Densification of powder compacts: An unfinished story
Densification of powder compacts: An unfinished story
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DOI：
10.1016/j.jeurceramsoc.2007.12.016
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发表时间：
2008
影响因子：
5.7
通讯作者：
F. Lange
中科院分区：
文献类型：
--
作者：
F. Lange
这篇综述的重点是总结为什么粗化的晶粒和孔隙伴随着致密化的粉末压坯的理解。综述将首先总结简单粒子阵列的热力学研究，这表明，在致密之前，初始接触粒子之间的颈部生长停止。分析和计算机研究的结果，关于晶粒生长发生在部分致密的粉末压坯将进行审查，以表明晶粒粗化将重新启动颈部生长过程负责进一步收缩。然后将对实验结果进行审查，并将其与分析研究相关联。它将被证明，连接到最大数量的晶界，即快速质量传输的途径，孤立的孔隙将首先消失。最后，孔隙周期性的缺乏将限制一个区域相对于另一个区域的收缩。
The focus of this review is to summarize the understanding of why the coarsening of grains and pores accompanies the densification of a powder compact. The review will initiate with a summary of the thermodynamic studies of simple particle arrays, which suggests that the growth of necks between the initial touching particles stop before the compact is dense. Results of analytical and computer studies concerning how grain growth occurs in partially dense powder compacts will be reviewed to show that grain coarsening will reinitiate the neck growth process responsible for further shrinkage. Experimental results will then be reviewed and related to the analytical studies. It will be shown that isolated pores connected to the largest number of grain boundaries, namely, avenues for rapid mass transport, will disappear first. Finally, the lack of pore periodicity will constrain the shrinkage of one region relative to another.