BS in Materials Engineering
Materials Engineering Department
Microcracking has caused premature failure and reduction in properties in additively manufactured (AM) Hastelloy X. The purpose of this research is to meet or exceed the mechanical properties of wrought Hastelloy X by modifying the composition and build direction of Hastelloy X manufactured using Direct Metal Deposition (DMD). Tensile testing, scanning electron microscopy (SEM), and metallography were performed on the samples. ANOVA was used to analyze the dependence that the properties had on build direction and composition. The nominal composition wrought samples had a yield strength of 310.1 MPa and a 60.79% Elongation. Alloy P60-X18 in a horizontal build had the highest yield strength of 363.67 MPa because it is the most solid solution strengthened alloy. Vertically-built P60-X18 had the highest ductility of 78.62%. Altering the composition had a greater effect on yield strength than changing the build direction. Overall, changing composition resulted in a higher yield strength while maintaining high ductility; therefore, the additively manufactured parts would be suitable for use in an application. Further modification of the solid solution strengthening elements could be performed to precisely match or exceed the wrought Hastelloy X properties. Additionally, corrosion, high-temperature, and application-specific properties should be verified in the new alloys.