The enhanced mechanical properties and strain-hardening capability of CNT/Al composites achieved by heterogeneous micro-laminated architecture

Abstract A smart approach was adopted to fabricate a heterogeneous 1.5 wt% CNT/Al matrix possessing enhanced mechanical properties. The heterostructured-composite showed an excellent ultimate compressive strength of 372.19 MPa, which was approximately 33% and 76% higher than that of its homogeneous counterpart (279.83 MPa) and the monolithic Al (211.56 MPa), while keeping almost the same ultimate strain (40.5%) to that of the Al matrix (41.1%). It was proved that the discontinuous addition of CNTs to the matrix via several stages of low-energy milling (in the presence of PCA) followed by a high-energy dry-milling stage (without PCA) brought about a nonhomogeneous dispersion of CNTs in the matrix providing the opportunity for the development of heterogeneous microlaminated architecture, and finally enhanced the combination of strength and ductility of the resultant composite. The process would be technologically applicable for developing strong and ductile metal-matrix composites with different nanofillers.