Copper-based alloys for structural high-heat-flux applications: a review of development, properties, and performance of Cu-rich Cu-Cr-Nb alloys

This review examines the development and current state of Cu-rich Cu-Cr-Nb alloys commonly referred to as GRCop or Glenn Research copper alloys with emphasis on Cu-8Cr-4Nb (at%), or GRCop-84, and Cu-4Cr-2Nb, or GRCop-42. Recent additive manufacturing efforts have increased interest in GRCop alloys, and full-scale hardware has been fabricated using AM techniques and practical hot-fire tests have been conducted, but structure-property relationships are still under development. The development, processing, and current microstructure-property relationships of GRCop alloys are reviewed along with comparisons to similar high-heat-flux Cu alloys including NARloy-Z, GlidCop Al-15, AMZIRC, Cu-1Cr-0.1Zr, and Cu-0.9Cr. The review concludes with an assessment of future prospects for GRCop alloys and overview of advantages provided by additive manufacturing.