Processing-Property Relationships in Yttria-Steel Matrix Nanocomposites Fabricated via TIG Welding-Based Directed Energy Deposition
Faculty Mentor Information
Dr. Michael Maughan, University of Idaho
Presentation Date
7-15-2026
Abstract
Metals reinforced with ceramic nanoparticles exhibit superior mechanical properties compared to the pure material due to dispersion hardening. However, nanoparticles agglomeration, which occurs during casting, represents a significant challenge to these metal matrix nanoparticle composite (MMNC) materials. Critically, agglomerations in the metal matrix create stress concentrations which may cause the material to crack, fatigue, and fail more easily. Therefore, the minimization of nanoparticle agglomeration in the matrix requires a different manufacturing process to optimize the strength of MMNCs. As an alternative process to synthesize MMNCs, the goal is to use directed energy deposition additive manufacturing (DED AM) to introduce yttria nanoparticles within a steel matrix. To do this, heat input, deposition pathing, and nanoparticle delivery methods were evaluated using gas tungsten arc welding to optimize the dispersion of nanoparticles throughout the matrix during material synthesis. Scanning electron microscopy, energy dispersive spectroscopy, and Vickers hardness testing were used to assess nanoparticle dispersion and mechanical properties of the DED AM MMNCs, respectively. MMNCs were synthesized with hardness values 40% greater than the pure steel baseline. Gas tungsten arc welding shows promise as a suitable fabrication method of MMNCs, and this work establishes processing-property relationships that can guide future study into parameter optimization.
Processing-Property Relationships in Yttria-Steel Matrix Nanocomposites Fabricated via TIG Welding-Based Directed Energy Deposition
Metals reinforced with ceramic nanoparticles exhibit superior mechanical properties compared to the pure material due to dispersion hardening. However, nanoparticles agglomeration, which occurs during casting, represents a significant challenge to these metal matrix nanoparticle composite (MMNC) materials. Critically, agglomerations in the metal matrix create stress concentrations which may cause the material to crack, fatigue, and fail more easily. Therefore, the minimization of nanoparticle agglomeration in the matrix requires a different manufacturing process to optimize the strength of MMNCs. As an alternative process to synthesize MMNCs, the goal is to use directed energy deposition additive manufacturing (DED AM) to introduce yttria nanoparticles within a steel matrix. To do this, heat input, deposition pathing, and nanoparticle delivery methods were evaluated using gas tungsten arc welding to optimize the dispersion of nanoparticles throughout the matrix during material synthesis. Scanning electron microscopy, energy dispersive spectroscopy, and Vickers hardness testing were used to assess nanoparticle dispersion and mechanical properties of the DED AM MMNCs, respectively. MMNCs were synthesized with hardness values 40% greater than the pure steel baseline. Gas tungsten arc welding shows promise as a suitable fabrication method of MMNCs, and this work establishes processing-property relationships that can guide future study into parameter optimization.