Optimization design and experimental investigation of gradient TPMS lattice structures for additive manufacturing of silicon nitride ceramics

Purpose This paper aims to address the insufficient utilization of mechanical properties in traditional homogeneous silicon nitride lattice structures under three-point bending conditions. A set of design and preparation processes for gradient lattice structures of silicon nitride ceramics is proposed, along with the parameters of digital light processing technology. Design/methodology/approach A topology optimization method is integrated with triply periodic minimal surface (TPMS) lattice structures to achieve the optimized design. Three-dimensional models of silicon nitride ceramic gradient lattice structures are designed and fabricated via a gradient-based optimization algorithm and digital light processing technology with customized photocuring parameters. Findings The gradient lattice structures of silicon nitride ceramics significantly outperform traditional homogeneous lattices, exhibiting enhanced flexural strength, stiffness, flexural modulus and specific stiffness under bending conditions. Research limitations/implications This study mainly focuses on the bending test condition. Future work will be extended to complex multi-load conditions. Originality/value This work presents an optimization procedure for gradient TPMS lattice structures of silicon nitride ceramics, offering a new modeling design method for generating STL files of additive manufacturing. It demonstrates the feasibility and effectiveness of gradient lattice designs through optimization and experimental validation.