A FeCrAl-Al2O3 Composite Produced via Laser Powder Bed Fusion of a Mixed Powder for Porous Catalyst Scaffolds

Journal Article · Sun Jun 30 00:00:00 EDT 2024 · Journal of Micro and Nano Science and Engineering

DOI:https://doi.org/10.1115/1.4066114· OSTI ID:2565857

Son, Kwangtae ^[1]; Kao, Hsin-Mei ^[2]; McNeff, Patrick S. ^[3]; Yang, seongun ^[1]; Ghanadi, Nahal ^[1]; Pasebani, Somayeh ^[1]; Chang, Chin-Yao ^[4]; Paul, Brian ^[1]

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1. Oregon State University
2. OREGON STATE UNIVERSITY
3. BATTELLE (PACIFIC NW LAB)
4. Ohio State University

This study proposes a novel approach for synthesizing and etching bicontinuous FeCrAl-Al2O3 composites as a means for replacing FeCrAl foams as catalyst scaffolds in bio-driven alcohol reactors for jet-fuel production. Conventional FeCrAl foams suffer from poor availability and consequent high costs. New additive manufacturing techniques provide an opportunity to produce tailored foams in reasonable times and at acceptable costs. This research aimed to generate a porous FeCrAl structure by etching a bicontinuous FeCrAl-Al2O3 composite produced by laser powder bed fusion of amalgamated FeCrAl and Al2O3 powders. The composite powder for laser powder bed fusion is created by ball-milling FeCrAl and Al2O3 powders. This research focuses on achieving a bi-continuous FeCrAl-Al2O3 structure, essential for the selective removal of the ceramic phase. The influence of laser processing parameters on the microstructure was examined across a range of laser powers (60-120 W) and scan speeds (100-400 mm/s), showing that higher powers and speeds produce finer metal struts. A bi-continuous microstructure was consistently obtained, marking a key achievement. The Al2O3 removal process involved a two-step etching method using hydrochloric and phosphoric acids, tested across various etching times. The alumina phase was reduced from 36 vol% to 17 vol% (corresponding to an increase in porosity from 24 vol% to 43 vol%), showing the potential for use as a porous catalyst scaffold. This research demonstrates the potential for using additive manufacturing to produce porous FeCrAl structures capable of replacing hard-to-source FeCrAl foams.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 2565857
• Report Number(s): PNNL-SA-205275
• Journal Information: Journal of Micro and Nano Science and Engineering, Journal Name: Journal of Micro and Nano Science and Engineering Journal Issue: 2 Vol. 12
• Country of Publication: United States
• Language: English