Role of synthesis method on microstructure and mechanical properties of graphene/carbon nanotube toughened Al2O3 nanocomposites
Role of synthesis method on microstructure and mechanical properties of graphene/carbon nanotube toughened Al2O3 nanocomposites
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DOI：
10.1016/j.ceramint.2015.04.054
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发表时间：
2015-09-01
影响因子：
5.2
通讯作者：
Zhu, Yanqiu
中科院分区：
文献类型：
--
作者：
Yazdani, Bahareh;Porwal, Harshit;Zhu, Yanqiu
研究了热压（HP）和放电等离子烧结（SPS）方法对石墨烯纳米片/碳纳米管（GNTs）增强Al 2 O3纳米复合材料的晶粒尺寸、显微结构和力学性能的影响。选择不同的石墨烯纳米片与碳纳米管的比率作为使用HP和SPS制备的复合材料的总增强含量。在1650 ℃、40 MPa、Ar气氛下，HP和SPS的停留时间分别为1 h和10 min，获得了高度致密的样品（> 98%）。这两种类型的样品表现出混合物的晶间和穿晶断裂行为。与SPS样品相比，观察到HP制备的样品的晶粒尺寸减小了50%。这两种类型的样品都实现了> 400 MPa和5.5 MPa m（1/2）的高弯曲强度和断裂韧性，而SPS样品在相对较低的GNT含量下达到峰值。通过对复合材料的微观形貌、晶粒尺寸和断裂方式的分析，发现两种材料的增韧机理相似，但复合材料的增韧机理复杂。(C)2015 Elsevier Ltd和Techna Group S.r.l. All rights reserved.
The effects of hot-pressing (HP) and spark plasma sintering (SPS) methods on the grain size, microstructural features, and mechanical behaviour of graphene nanoplatelet/carbon nanotubes (GNTs) reinforced Al2O3 nanocomposites were comprehensively studied. Different graphene nanoplatelet to carbon nanotube ratios were selected as the overall reinforcement content of composites prepared using HP and SPS. Highly densified samples (> 98%) were obtained at 1650 degrees C under 40 MPa in Ar atmosphere, with dwell times of 1 h and 10 min for HP and SPS respectively. Both types of sample showed a mixture of inter- and transgranular fracture behaviour. A 50% grain size reduction was observed for samples prepared by HP compared to SPS samples. Both types of samples achieved a high flexural strength and fracture toughness of > 400 MPa and 5.5 MPa m(1/2), whilst SPS samples peaked at relatively lower GNT contents than those for the HP samples. Based on analyses of the morphology, grain sizes and fracture mode, similar toughening mechanisms for both types of sample were observed, involving the complex characteristics of the combined GNT fillers. (C) 2015 Elsevier Ltd and Techna Group S.r.l. All rights reserved.