Copper: GRCop 42

Valuable for rocket engine components such as fuel injector faces & combustion chamber linings with regenerative cooling.

Material & Process Capability

GRCop-42 is a copper/chromium/niobium alloy. The alloy was developed by NASA to additively manufacture parts in need of high-strength dispersion and high conductivity. It retains strength at high temperature, due to the use of chromium and niobium in the alloy. Velo3D has developed processes that maintain high density in the printed part. GRCop-42 also has excellent creep resistance, and a low cycle fatigue life.

All of these properties are particularly valuable for rocket engine components such as fuel injector faces and combustion chamber linings with regenerative cooling.

General Process

Velo3D has successfully printed dense components with GRCop-42 using its Intelligent Fusion additive manufacturing process. This data sheet specifies the expected mechanical properties and characteristics of this alloy when manufactured on a Velo3D Sapphire System. All data is based on parts built using Velo3D standard 50 μm layer thickness parameters, using Praxair TruForm CU42-N30, a Velo3D-approved powder. Parts built from GRCop-42 on a Sapphire System can be heat treated like those manufactured by other methods.

Typical Volume Rate1, cc/hr36
Density, g/cc (lbs/cubic inch)8.79 (0.318)
Surface Finish2, Sa, μm (μin)<25 (980) for angles >25° from horizontal

Mechanical Properties at Room Temperature

As PrintedAfter HIP4
Property3Mean -3σMeanMean -3σMean
Ultimate Tensile Strength, MPa (ksi)521 (75.6)533 (77.3)382 (55.4)391 (56.7)
Yield (0.2% Off set), MPa (ksi)292 (42.3)296 (42.9)194 (28.1)198 (28.7)
Elongation At Break, percent14.123.831.334.1
Thermal Conductivity, W/mK25°C303323
1. Geometry-dependent. 2. Depends on orientation and process selected. 3. Mechanical & test samples printed in vertical orientation.
4. HIP conditions: 1750 ± 25 F, 15 ± 0.5 ksi; 3 hours (+15/-0 min) in inert environment.
DS-GRCop42.EN.2022-05-02.v0-6.U.USL 0905-25148_x 2022-05-02. Specifications are subject to change without notice.