Copper-based alloys are becoming ever more essential for additive manufacturing (AM) because of their unique combination of thermal and electrical properties, corrosion resistance, and durability. GRCop-42 is a prime example: a high-conductivity, high-strength copper-based alloy developed by NASA for use in high heat flux applications.
Carpenter Additive produces GRCop-42 AM powder for the aerospace industry and has quickly become the industry standard for additively manufacturing components for liquid rocket engines and other combustion devices. When tested against competitor AM powder, Carpenter Additive’s GRCop-42 stands out for its well-defined, narrow particle size distribution, which has a direct and positive impact on alloy performance.
GRCop-42 is a copper-chromium-niobium alloy with high thermal conductivity, excellent creep resistance, low-cycle fatigue life, and strength retention at elevated temperatures. It is the ideal material for parts such as combustion chamber liners, where:
NASA developed GRCop-42 with the goal of increasing the number of AM materials available for use in harsh environments. To achieve this goal, the alloy wouldn’t just need to be available — it would have to be designed for additive manufacturing. Powder manufacturers would need to produce high-quality metal powder with the correct mechanical properties as well as the correct particle size distribution for optimal flowability, spreadability, and printability.
Particle size distribution (PSD) defines the relative number of particles by size in a powder sample. It shows the range of particle sizes and their relative quantities, typically in a distribution curve format.
A narrow, uni-modal PSD has a single peak and indicates a uniformity of particle size.
A wide PSD shows that particles of many different sizes are present, including much smaller particles called fines <15 µm.
A bi-modal PSD has two distinct peaks and indicates that particles are divided across two main size ranges.
For AM materials, being able to select and control PSD is critical to the material’s performance. A narrow, uni-modal particle size distribution means powder particles are uniform in size, which enables:
Carpenter Additive’s proprietary AM powder manufacturing processes allow for the control of PSD in GRCop-42 production, ensuring its superior quality and proven AM results. Powder particles <2 µm are removed from our powder, which means there is no safety risk from superfine particles. Our GRCop-42 powder has the most stable, unimodal particle size distribution available with the least fines, best flow, and most uniform niobium and chromium distribution. No wonder it’s the aerospace industry standard.