PREPARATION OF AL2O3/NI COMPOSITES BY PRESSURELESS SINTERING IN H-2
PREPARATION OF AL2O3/NI COMPOSITES BY PRESSURELESS SINTERING IN H-2
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DOI：
10.1016/0272-8842(95)99785-a
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发表时间：
1995-01-01
影响因子：
5.2
通讯作者：
WU, HH
中科院分区：
文献类型：
--
作者：
TUAN, WH;LIN, MC;WU, HH
脆性固体可以通过引入韧性夹杂物而变韧。本研究通过还原Al_2O_3和NiO粉末混合物或还原Al_2O_3/NiAl_2O_4压坯制备Al_2O_3/Ni复合材料。测定了Al_2O_3/Ni复合材料的弯曲强度和断裂韧性。由于氧化铝和镍之间的热膨胀失配，当镍夹杂物大于2 μ m时，在界面处形成环向裂纹。复合材料的韧性通过裂纹桥接机制或微裂纹增韧而增强。但是，随着微裂纹的形成，Al_2O_3/Ni复合材料的强度显著下降。
Brittle solids can be toughened by introducing ductile inclusions. In the present study, Al2O3/Ni composites are prepared by reducing Al2O3 and NiO powder mixtures or by reducing Al2O3/NiAl2O4 compacts in hydrogen. The flexural strength and fracture toughness of the Al2O3/Ni composites are determined. Due to the thermal expansion mismatch between alumina and nickel, a circumferential crack is formed at the interface as the nickel inclusion is larger than 2 mu m. The toughness of the composites is enhanced by a crack bridging mechanism or by microcrack toughening. However, the strength of the Al2O3/Ni composites is decreased significantly as the microcracks are formed.