Investigating multi-material Ti-42Nb lattice structures fabricated via laser powder bed fusion using a genetic algorithm to optimize Ti-5553 reinforcement band position

Abstract

Laser Powder Bed Fusion (LPBF) technologies enable the production of cellular lattice structures (CLSs), known for their promising applications in stress-bearing environments due to their superior performance under load conditions with minimal mass. This study explores the enhancement of multi-material lattice structures via additive manufacturing, leveraging Ti-42Nb and Ti-5553 alloys to refine mechanical properties through optimized reinforcement layering. Adopting a dual-alloy strategy, it assesses the interplay between Ti-42Nb and the structurally superior Ti-5553, aiming to boost the mechanical performance of the components. Optimization of reinforcement placement was achieved using a genetic algorithm coupled with Finite Element Method and reinforcement band thickness was adjusted to maintain integrity post-melt pool processing. A heat treatment at 500 °C was identified as critical for increasing hardness and elastic modulus in the reinforcement phase. Compression testing demonstrated the effectiveness of this reinforcement strategy, showing improvements up to 50 % in load-bearing capacity and mechanical tenacity with the addition of a reinforcement band notably altering deformation mechanisms of multi-material structure. These findings affirm that lattice structures and multi-material parts manufactured through additive processes offer promising prospects for applications in industries requiring advanced material performance.