Laser powder bed fusion based pure copper lattice fabrication and characterization
The additive manufacturing is changing the industry with freedom of design, fast prototyping, and waste minimization. For metals, the laser powder bed fusion (LPBF) in which raw powder material is melted by focused laser beam and solidification, is one of the promising techniques among a variety of additive manufacturing processes. Through intensive studies, it has been demonstrated that various metals and alloys with dense microstructure can be fabricated through LPBF. Current research is focused not only on the microstructure of the LPBFed metal but also on the complex geometries that can give functionality to the material.
Copper which has become an essential component in engineering applications with its high electrical and thermal conductivity, however, is a hard to fabricate material via the LPBF method. This is due to the high laser reflectivity of copper, which prevents the copper powder from absorbing laser energy from the conventional red laser efficiently. The research on the LPBFed copper, therefore, is still focused on optimizing the process parameters for obtaining fully-dense microstructure.
In this project, we fabricate the copper with a new green laser beam source. Under the green laser, it is expected that the copper powder will be able to absorb enough energy for melting properly and a dense microstructure can be achieved. Specifically, we will address the open questions on the process parameter-microstructure-mechanical property relationships in LPBFed copper using 3-dimensional lattice architectures, under both quasi-static and dynamic loading conditions.