Preparation and Microstructure of Multi-Wall Carbon Nanotubes-Toughened Al₂O₃ Composite

With multi-wall carbon nanotubes (MWNTs) as reinforcement, a 12 vol% MWNTs/alumina (Al₂O₃) ceramic composite was obtained by hot pressing. A fracture toughness of 5.55±0.26 MPα-m,1.8 times that of pure Al₂O₃ ceramics, was achieved. Experimental results showed that the enveloping of carbon nanotubes (CNTs) with sodium dodecyl sulfate (SDS) is effective in changing the hydrophobicity of CNTs to hydrophili-city and improving the dispersion of CNTs in aqueous solution. Enveloped with SDS, CNTs can be homogeneously mixed with Al₂O₃ at a microscopic level by heterocoagulation. This mixing method can obviously improve the chemical compatibility be-tween CNTs and Al₂O₃, which is important for enhancement of interfacial strength between them.