Abstract

In this article, the tribological properties of aluminum/MWCNTs/Al₂O_3sf hybrid composites with varying volume fraction of 10 vol%, 15 vol% and 20 vol% was investigated under dry sliding conditions. The experiments were performed according to design of experiments approach using Taguchi method to predict the wear properties of composites. The results indicated that the composites of 15 vol% had lower wear loss, whereas the coefficient of friction (COF) decreased significantly at 20 vol%. Taguchi based ANOVA analysis showed that the sliding distance was found to be the prominent factor controlling the wear loss; applied load influenced COF most significantly. It could also be noticed that the COF and wear loss increases with an increase in sliding load and sliding distance. The decrease in wear loss and the COF can be attributed to the self-lubrication effect of MWCNTs, and the combined effect of reinforcements in the composites. In addition, nanoscratch test was performed to determine the COF and the effect of the reinforcements on local regions of the composites. The results revealed that higher friction force was obtained near the regions of MWCNTs and Al₂O_3sf while nanoscratching. The COF of composites of 20 vol% was found to slightly higher compared to that of 10 vol% and 15 vol%. This is attributed to the presence of MWCNTs cluster within the Al₂O_3sf network results prevent the micro-plastic deformation of Al matrix, and the formation of tribofilms with nanoscaled thickness in the scratch region. These friction and wear results indicate that the presence of a limited amount and size of MWCNTs clusters are beneficial to the tribological properties of the hybrid composites.

Graphic Abstract

中文翻译：

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MWCNTs /氧化铝纤维增强铝基杂化复合材料的摩擦学和纳米划痕性能

摘要

在本文中，铝/ MWCNTs / Al ₂ O _3sf的摩擦学性能在干滑条件下研究了体积分数分别为10 vol％，15 vol％和20 vol％的杂化复合材料。根据实验方法的设计，使用田口方法进行实验以预测复合材料的磨损性能。结果表明，含量为15％（体积）的复合材料磨损损耗较低，而摩擦系数（COF）在含量为20％（体积）时明显降低。基于Taguchi的ANOVA分析表明，滑动距离是控制磨损损失的主要因素。外加负载对COF的影响最大。还可以注意到，COF和磨损损失随着滑动载荷和滑动距离的增加而增加。磨损损失和COF的降低可归因于MWCNT的自润滑作用，以及复合材料中增强材料的综合作用。另外，进行了纳米划痕试验以确定COF和增强物对复合材料局部区域的影响。结果表明，在多壁碳纳米管和铝附近获得了较高的摩擦力。纳米_刮擦时为₂ O _3sf。发现复合材料的COF为20体积％，而10体积％和15体积％则更高。这归因于在Al ₂ O _3sf网络中存在MWCNTs团簇，结果阻止了Al基体的微塑性变形，并在划痕区形成了纳米级厚度的摩擦膜。这些摩擦和磨损结果表明，有限数量和大小的MWCNT簇的存在有利于杂化复合材料的摩擦学性能。

图形摘要