Observation of particle behavior in copper powder compact during pulsed electric discharge
Observation of particle behavior in copper powder compact during pulsed electric discharge
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DOI：
10.1016/s0921-5093(02)00726-8
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发表时间：
2003-06
期刊：
影响因子：
6.4
通讯作者：
O. Yanagisawa;H. Kuramoto;K. Matsugi;M. Komatsu
中科院分区：
文献类型：
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作者：
O. Yanagisawa;H. Kuramoto;K. Matsugi;M. Komatsu
在光学显微镜下观察了500 ms单脉冲放电过程中，粉末压坯中均匀尺寸（平均直径550 μm）的球形铜粉颗粒的行为。在扫描电子显微镜下观察粉末颗粒之间形成的颈部的形态，并测量其直径。得到的结果总结如下：压力和脉冲电流密度决定是否发生火花。在低压和高电流密度下，火花更容易发生在颗粒间接触处。在火花产生的地方，粒子通过熔化结合在一起。无论是否观察到火花，在颗粒之间的接触点处形成颈部，并且颈部直径随着脉冲电流密度而增加。这些结果表明，微观火花，熔化和汽化发生的装置，通过在压实的初始阶段的颗粒间接触的局部发热达到极高的温度。
The behavior of spherical copper powder particles of uniform size (average diameter: 550 μm) in a powder compact was observed under an optical microscope during a single-pulse electric discharge of 500 ms duration. The morphologies of necks formed between powder particles were observed under a scanning electron microscope, and their diameters were measured. The results obtained are summarized as follows: pressure and pulsed current density determine whether or not a spark occurs. Spark is more likely to occur at interparticle contacts under low pressure and high current density. Where a spark occurs, particles are joined together by melting. Regardless of whether or not a spark is observed, necks are formed at points of contact between particles and neck diameter increases with pulsed current density. These results suggest that microscopic sparking, melting, and vaporization occur by means of extremely high temperature attained by local heat generation at the interparticle contacts in the initial stage of compaction.