Carbon nanotube toughened hydroxyapatite by spark plasma sintering: Microstructural evolution and multiscale tribological properties
Carbon nanotube toughened hydroxyapatite by spark plasma sintering: Microstructural evolution and multiscale tribological properties
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DOI：
10.1016/j.carbon.2010.04.047
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发表时间：
2010-09-01
期刊：
影响因子：
10.9
通讯作者：
Agarwal, Arvind
中科院分区：
文献类型：
--
作者：
Lahiri, Debrupa;Singh, Virendra;Agarwal, Arvind
研究了火花等离子烧结法制备的碳纳米管增强羟基磷灰石复合材料。定量显微结构分析表明，CNTs在晶界固定中发挥作用，并在烧结球团的整个厚度上改善了纳米结构的致密性和保留性。透明质酸晶体与碳纳米管形成相干界面，形成强界面键。与不含碳纳米管的HA基体相比，在HA基体中均匀分布4 wt.%的CNTs、良好的界面结合和细小的HA晶粒尺寸有助于将断裂韧性提高92%，弹性模量提高25%。从界面剪切强度和碳纳米管从HA基体中拔出能量的角度解释了增韧机制。碳纳米管在宏观和纳米尺度上都对提高羟基磷灰石基体的耐磨性起着重要作用。综上所述，碳纳米管表面的石墨烯层脱落发生在宏观磨损过程中，而不是在纳米磨损过程中。因此，ha -碳纳米管的摩擦系数（CoF）在宏观磨损中降低，这是由于分层的石墨烯层提供了润滑。(C) 2010 Elsevier Ltd.版权所有。
Carbon nanotube (CNT) reinforced hydroxyapatite (HA) composite synthesized using spark plasma sintering is investigated in this study. Quantitative microstructural analysis suggests that CNTs play a role in grain boundary pinning and are responsible for the improved densification and retention of nanostructure throughout the thickness of the sintered pellet. HA crystal forms coherent interface with the CNT, resulting in a strong interfacial bond. The uniform distribution of 4 wt.% CNTs in the HA matrix, good interfacial bonding and fine HA grain size help to improve the fracture toughness by 92% and elastic modulus by 25% as compared to the HA matrix without CNT. Toughening mechanisms have been explained in terms of interfacial shear strength and pull-out energy of CNT from the HA matrix. CNT plays a major role in improving the wear resistance of HA matrix at both macro- and nano-scale. It is concluded that graphene layer removal from the CNT surface occurs during macro-wear, but not for nano-wear. Thus, the coefficient of friction (CoF) in HA-CNT decreases in macro-wear due to lubrication available through delaminated graphene layers. (C) 2010 Elsevier Ltd. All rights reserved.