Sarah Boyer

High entropy alloys (HEAs) are alloys composed of five or more metallic elements in similar concentrations. HEAs have attracted substantial interest due to their exceptional mechanical properties compared to conventional alloys. Their compositions also contradict the well-established Hume-Rothery rules and can actually result in a greater degree of solid-solid solubility compared to mixtures with fewer components. To realize the full potential of this new class of alloys, there is a need to develop suitable processing and forming methods. Additive manufacturing offers significant advantages over conventional metal-forming techniques, such as the ability to fabricate complex shapes and make rapid design changes. The overall objective of this project is to adapt a solvent-based, direct-write 3D printing strategy developed by the Chow Lab for printing with inks containing a mixture of metallic oxides, polymer, and solvent. The polymer is used as a carrier and a polar volatile solvent is used to disperse the ink. The resulting structure will be annealed in a reducing environment, using techniques developed by the Chan Lab, to be transformed into a HEA sample. To achieve this, my initial work involves optimizing 3D printing inks composed of iron oxide (Fe 2 O 3 )​ nanoparticles with poly(caprolactone) (PCL) in hexafluoroisopropanol (HFIP). I am characterizing inks composed of a 7:3 volume ratio of Fe 2 O 3 to PCL with varying amounts of HFIP using parallel plate rheology to formulate an ink with a viscosity of 35 Pa-s. 1 Once the method is established, it will be used for a mixture of oxides to fabricate HEAs.

 

Sarah Boyer is a senior Materials Science and Engineering student currently attending Lehigh University for her Bachelor of Science. She conducts research with Professor Lesley Chow and Professor Helen Chan on Direct-Right 3D-printing of oxides to fabricate high entropy alloys. She is a Clare Boothe Luce Research Scholar. Other than being a student and conducting research, Sarah is also a member of the division I Rowing Team at Lehigh and has been rowing for three years after walking onto the team.