Graphene-coated tungsten nanowires deliver unprecedented modulus and strength

Abstract

Tungsten (W) nanowires have a wide range of chemical, electronic, and mechanical applications. However, the modulus and strength of traditional W nanowires are quite low, and how to improve their mechanical performance remains a challenge. Here, we describe a novel graphene-coated W nanowires that demonstrate a Young’s modulus of 885 GPa (twice that of W) and a fracture strength of up to 24.7 GPa (66% of the ideal strength). Both the Young’s modulus and the fracture strength show a strong size effect, resulting from the graphene-nanowire core–shell structure. Keywords: W nanowires; graphene; Young's modulus; fracture strength; size effect