Failure behavior of 70/30 brass lattice structure with a proposed cell topology produced by rapid investment casting

Abstract

Lattice structures are unique architectural configurations with repeated unit cells and significant void spaces, offering exceptional specific strength, stiffness, and energy absorption capacity. These properties make them ideal for lightweight structures and mechanical dampers. Rapid investment casting, a blend of investment casting and 3D printing, emerges as a promising method for metal lattice structure production. It outperforms typical metal additive manufacturing, yielding products with fewer defects. A proposed cell topology has been introduced, striking an optimal balance between printability, castability, tensile strength, and shear strength. To explore its performance under compressive loading, 70/30 brass lattice structures with two varying heights were fabricated using rapid investment casting and evaluated. Shorter samples displayed uniform expansion within each cell row, while taller ones experienced abrupt shear fractures, resulting in lower absorbed energy. Detailed microstructure observations and additional mechanical properties were obtained, enhancing the understanding of failure behavior. In conclusion, rapid investment casting combined with the proposed cell topology opens exciting possibilities for manufacturing high-performance lattice structures with improved mechanical characteristics.