Computational Materials Design of a High-Strength Copper Alloy for Replacing BeCu Alloys

The overall objective of this SBIR program is to design, develop, and qualify an environmentally-benign, Be-free replacement alloy for BeCu bearing alloy AMS 4534 that is used in sliding, load-bearing components of the Joint Strike Fighter (JSF) using QuesTek’s computational materials design technology. Due to their low inherent coefficient of sliding friction, high-strength BeCu alloys are widely used for load-bearing applications such as bushings. Cu with 1.9 wt% Be, AMS 4534, is a precipitation hardening alloy that achieves the highest strength in Cu-based alloys. However, the Federal government, through OSHA and the DHHS, has issued alerts to the potentially deadly consequences of exposure to beryllium and beryllium compounds. During the Phase I program QuesTek developed a thermodynamic database and material property models for Cu-based alloys. QuesTek designed two prototype alloys using its Materials By Design® technology. The microstructure and mechanical properties of the prototype alloys are being evaluated against design predictions. The Phase II program will develop the optimal alloy specification and demonstrate the targeted properties for a production-scale ingot.