An aluminum-based composite material with multi-walled carbon nanotubes: fabrication, structure and properties

Background. Increased demands for strengthened conventional materials, capable of satisfying needs of technological advances, make the study and fabrication of composites, reinforced with dispersed particles or fibers, topical for domestic and foreign scientists. Addition of multi-walled carbon nanotubes (MWCNT) as a reinforcing component in a matrix metal allows obtaining a material with high performance characteristics. The purpose of the work is to study the effect of MWCNT on the microstructure and mechanical properties of pure aluminum. Materials and methods. The aluminum powder PAD-6* (produced by Ltd. "VALCOM-PM") with 99.9% purity and pristine MWCNTs having 2% of amorphous carbon and graphite, produced by the MOCVD method (Metal Organic Chemical Vapor Deposition) and functionalized via acid treatment by the H${_2}$SO${_4}$/HNO${_3}$ mixture, were used in this study. Compacting of mixed materials was performed by spark plasma sintering at 600${}$С under 50 MPa of applied stress for 20 min in a vacuum. The following methods were used to study the composites: electron microscopy, micro-hardness Vickers test, static tension test. Results. The authors studied the effect of FMWCNT on the microstructure and mechanical properties of composites. It is shown that functionalization allows homogeneous dispersing of MWCNTs in the Al powder. The maximal increase in micro-hardness and tensile strength has been registered at 0.1 wt.%.