Silicon nitride nanoceramics densified by dynamic grain sliding
Silicon nitride nanoceramics densified by dynamic grain sliding
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DOI：
10.1557/jmr.2010.0313
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发表时间：
2010-12
影响因子：
2.7
通讯作者：
M. Herrmann;Z. Shen;I. Schulz;Jianfeng Hu;B. Jaňcar
中科院分区：
文献类型：
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作者：
M. Herrmann;Z. Shen;I. Schulz;Jianfeng Hu;B. Jaňcar
研究了以α-Si_3N_4和α-Si_3N_4为主要相的两种氮化硅纳米粉体混合物的放电等离子烧结致密化行为。建立烧结条件，其中不与主要结晶组分平衡的低粘度液体刺激晶粒滑动，但不激活可避免地产生晶粒生长的再沉淀机制。采用这种动态晶粒滑移的方法，在不发生α-Si_3N_4向β-Si_3N_4的相变和晶粒长大的情况下，实现了氮化硅纳米陶瓷的完全致密化。这一工艺原理为实现Si_3N_4陶瓷微观结构和性能的灵活、精确定制开辟了道路。所得氮化硅纳米陶瓷显示出改善的耐磨性，特别是在较高的赫兹应力下。
The densification behaviors of two silicon nitride nanopowder mixtures based respectively on α-Si_3N_4 and ß-Si_3N_4 as the major phase constituent were studied by spark plasma sintering. Sintering conditions were established where a low viscous liquid not in equilibrium with the main crystalline constituent(s) stimulated the grain sliding yet did not activate the reprecipitation mechanism that unavoidably yields grain growth. By this way of dynamic grain sliding full densification of silicon nitride nanoceramics was achieved with no noticeable involvement of α- to β-Si_3N_4 phase transformation and grain growth. This processing principle opens the way toward flexible and precise tailoring of the microstructures and properties of Si_3N_4 ceramics. The obtained silicon nitride nanoceramics showed improved wear resistance, particularly under higher Hertzian stresses.