Graphene reinforced alumina nano-composites
Graphene reinforced alumina nano-composites
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DOI：
10.1016/j.carbon.2013.07.086
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发表时间：
2013-11-01
期刊：
影响因子：
10.9
通讯作者：
Reece, Mike J.
中科院分区：
文献类型：
--
作者：
Porwal, Harshit;Tatarko, Peter;Reece, Mike J.
石墨烯采用液相剥离法制备，并采用超声处理和粉末加工路线分散在氧化铝基质中。使用 SPS 将含量高达 5 vol% 的 Al2O3-石墨烯复合材料致密化 (>99%)。仅添加0.8 vol%的石墨烯，材料的断裂韧性就增加了40%。然而，对于较高的石墨烯含量，断裂韧性的改善是有限的。石墨烯改变了氧化铝基体的裂纹扩展机制，从晶间扩展为跨晶。当浓度 >= 2 vol% 时，互连石墨烯网络的形成促进了容易断裂。由于互连石墨烯网络的形成，弹性模量在高达 2 vol% 的情况下几乎保持恒定，并且在 5 vol% 的情况下显着下降。使用压痕法和 V 形缺口法测量的断裂韧性在 2 vol% 以内保持一致，而在 5 vol% 时，石墨烯的渗透网络导致裂纹容易扩展，两种方法的结果之间存在显着差异。 Crown 版权所有 (C) 2013 由 Elsevier Ltd 出版。保留所有权利。
Graphene was prepared using liquid phase exfoliation and dispersed in an alumina matrix using an ultrasonication and powder processing route. Al2O3-graphene composites with up to 5 vol% content were densified (>99%) using SPS. The fracture toughness of the material increased by 40% with the addition of only 0.8 vol% graphene. However for higher graphene contents the improvement in fracture toughness was limited. Graphene changed the mechanism of crack propagation for the alumina matrix from inter-granular to trans-granular. The formation of an inter-connecting graphene network promoted easy fracture for concentration >= 2 vol%. Elastic modulus remained nearly constant for up to 2 vol% and decreased significantly for 5 vol% due to the formation of the inter-connecting graphene network. Fracture toughness measured with the indentation and chevron notch methods were consistent up to 2 vol% and at 5 vol% the percolating network of graphene resulted in easy crack propagation with significant discrepancy between the results for the two methods. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.