and the distribution of the TiB2 particles in the composite powders vary with the powder size.The critical transitions of interface morphologies from dendritic-to-cellular and cellular-to-planar interfaces occurs when the composite powder sizes decrease to 34 μm and 14 μm,respectively.Compared with pure Cu droplets,the composite droplets undergo critical transition of the interface morphologies at a smaller droplet size corresponding to a higher cooling rate because the existence of TiB2 particles can cause instability in the advancing solidification front and heterogeneous nucleation.With decreasing powder size,the extent of the TiB2 particle interdendritic segregation decreases as the result of enhanced engulfment of TiB2 particles by the advancing solidification front.
姜伊辉，ZHANG Mingshu，LI Yufa，HE Jiangtan，CAO Fei，梁淑华
Shaanxi Province Key Laboratory for Electrical Materials and Infiltration Technology, Xi’an University of Technology
摘 要：2wt% TiB2/Cu composite powders were fabricated in situ by reactive gas atomization.The fabricated composite powder exhibits high sphericity,and the powder sizes range from 5 μm to 150 μm.The morphology of the Cu matrix and the distribution of the TiB2 particles in the composite powders vary with the powder size.The critical transitions of interface morphologies from dendritic-to-cellular and cellular-to-planar interfaces occurs when the composite powder sizes decrease to 34 μm and 14 μm,respectively.Compared with pure Cu droplets,the composite droplets undergo critical transition of the interface morphologies at a smaller droplet size corresponding to a higher cooling rate because the existence of TiB2 particles can cause instability in the advancing solidification front and heterogeneous nucleation.With decreasing powder size,the extent of the TiB2 particle interdendritic segregation decreases as the result of enhanced engulfment of TiB2 particles by the advancing solidification front.
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