Bioinspired composites reinforced with ordered steel fibers produced via a magnetically assisted 3D printing process

Abstract

Biological materials generally have better properties than engineered materials due to their intricate architecture, e.g., high strength-to-weight ratio, stiffness, toughness and adaptability. It has proven difficult to synthesize materials with biomimetic architecture. Recently, 3D printing techniques show great promise in bioinspired structural materials. In this paper, we propose an approach to fabricate composite materials with aligned steel fibers using a self-made 3D printer and characterized the mechanical properties of the prepared materials. To do so, we developed a DLP-based 3D printing process that can align short steel fibers in the resin matrix via magnetic assembly during the printing process. Using the developed process and raw materials, samples with ordered fibers were prepared. The mechanical properties of the printed materials, including the strength and friction, as well as morphology, were characterized. The results show that magnetically assisted scraper shear-induced 3D printing can realize the ordered arrangement of fibers. The tensile and compressive strength consistent with the direction of aligned fibers are higher than that of other directions. The friction performance perpendicular to the direction of aligned fibers is better than that of other directions. The mechanical and frictional properties of the composite contenting 5% fibers are better than that of 10% or 15%. This study provides a basis for the manufacture of biomimetic materials. A magnet-assisted assembly 3D print technology is developed to produce steel fiber-resin composites with ordered architecture by programming the traveling paths of a magnet. To demonstrate the feasibility of the proposed method, a helicoidal ladder structure with ordered reinforced fibers is printed. Finally, the mechanical properties of printed composite materials with various patterns of aligned fibers are characterized.