Laser texturing of metal interface for multi-materials parts fabricated by directed energy deposition

• Main Author: Ong, William Wei Min
• Other Authors: Zhou Wei
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Additive manufacturing; Multimaterial; Shear strength; Finite element analysis
• Online Access: https://hdl.handle.net/10356/181872
• Institution: Nanyang Technological University

This study investigates the application of Directed Energy Deposition (DED) for creating textured metal surfaces to enhance interfacial strength in multi-material assemblies. Three different surface textures were explored in this study. The results demonstrate that the specific features could achieve much higher shear strength, attributed to its superior geometric features and optimized interfacial bonding. Finite element analysis confirmed these findings, showing strong alignment between predicted and experimental stress distribution patterns. Microstructural analysis revealed columnar grain formation within the DED-fabricated features, consistent with observations from rapid cooling studies during DED. Microhardness tests indicated that DED components exhibit greater hardness compared to rolled substrates, supporting the relationship between grain refinement and hardness in additive manufacturing. However, defects such as porosity and lack of fusion were noted in some cases, suggesting that intricate geometries may require precise parameter tuning to ensure complete bonding. These results align with existing literature on additive manufacturing, indicating that while DED shows promise for robust multi-material bonding, optimal outcomes necessitate careful adjustment of parameters such as laser power, scan speed, and material feed rate. Future research should explore alternative texturing designs and assess joint performance under varied operational conditions to evaluate long-term durability. Overall, this research reinforces the viability of DED for multi-material bonding applications and contributes valuable insights to advance additive manufacturing techniques for creating reliable, high-strength multi-material.