Wednesday  |  Allegheny  |  02:50 PM–03:10 PM

#13783, Response of Additively Manufactured WE43 Magnesium Subjected to High-rate Tension

New material manufacturing processes such as Additive Manufacturing (AM) are now being applied to design scenarios involving extreme dynamic environments such as those associated with ballistic impact. Because AM often results in microstructures that differ significantly from their traditional counterparts, (especially in terms of microstructural length scale, defect population, and texture) it is critical to understand how such changes influence dynamic response. In this study, magnesium rare-earth alloy WE43 specimens produced by laser powder bed fusion (LPBF) are subjected to dynamic tension to evaluate their strength and failure response. Miniaturized tension Kolsky bars are used to load the specimens at strain rates of ~104 s-1. High speed imaging is also used to visualize the deformation and failure response at the microsecond and sub-millimeter time and length scales, respectively. Comparisons with quasistatic tests on materials processed under the same conditions are made to understand the effect of rate on the mechanical response. Our initial results show that the flow stress and ultimate tensile strengths are similar to quasistatic tests, although strong shear bands traversed the sample at high rates, unlike quasistatic tension. These differences are being confirmed with multiple tests, accompanied with evaluation of the microstructure and understanding deformation mechanisms. Additional comparisons are made with wrought WE43 to better understand the effects of the AM-induced microstructure on the high-rate mechanical response. Importantly, the miniature tests serve to benchmark dynamic test methods for AM materials, and are important for the small volume of material that is produced at the material development stage using AM technology.

Brandon Turner   New Mexico Institute of Mining and Technology
Bhaskar Majumdar   New Mexico Institute of Mining and Technology
Yongho Sohn   University of Central Florida
Jamie Kimberley   New Mexico Institute of Mining and Technology