Session: 03-10-02: Laser-Based Advanced Manufacturing and Materials Processing

Paper Number: 147357

147357 - Additive Manufacturing of Lattice Structures for Catalyst Applications 

Open-pore lattice structures, characterized by interconnected struts, present porous configurations that offer lightweight yet high-strength designs and are extensively employed across various industries, such as the energy sector and catalytic applications. Lattice structures used as catalyst supports offer advantages in terms of surface area, mass transport, structural integrity, and design flexibility, making them a preferred choice in many catalytic applications, including jet fuel production.

Additive manufacturing, particularly Laser Powder Bed Fusion (LPBF), stands out as a superior method for fabricating lattice structures compared to conventional methods, as it allows for precise control over the deposition of powder material, enabling the creation of volumetrically complex lattice geometries layer by layer. In this work, Inconel 718, recognized for its exceptional strength, corrosion resistance, and high-temperature performance, has been selected to fabricate lattice structures using LPBF by considering the target application temperature of > 400 °C. This research aims to design open pore lattice structures with high porosity (i.e., porosity > 60%), specific surface area higher than 3 mm²/mm³, and pore size in the range of 500 um to 1000 um. These porous structures are intended to be used as catalyst supports, replacing conventionally made foams for cost reduction.

However, fabricating metallic lattice structures using LPBF poses challenges compared to solid structure fabrication due to the inherent delicacy of lattice structures. This research analyzes the variations in the LPBF printability windows of Inconel 718 solid and open pore structures, plotted based on the density of solid blocks and lattice structures with minimal geometrical deviation from the 3D model. Through experimental analysis, it is demonstrated that applying different processing parameters, i.e., laser power ranging from 50 W to 220 W and scanning speed ranging from 100 mm/s to 1200 mm/s, significantly influence the geometrical aspects of the printed lattice structures. Moreover, a significant geometrical distinction has been observed in the top and side surfaces of the lattice structures, which is attributed to the staircase effect of the LPBF process. In this work, the impact of processing parameters on specific surface area (mm²/mm³), porosity, pore size, and strut size of lattice structures have been investigated and characterized using X-ray micro-computed tomography, microscopic imaging methods such as optical microscope and scanning electron microscopy, and Archimedes density measurements using a high-resolution four-digit scale. Additionally, the effect of constant volumetric energy density with different processing combinations on geometrical accuracy is studied, revealing that laser power has a more pronounced influence on geometrical accuracy compared to scanning speed. Finally, the mechanical properties of printed lattice structure sets are assessed using a universal tester to investigate the effect of geometrical aspects of the lattice structure on its mechanical performance.

Presenting Author: Nahal Ghanadi Oregon State University

Presenting Author Biography: Nahal Ghanadi is a graduate research assistant in advanced manufacturing at the School of Mechanical Engineering at Oregon State University. She completed her master's studies in mechanical engineering at Sapienza University of Rome. Her research primarily focuses on metal additive manufacturing, and she is currently working on projects to understand the joining mechanisms in dissimilar metal additive manufacturing and the designing of open-pore structures for catalytic applications.

Authors:

Nahal Ghanadi Oregon State University
Kwangtae Son Oregon State University
Brian Paul Oregon State Univeristy
Somayeh Pasebani Oregon State University