Direct solid-state diffusion bonding of zirconium carbide using a spark plasma sintering system
Direct solid-state diffusion bonding of zirconium carbide using a spark plasma sintering system
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DOI：
10.1016/j.matdes.2016.08.060
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发表时间：
2016-11
影响因子：
8.4
通讯作者：
K. Kohama;Kazuhiro Ito
中科院分区：
文献类型：
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作者：
K. Kohama;Kazuhiro Ito
采用放电等离子烧结系统对平均晶粒尺寸为3.5、7.5和35 μm的碳化锆（ZrC）烧结材料进行了直接固态扩散连接。ZrC样品在1300-2000 °C下结合20分钟，没有缺陷或氧化。在室温下对ZrC-ZrC接头的剪切试验表明，通过减小ZrC平均晶粒尺寸，可以降低获得在结合界面处具有高于基体材料的断裂强度的接头的结合温度。结合界面周围的微结构研究表明，结合过程由晶界扩散控制，并且主要驱动力是晶界和结合界面的交叉处的降低的边界能（即，接合界面处的三重结）。晶界迁移跨越粘接界面的三重连接建议，以增加接头强度。由减小的ZrC晶粒尺寸产生的较高密度的三重连接被认为增强了晶界迁移，并增加了晶界扩散的驱动力和扩散路径，这导致形成具有较高结合界面强度的接头。
The authors conducted direct solid-state diffusion bonding of zirconium carbide (ZrC)-sintered materials with different average grain sizes of 3.5, 7.5 and 35 μm using a spark plasma sintering system. ZrC samples were bonded at 1300–2000 °C for 20 min with no defects or oxidation. Shear tests on the ZrC–ZrC joints at room temperature revealed that the bonding temperature to obtain joints with a strength at the bonding interface that is higher than the fracture strength of the base materials could be reduced by reducing the ZrC average grain size. Microstructure studies around the bonding interface showed that the bonding process was controlled by grain-boundary diffusion, and the dominant driving force was a lowering boundary energy at the intersection of the grain boundary and the bonding interface (i.e., triple junctions at the bonding interface). Grain boundary migration across the bonding interface at the triple junctions was suggested to increase joint strength. The higher density of the triple junctions derived from the reduced ZrC grain size is thought to enhance grain boundary migration and increase the driving force and diffusion paths for grain boundary diffusion, which results in the formation of joints with a higher bonding interface strength.