A high-temperature nanostructured Cu-Ta-Li alloy with complexion-stabilized precipitates.

Hornbuckle, B C; Smeltzer, J A; Sharma, S; Nagar, S; Marvel, C J; Cantwell, P R; Harmer, M P; Solanki, K et al. · Science · 2025

basic_science · Level V

Where this comes from

Abstract

We present a bulk nanocrystalline copper alloy that can operate at near-melting temperatures with minimal coarsening and creep deformation. The thermal stability of the Cu-3Ta-0.5Li atomic % (at %) alloy is attributed to coherent, ordered L1<sub>2</sub> Cu<sub>3</sub>Li precipitates surrounded by a tantalum-rich atomic bilayer phase boundary complexion. Adding 0.5 at % lithium to the immiscible Cu-Ta system changes the morphology of the nanoscale precipitates from spherical to cuboidal while simultaneously tailoring the phase boundary. The resultant complexion-stabilized nanoscale precipitates provide excellent thermal stability, strength, and creep resistance. The underlying alloy design principles may guide the development of next-generation copper alloys for high-temperature applications such as heat exchangers.