Chapter 3 - Novel carbonaceous nanomaterial–reinforced Ti- and Al-based nanocomposites by laser additive manufacturing: laser-tailored formation of in-situ reinforcement and its contribution to performance enhancement

Abstract

Advanced carbon nanomaterials, such as carbon nanotubes (CNTs), have been incorporated into metal matrix to improve its mechanical performance. However, it is difficult for nanomaterials to disperse into the matrix uniformly due to their great differences in physical and chemical properties as related to the metal matrix. The potential chemical reaction between carbon nanomaterials and metal matrix composites is another technical challenge in the fabrication of carbon nanomaterial modified metal matrix composites. In order to acquire homogeneous dispersion of carbon nanomaterials on the alloy powder for laser powder bed fusion (LPBF) process, CNTs have been incorporated into aluminum and titanium matrix powder by a planetary ball milling. The CNTs/metal nanocomposite powder with a sound flowability was prepared by optimizing ball milling process. High-performance CNTs/Ti and CNTs/AlSi10Mg nanocomposites were fabricated by LPBF process using the optimal nanocomposite powder, and the obtainable strength, ductility, and hardness were significantly improved compared with the unreinforced materials. This work proves the feasibility to fabricate high-performance nanocomposites modified with CNTs and prepared by LPBF.