Date of Award

3-2023

Document Type

Thesis

Degree Name

Master of Science

Department

Department of Engineering Physics

First Advisor

Larry W. Burggraf, PhD

Abstract

The structural performance of additively manufactured Mo printed by LPBF can be significantly improved by nanoparticle alloying. Previous AFIT studies of SiC nanoparticle addition conducted by Ellsworth (2022) et al. demonstrated increased powder consolidation, leading to reduced porosity, increased microhardness, and a shift in atomic defect concentrations. The addition of defected SiC particles is proposed to reduce in situ oxidation by acting as a sacrificial oxidizing agent and contributing to the formation of Mo disilicide secondary phases. This study investigated the relationship between laser powder bed fusion Mo microscale and nanoscale properties with varying SiC particle size while maintaining a mass fraction of 0.01 with respect to Mo. It was found that hardness increased by 13 %, porosity decreased by 46 %, printed surface roughness decreased by 32 %, and sheet resistance decreased by 6 % on average with the addition of nanoparticle SiC across varying LED prints. These initial laser powder bed fusion studies have shown promise in the universal application of nanoparticles and SiC additions for enhanced LPBF printing of refractory metals.

AFIT Designator

AFIT-ENP-MS-23-M-289

Comments

A 12-month embargo was observed.

Approved for public release. PA case number on file.

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