Compression properties of 316L stainless steel E-BCT lattice structure based on SLM process

Abstract

The elliptic section body-centered tetragonal（E-BCT）lattice structure of 316L stainless steel fabricated based on selective laser melting（SLM），represents an enhanced lattice structure with improved compressive performance. By optimizing the cross-sectional shape of the struts in the traditional body-centered tetragonal（BCT）lattice，the compressive properties of the lattice structure are significantly improved. Based on the mathematical model of the E-BCT lattice structure，the theoretical force model，and the Timoshenko beam theory，a relationship model is derived between structural parameters and relative density as well as effective elastic modulus. E-BCT lattice structures with varying semi-major axis lengths of the elliptical cross-section are fabricated using the SLM process，and static compression tests and finite element simulations are conducted. The study reveals that as the semi-major axis and shape factor of the elliptical cross-section increase，the performance of the E-BCT lattice structure improves significantly compared to the BCT lattice. The maximum improvement in effective elastic modulus is 637%，with average experimental and theoretical simulation errors of 6.5% and 5.1% respectively. The yield strength shows the maximum increase of 654%，with an average experimental and simulation error of 5.4%. Additionally，the specific stiffness and specific strength exhibit maximum improvements of 308% and 321% respectively.

Keywords

• selective laser melting
• body-centered tetragonal
• elliptic section
• experiment and simulation
• compression property