Ultralight, Strong Three Dimensional SiC Structures

Abstract

Ultralight and strong three-dimensional (3D) silicon carbide (SiC) structures have been generated by the carbothermal reduction of SiO with a graphene foam (GF). The resulting SiC foams have an average height of 2 mm, and density ranging between 9-17 mg cm-3. They are the lightest reported SiC structures. They consist of hollow struts made from ultrathin SiC flakes, and long 1D SiC nanowires growing from the trusses, edges and defect sites between layers. AFM results revealed an average flake thickness of 2-3 nm and lateral size of 2 µm. In-situ compression tests in the scanning electron microscope (SEM) have shown that, compared with most of the existing lightweight foams, the present 3D SiC exhibited superior compression strengths and significant recovery after compression strains of about 70%.