Laser powder bed fusion of 316L/CuCrZr bimetal component

• Main Author: Li,Guanchun
• Other Authors: Zhou Wei
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/180816
• Institution: Nanyang Technological University

This study explores the fabrication and properties of a 316L/CuCrZr bimetal structure using Laser Powder Bed Fusion (LPBF). The microstructure analysis revealed cracks in the 316L-rich zone due to the immiscibility of Cu and Fe, causing hot cracks during solidification. A hot crack (or solidification crack) is a type of defect that occurs during the final stages of solidification in welding or metal casting processes. It forms when the material is under thermal stress while transitioning from a molten to a solid state, particularly in areas where shrinkage is constrained. Mechanical testing showed microhardness values of 224 HV for the 316L-rich zone, 147 HV for the immiscible zone, and 102 HV for the CuCrZr side, with tensile strengths indicating a yield strength of 203.0 MPa and an ultimate tensile strength of 287.5 MPa. The study highlights LPBF's potential for fabricating bimetal structures but notes challenges with interface cracks. Future research should focus on optimizing parameters and exploring interlayer solutions.