Planting carbon nanotubes within Ti-6Al-4V to make high-quality composite powders for 3D printing high-performance Ti-6Al-4V matrix composites

We developed a novel process of planting carbon nanotubes (CNTs) within spherical Ti-6Al-4V powder to fabricate a CNTs/Ti-6Al-4V composite powder. The new powder addressed the issues of spherical morphology maintaining and homogenous dispersion of CNTs, and thereby exhibited good printability. After printing, a relative density of 99.9% was obtained. Microstructurally, some CNTs were retained, while the remaining formed TiC nanoparticles and nanoplatelets via interfacial reaction and dissolution-precipitation mechanisms, respectively. The printed composites had tensile yield strength of 1162 MPa and elongation of 3.2% due to synergistic effect of bridge enhancement of TiC nanoplatelets and load transfer from matrix to CNTs. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.