The use of flake powder metallurgy to produce carbon nanotube (CNT)/aluminum composites with a homogenous CNT distribution

A strategy called flake powder metallurgy (flake PM) was used to achieve a uniform distribution of carbon nanotubes (CNTs) in CNT/Al composites and thus realize the potential of CNTs as a reinforcement. It consists of the addressing of the incompatibilities of Al powders with CNTs, uniform adsorption of CNTs onto the Al nanoflake surface by slurry blending and consolidation of as-prepared CNT/Al composite powders by hot extrusion. By changing spherical Al powders to nanoflakes and surface modifying them with a polyvinyl alcohol hydrosol, flake PM achieved high compatibilities of Al powders with CNTs, in terms of both surface properties and geometries. Thus, it essentially exploits the fact that a homogeneous and individual distribution of CNTs in Al powders can be achieved simply by direct slurry blending. Moreover, the structural integrity of the CNTs was well maintained in the final composites since CNTs were protected from high energy physics force such as ballmilling. As a consequence, a strong and ductile CNT/Al composite with tensile strength of 435 MPa and plasticity of 6% was fabricated, which greatly surpasses values for materials fabricated by conventional methods. (C) 2012 Elsevier Ltd. All rights reserved.