Fundamental Understanding of Microstructure-Micromechanics Relationships of Additive Manufactured Components and Dissimilar Welds through Neutron Scattering

GRCop-84 is a precipitation strengthened alloy composed of Cu-8 Cr-4 Nb at% with Cr2Nb precipitates that provide dispersion and precipitation strengthening characteristics and limited solubility in the Cu matrix. The particle role of Cr2Nb (C15 Laves) is unusual only contributing 1/3 of strengthening at high temperatures while the matrix provides the remainder. The particles mechanically and thermally stabilize the matrix retaining Cu purity and preventing coarsening and loss of strength. At high temperatures (50-85% TmCu), GRCop-84 provides the best thermal and mechanical properties of available alloys.

GRCop-84 is currently in development for reusable launch vehicles including the Space Launch System (SLS) with a focus on fabrication with additive manufacturing (AM) techniques. GRCop-84 is an optimal material for consolidating with AM. The base material is costly, the production times are long, and more geometry control can considerably improve cooling efficiency. Development of AM GRCop-84 with selective laser melting (SLM) has rapidly progressed due to ease of printing and limited operator adjustment between builds, but the necessary knowledge-base of thermal history and stress state during builds is still under development.

Industry Sponsor: NASA

Faculty: Claudia Rawn and Hahn Choo

Graduate Student: Robert Minneci

Industry Contact: Jeffery Sowards