Achieving Remarkable Specific Mechanical Strength and Energy Absorption Capacity in SiC Nanowire Networks through Graded Structural Design.

Abstract

Lightweight porous ceramics with a unique combination of superior mechanical strength and damage tolerance are in significant demand in many fields such as energy absorption, aerospace vehicles, and chemical engineering; however, it is difficult to meet these mechanical requirements with conventional porous ceramics. Here, we report a graded structure design strategy to fabricate porous ceramic nanowire networks that simultaneously possess excellent mechanical strength and energy absorption capacity. Our optimized graded nanowire networks show a compressive strength of up to 35.6 MPa at a low density of 540 mg·cm^-3, giving rise to a high specific compressive strength of 65.7 kN·m·kg^-1 and a high energy absorption capacity of 17.1 kJ·kg^-1, owing to a homogeneous distribution of stress upon loading. These values are top performance compared to other porous ceramics, giving our materials significant potential in various engineering fields.