Enhanced mechanical properties of CNT/Al composite through tailoring grain interior/grain boundary affected zones

Abstract

Abstract The relationship between different ball milling (BM) conditions and mechanical properties of CNT/Al composites was studied through tailoring grain interior/grain boundary affected zone (GI/GBAZ). The ultrafine-grained (UFGed) architectures of the CNT/Al composites made from flake powders with the same thickness under different BM conditions, introduce different strain rates and vary dislocation density. The results showed that the grain size of CNT/Al composite were significantly influenced by milling conditions, which caused obvious variations in mechanical properties. The enhancing in tensile properties of CNT/Al composite mostly caused by grain refinement, dislocation strengthening, and back stress hardening, which last two terms are closely linked to GBAZ thickness. The simulated results agreed well with experimental results, confirming a strain rate dependency of GBAZ thickness. This work strengthened the understanding of ball milling process on the microstructure and mechanical properties of metal matrix composites.