Tensile and compressive response of tungsten g-TPMS lattice structures

Abstract

The present study explores the mechanical behavior of tungsten (W) gyroid Triply Periodic Minimal Surface (g-TPMS) lattice structures through atomistic simulations, focusing on models with varying lattice thickness or simply volume fractions. It examines the mechanical behavior of these structures under both tensile and compressive loads. The research demonstrates that strength and ductility in g-TPMS can be adjusted through design, showcasing unique behaviors not found in bulk materials. A relationship between elastic modulus and volume fraction is established, providing coefficients for multi-scale modeling and simulation. W g-TPMS structures with higher volume fractions exhibit increased tensile strength, peaking at approximately 7.6 GPa for structures with a 59 % volume fraction. The study further reveals that temperature variations significantly affect the mechanical response, with tensile strength decreasing from 4.5 GPa at 300 K to below 2.0 GPa at 3000 K. Additionally, helium embrittlement is shown to markedly reduce tensile strength, with a 15 % helium interstitial concentration leading to a 60 % reduction in peak stress. These findings emphasize the potential of tailored W g-TPMS materials for advanced applications like nuclear fusion reactors.