Possibility of enhanced strength and self-recovery of surface damages of ceramics composites under oxidative conditions
Possibility of enhanced strength and self-recovery of surface damages of ceramics composites under oxidative conditions
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氧化条件下陶瓷复合材料表面损伤增强和自我恢复的可能性
DOI：
10.1016/j.jeurceramsoc.2005.06.020
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发表时间：
2006
影响因子：
5.7
通讯作者：
Yoichiro Kuranobu
中科院分区：
文献类型：
--
作者：
O. Abe;Y. Ohwa;Yoichiro Kuranobu
NiAl/α-Al_2O_3复合材料的氧化过程中，表面层由NiAl_2O_4和Al_2O_3晶粒组成，并产生压应力。通过在1200-1300°C下控制变质层的发展，能够从515 MPa和4 MPam 1/2（烧结）强化和韧化到10655 MPa和106 MPam 1/2（氧化）。氧化产物NiO与基体Al 2 O3的反应以及沿沿着晶界的快速扩散，通过填充和重新结合缺陷和裂纹来修复表面损伤。氧化通过修复的缺陷进一步发展，以形成支持它们的变质层，从而提高强度的恢复。含缺陷材料的强度由150 MPa下降到531 MPa，而在Ar气氛中热修复后的强度仅恢复到343 MPa。
Oxidation of NiAl/α-Al2O3composites provides the metamorphic surface layers consisting of boundary NiAl2O4and Al2O3grains with compressive stress. Strengthening and toughening from 515MPa and 4MPam1/2(sintered) to ∼655MPa and ∼6MPam1/2(oxidized) are enabled by a controlled development of the metamorphic layers at 1200–1300°C. The reactivity of an oxidation product, NiO, with the matrix-Al2O3and the rapid diffusion along the grain boundary repairs the damages on surfaces by filling and re-bonding the defects and cracks. The oxidation further progresses via the repaired defects to develop the metamorphic layers supporting them to enhance the recovery of the strength. The degraded strength of the material with defects, 150MPa, is recovered to 531MPa by the reparation against the limited recovery to 343MPa by a thermal healing in Ar.