Rapid microwave sintering of carbon nanotube-filled AZ61 magnesium alloy composites
Rapid microwave sintering of carbon nanotube-filled AZ61 magnesium alloy composites
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DOI：
10.1016/j.compositesb.2016.03.041
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发表时间：
2016-05-15
影响因子：
13.1
通讯作者：
Tsui, Chi-Pong
中科院分区：
文献类型：
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作者：
Akinwekomi, Akeem Damilola;Law, Wing-Cheung;Tsui, Chi-Pong
本研究采用粉末冶金与快速微波烧结相结合的方法，在常温下制备了碳纳米管填充AZ61镁合金复合材料，不需要任何二次工艺。为了确定充分利用AZ61/碳纳米管复合材料的碳纳米管的合适用量，将体积分数为1~3%的碳纳米管与AZ61合金通过机械球磨法制备了粉末混合物。优化的球磨强度可以减小碳纳米管在镁合金中的分散度，而不降低碳纳米管的结构完整性。除了加入具有机械增强和微波电感双重作用的碳纳米管外，利用石墨和碳化硅作为微波电感的协同组合，在微波炉中仅需8min即可实现微波烧结。对孔隙率在4%~6%之间的烧结样品进行了显微组织、硬度、压缩和断裂性能的表征。硬度和压缩测试结果表明，与整体样品相比，所有复合材料的这些性能都有明显的提高。当碳纳米管体积分数为3.0%时，复合材料的显微硬度最高(接近105%的增量)；当碳纳米管体积分数为1.0%时，复合材料具有最高的极限压缩屈服强度和0.2%的偏置屈服强度，其增量分别约为59%和127%。并与整体试件进行了对比，探讨了复合材料的失效机理。(C)2016爱思唯尔有限公司。保留所有权利。
In this study, a powder metallurgy processing technique combined with rapid microwave sintering was used to synthesise carbon nanotubes (CNTs) filled AZ61 magnesium alloy composites under ambient conditions, without recourse to any secondary process. In order to determine the appropriate amount of CNTs for taking full advantage of the AZ61/CNTs composite, a powder mixture of the CNTs, in varying volume fractions of 1-3%, and the AZ61 alloy was prepared through a mechanical milling process. The optimized milling intensity allowed for reducing the powder size for effective microwave absorption, and thus improved the dispersion of the CNTs in the Mg alloy matrix without reducing the structural integrity of CNTs. In addition to the incorporation of the CNTs with the dual role of mechanical reinforcement and microwave susceptor, microwave sintering was achieved in only 8 min by using a synergetic combination of graphite and silicon carbide as microwave susceptors in a microwave furnace. The sintered samples, whose porosity ranged between 4 and 6%, were characterised for microstructural, hardness, compressive and fracture properties. The results of hardness and compression tests indicated that these properties of all the composites were significantly improved compared to the monolithic samples. The highest microhardness value (similar to 105% increment) was recorded for the composite with 3.0% volume fraction of CNTs, while the composite sample with 1.0% volume fraction of CNTs had the highest ultimate compressive yield strength and 0.2% offset yield strength with approximate increments of 59% and 127%, respectively. The failure mechanisms of the composites as compared with the monolithic samples were discussed. (C) 2016 Elsevier Ltd. All rights reserved.