Characterization of the electrical properties of copper parts produced by Laser Powder Bed Fusion

Abstract

LASER – Powder Bed Fusion technology is an Additive Manufacturing (AM) process consisting of the production of components with complex geometries, especially for the biomedical, automotive, and aerospace fields. In L-PBF, a LASER beam selectively melts regions of a powder bed, previously spread over already processed powder layers, forming an iterative process.Copper presents greater difficulties in being additively manufactured with L-PBF than other alloys such as stainless steel and Inconel, due to its high reflectivity at wavelengths of the common fiber lasers. AM Pure Copper has only recently achieved the capabilities to reach values adequate for industrial electrical applications for properties such as relative density, mechanical resistance, and electrical conductivity. This is possible thanks to the implementation of strategies such as high-power laser systems.This thesis work is an experimental study on the electrical conductivity of AM Pure copper, produced with L-PBF with high power laser (nominal 1kW). In the first phase, AM Pure Copper characterized and its validity as a material for electrical applications in the E-Mobility sector is verified under mechanical and electrical aspects.In the second experimental phase, influences of process parameters are studied, focusing on Volumetric Energy Density (VED), and subsequently optimal sets of parameters both in terms of electrical conductivity and productivity are searched.This master thesis project was part of EIT-Manufacturing MSc Double Degree “Additive Manufacturing For Full Flexibility”, completed at Politecnico di Milano and Technische Universität Wien. Addtoshape Srl offered the opportunity develop a thesis project in a work environment in the manufacturing sector, regarding pure copper L-PBF.