Additive Manufacturing of Zirconium Carbide in Complex Geometries for Nuclear Thermal Propulsion
Faculty Mentor Information
Allyssa Bateman (Mentor), Boise State University; and Dr. Brian Jaques (Mentor), Boise State University
Abstract
Uranium carbide (UC) is a potential fuel for space nuclear propulsion. Additive manufacturing (AM) of UC fuels would allow researchers to manufacture the complex geometries required for space propulsion reactors, while reducing manufacturing waste as compared to traditional subtractive methods;however, developing new processes with radioactive materials can be costly and time-consuming. Accordingly, surrogate materials, such as zirconium carbide (ZrC), provide a simplified pathway for method development. ZrC is an attractive material for use in nuclear environments due to its high temperature stability, radiation tolerance, low neutron absorption cross section, and impressive thermal conductivity. ZrC can also act as a surrogate for UC. In this work, ZrC was used as a surrogate for UC to develop a process to additively manufacture complex geometries of ceramic materials. ZrC powder was mixed with polyethyleneimine (PEI) and water to create a ZrC ink suitable for printing via direct ink writing. After printing, parts underwent a bake-off step to slowly remove the PEI. Then samples were heated to 2100 ℃ in order to reach a target density of 80%. Sample characterization included density, microstructure, and phase purity to verify that this process successfully produced dense, phase-pure ZrC in complex geometries.
Additive Manufacturing of Zirconium Carbide in Complex Geometries for Nuclear Thermal Propulsion
Uranium carbide (UC) is a potential fuel for space nuclear propulsion. Additive manufacturing (AM) of UC fuels would allow researchers to manufacture the complex geometries required for space propulsion reactors, while reducing manufacturing waste as compared to traditional subtractive methods;however, developing new processes with radioactive materials can be costly and time-consuming. Accordingly, surrogate materials, such as zirconium carbide (ZrC), provide a simplified pathway for method development. ZrC is an attractive material for use in nuclear environments due to its high temperature stability, radiation tolerance, low neutron absorption cross section, and impressive thermal conductivity. ZrC can also act as a surrogate for UC. In this work, ZrC was used as a surrogate for UC to develop a process to additively manufacture complex geometries of ceramic materials. ZrC powder was mixed with polyethyleneimine (PEI) and water to create a ZrC ink suitable for printing via direct ink writing. After printing, parts underwent a bake-off step to slowly remove the PEI. Then samples were heated to 2100 ℃ in order to reach a target density of 80%. Sample characterization included density, microstructure, and phase purity to verify that this process successfully produced dense, phase-pure ZrC in complex geometries.