GRCop-42 – Copper

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 fully integrated 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, CU42-P55, Carpenter CT-GRCop42-AAAA and KBM RocketPowder GRCU42015063ROC, all Velo3D-approved powders. Parts built from GRCop-42 on a Sapphire System can be heat treated like those manufactured by other methods.

Powders: Praxair TruForm CU42-N30 and TruForm CU42-P55

Typical Volume Rate1, cc/hr36
Density, g/cc (lbs/cubic inch)8.79 (0.318)
Relative Density, percent99+
Surface Finish2, Sa, μm (μin)<35 (1378)

Mechanical Properties3 at Room Temperature

After HIP4
Ultimate Tensile Strength, MPaYield (0.2% Offset), MPaElongation At Break, percent
PowderSample SizeMean-3σMeanMean-3σMeanMean-3σMean
Praxair TruForm CU42-N3014837838918719228.933.3
Praxair TruForm CU42-P5536638339118519429.433.4

Thermal Conductivity after HIP4

Thermal Conductivity W/mK
PowderSample SizeTemperatureMean
Praxair TruForm CU42-N30625°C323
260°C317
537.8°C303
1. Geometry-dependent. 2. Depends on orientation and process selected; for angles >25° from horizontal. 3. Mechanical & test samples printed in vertical orientation, machined to ASTM E8
(round specimen #3). 4. HIP conditions: 1750 ± 25 F, 15 ± 0.5 ksi; 3 hours (+15/-0 min) in inert environment.

Powders: Carpenter CT-GRCop42-AAAA and KBM RocketPowder GRCU42015063ROC

Typical Volume Rate1, cc/hr33
Density, g/cc (lbs/cubic inch)8.79 (0.318)
Relative Density, percent99+
Surface Finish2, Sa, μm (μin)<35 (1378)

Mechanical Properties3 at Room Temperature

After HIP4
Ultimate Tensile Strength, MPaYield (0.2% Offset), MPaElongation At Break, percent
PowderSample SizeMeanMeanMean
Carpenter CT-GRCop42-AAAA4336517636.6
KBM RocketPowder GRCU42015063ROC2236418135.5

Thermal Conductivity after HIP4

Thermal Conductivity W/mK
PowderSample SizeTemperatureMean
Carpenter CT-GRCop42-AAAA225°C347
260°C322
537.8°C306
KBM RocketPowder GRCU42015063ROC325°C351
260°C327
540°C321
1. Geometry-dependent. 2. Depends on orientation and process selected; for angles >25° from horizontal. 3. Mechanical & test samples printed in vertical orientation, machined to ASTM E8 (round specimen #3). 4. HIP conditions: 1750 ± 25 F, 15 ± 0.5 ksi; 3 hours (+15/-0 min) in inert environment.

DS-GRCop42.EN.2023-12-6.v1.1.U.USL 0905-25148_B. Specifications are subject to change without notice. ©2023 Velo3D, Inc. All rights reserved. Velo, Velo3D, Sapphire, and Intelligent Fusion are registered US trademarks and Assure, Flow, and Without Compromise are trademarks of Velo3D, Inc. All other product or company names may be trademarks and/or registered trademarks of their respective owners.