High Strength Copper Alloys for Rocket Engine Applications
A. B. Pandey, Pratt & Whitney Rocketdyne, West Palm Beach, FL
There has been increasing interest to develop high strength copper alloys to improve performance of rocket engines. Typically, copper alloys are used for thrust chamber applications in rocket engines for efficient heat transfer capability. Copper alloys are currently limited in their ambient and high temperature strengths. The purpose of this presentation is to provide a comparison of properties for commercially available high strength copper alloys with reference to the requirements of rocket engines. The data are analyzed to provide insight into the strengthening mechanisms for these copper alloys. Most copper alloys derive strengthening from precipitation hardening and dispersion hardening. The basis for dispersion strengthening materials is the individual dislocation-particle interaction mechanism. Narloy-Z is currently used for thrust chamber application that is based on precipitation strengthening mechanism. Cu-Cr alloy (also known as Anaconda) is another precipitation strengthening material that is considered for comparison. Two materials based on dispersion strengthening mechanisms are considered: (a) GRCop-84 and (b) GlidCop. GRCop-84 is a NASA material that contains Cr and Nb and derives strengthening primarily from the Cr2Nb particles. GlidCop material contains fine Al2O3 particles to provide oxide dispersion strengthening (ODS). While GRCop84 is one of the best materials available today, it would be required to develop newer copper alloys with higher strength and creep resistance to improve performance of rocket engines.
Summary: This presentation is about high strength copper alloys for rocket engine applications. The paper will provide an overview of the available copper alloys where properties and associated strengthening mechanisms in the materials will be discussed. While GRCop-84 appears to be one of the best copper alloys available today, it would be desirable to develop new copper alloys with higher strength and creep resistance than GRCop-84 to improve the performance of rocket engines.