Relationship between microstructure and mechanical properties in acid-treated carbon nanotube-reinforced alumina composites
Relationship between microstructure and mechanical properties in acid-treated carbon nanotube-reinforced alumina composites
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DOI：
10.1007/s10853-015-9223-6
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发表时间：
2015-10-01
影响因子：
4.5
通讯作者：
Hashida, Toshiyuki
中科院分区：
文献类型：
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作者：
Shirasu, Keiichi;Yamamoto, Go;Hashida, Toshiyuki
氧化铝复合材料增强多壁碳纳米管（MWCNTs）在高达3.7体积%的制备通过前驱体的方法，然后通过放电等离子体烧结。我们系统地和定量地研究了多壁碳纳米管的酸处理时间不仅对复合材料的弯曲强度和断裂韧性的影响，而且对多壁碳纳米管的机械强度和断裂韧性、氧化铝基体的晶粒尺寸以及多壁碳纳米管与氧化铝之间的界面强度的影响。本研究的主要目的是评估这些参数如何影响机械性能的多元回归分析的帮助。我们表明，基体晶粒尺寸，多壁碳纳米管的机械强度，和界面强度在这项研究中制备的复合材料的机械性能的影响不大。另一方面，MWCNTs的热处理对复合材料的力学性能有着重要的影响。在低MWCNT含量（0.9体积%）下，随着酸处理时间增加至2 h，MWCNT的分散性和复合材料的力学性能均增加。相反，在较高量的MWCNT下，机械性能的劣化被示出与MWCNT的可变形性的劣化相关。由于预期MWCNT团聚体作为缺陷，它们可能超越MWCNT的强度、基质粒度和界面强度的影响。通过多元回归分析，定量地表明了提高MWCNT/Al_2O_3复合材料的力学性能的最重要因素之一是MWCNT的结晶度。
Alumina composites reinforced with multiwalled carbon nanotubes (MWCNTs) at up to 3.7 vol% are prepared by a precursor method followed by a spark plasma sintering. We systematically and quantitatively investigate the effects of acid-treatment time of the MWCNTs on not only bending strength and fracture toughness of the composites but also on the mechanical strength and dispersibility of the MWCNTs, the grain size of the alumina matrix, and the interfacial strength between MWCNT and alumina. The main objective of this study is to evaluate how these parameters influence the mechanical properties with the aid of multiple regression analysis. We demonstrate that the matrix grain size, the mechanical strength of the MWCNTs, and the interfacial strength have little impact on the mechanical properties for the composites prepared in this study. On the other hand, the dispersibility of MWCNTs has the significant influence on the mechanical properties. Both the dispersibility of the MWCNTs and the mechanical properties of the composites increase as the acid-treatment time increases up to 2 h at low MWCNT content (0.9 vol%). Conversely, at a higher amount of MWCNTs, the degradation in the mechanical properties is shown to be associated with the deterioration of MWCNTs' dispersibility. As MWCNT agglomerates are anticipated to act as imperfections, they may override the effects of the strength of MWCNTs, matrix grain size, and interfacial strength. By means of the multiple regression analysis, we quantitatively show that improving MWCNTs' dispersibility is one of the most important factors in enhancing the mechanical properties of MWCNT/alumina composites.