Be-free, High-Strength Cuprium® Cu Alloy
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Materials by Design® Background QuesTek computationally designed and developed a Be-free, Cu-based, high-strength Cuprium® alloy using its Materials by Design® technology under U.S. Navy SBIR Phase II funding to be a nontoxic substitute for BeCu and also stronger than existing Be-free Cu-based alloys. This Cuprium alloy has been produced both as centrifugal castings and as VIM+VAR billets. The properties presented below are from heat-treated centrifugal castings without any cold working and are representative of very large size castings (achieving >130 ksi YS on 15 inch diameter centrifugal castings). Hence, they are not subject to size limitation is sues experienced by Cu-Ni-Sn alloys. Thus, in the cast state this Cuprium alloy can b e used for large-scale components where forgings are not possible. Mechanical Properties

Thermal Conductivity The thermal conductivity of this Cuprium alloy was measured relative to BeCu. The conductivity of this fully heat treated Cuprium alloy is ~0.25W/cm-K at room temperature, which is lower than BeCu but comparable to Cu-Ni-Sn alloys. The thermal conductivity increases with temperature due to rising thermal diffusivity until ~600°C, after which a drop is observed because the strengthening precipitates start dissolving, thereby increasing the solute content of the matrix. Electrical Behavior Electrical properties were evaluated in the fully heat treated state and at...