Analysis of interface shape and mechanical properties of 3D printed 316L-CuCrZr

• Main Author: Tan, Jaryl Jun Heng
• Other Authors: Xiao Zhongmin
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering; Additive manufacturing
• Online Access: https://hdl.handle.net/10356/176173
• Institution: Nanyang Technological University

Additive manufacturing has caused a new era in manufacturing due to the production of components with complex geometries and hybrid materials with superior properties. This has sparked a surge in interest in additive manufacturing that combines different metal alloys with superior properties. In particular, the exploration into the selective laser melting of 316L and CuCrZr within the context of multi-material additive manufacturing remains relatively uncharted. By systematically manipulating printing parameters such as laser power, exposure time, point distance and scanning speed, the research investigates the effect of these critical printing parameters on the bond formation between 316L and CuCrZr, with a primary focus on the interface morphology. This project also correlates the observed interface characteristics with the mechanical properties of the samples to determine a relationship between Volumetric Energy Density, E_v and the resulting interfacial defects and characteristics. Experimental results indicate that an optimal range of 30 J/mm3 < E_v < 80 J/mm3 can minimise defects, such as incomplete fusion holes and cracking while maintaining good interface characteristics and mechanical properties. E_v ≥ 80 J/mm3 can be utilised but exposure time should be maximised while minimising scanning velocity to reduce the formation of defects. Higher laser power can also lead to more substrate penetration and thus better interface bonding. Using the remelting strategy of the first layer 3 times can help to encourage better diffusion of metals but a laser power of 200W should be avoided as results show poor interface bonding, interface delamination and interface fracture during tensile tests. The findings articulate the importance of fine-tuning SLM process parameters to achieve a close to defect-free interface, yielding a hybrid metal with significantly enhanced mechanical properties over a CuCrZr substrate.