THE PROJECT: PROCESS PARAMETER DEVELOPMENT OF GRCOP-42

GRCop-42 plays a crucial role in rocket engines, rapidly dissipating heat to ensure optimal performance in the demanding space industry. The copper-chromium-niobium alloy is part of the broader GRCop alloy group developed by NASA. GRCop-42 specifically features not only a high thermal conductivity as other copper alloys, but also high strength achieved by dispersion strengthening. Common applications are within liquid rocket engines, which naturally require thermal stability and creep resistance.

CHALLENGES & OBJECTIVES:

The space industry’s demand for GRCop-42 is soaring, and limited powder supply and service providers posed significant challenges. The objectives were to create a robust material parameter solution and supply chain for GRCop-42 to enable a ready-made solution for service providers to rapidly adopt a stable process and print space components using this material. The material parameters needed to be scalable to large format machines, such as the NXG XII 600 and able to achieve high density and stable properties over the build volume in single- and multi-laser overlap regions.

DEVELOPMENT OF GRCOP-42:

Powder supply was enabled by Nikon SLM Solutions global production partnership, in which the powder quality is specified, and each batch screened internally by quality control. Two different SLM®280 Twin 700W machines were used during initial development to ascertain transferability across systems. Parameter development followed Nikon SLM Solutions robust protocols and demonstrated that GRCop-42 can be successfully printed on SLM® systems, offering comparable or even superior results to other L-PBF platforms and methods.

In the additive manufacturing (AM) industry, parameter development often begins with a limited number of small test samples. While this method can yield excellent mechanical properties in small specimens, scaling up to larger, more complex components presents challenges.

To address this, Nikon SLM Solutions takes a comprehensive approach to parameter development. This includes an in-depth analysis of laser hatch parameters, border contours, and up- and downskin settings to enhance surface roughness. The most effective parameters are rigorously tested through high-exposure area builds to ensure consistency across the entire platform—achieving a best-in-class density of 99.97%.

Before finalizing a parameter release candidate, it undergoes additional testing with multiple approaches. A series of qualification builds then provides statistical mechanical property data across the entire platform and multiple builds. These results offer a realistic view of the as-built (non-HIP’ed) mechanical properties expected in high-exposure jobs. When applied to large components with varying wall thicknesses and HIP treatment, mechanical properties can significantly surpass these values.

Another critical aspect of parameter development is fine-tuning scaling factors and beam compensation values, which are essential for achieving high-precision parts. Nikon SLM Solutions ensures these adjustments are optimized and validated using standardized test artifacts of various geometries and sizes. The accuracy criteria follow established industry standards, such as ISO 27681.

PARAMETER TRANSFERABILITY FROM SLM®280 TO NXG XII 600:

During the development of the NXG XII 600, it was essential to understand how parameters from core systems like the SLM®280 2.0 could be transferred. By establishing a strong correlation between machine settings and process parameters, Nikon SLM Solutions reduced the cost of parameter development for NXG systems. This allows customers to conduct lower-cost experiments on core systems before scaling up to high-productivity, large-format machines.

The same approach applies to GRCop-42. With the NXG XII 600’s advanced capabilities—such as high laser power and the ability to significantly magnify spot size using zoom or defocus—parameters can be further optimized for greater robustness and efficiency. As a result, the NXG XII 600 can produce parts within its 600 × 600 × 600 mm build chamber using up to 12 lasers, dramatically reducing build times.

ADVANTAGES AND PERFORMANCE IMPROVEMENTS:

The development work exemplified Nikon SLM Solutions‘ commitment to provide solutions to GRCop-42, paving the way for broader adoption in the space industry. Nikon SLM Solutions allows for reduced supply chain schedules and improved the prospects for future space projects. These results combined with SLM’s open architecture allows scaling the parameter set up to larger platforms such as the NXG XII 600 and NXG XII 600E with a 1.5-meter build height.

OUR MISSION, TO EMPOWER YOURS

To learn more about how Nikon SLM Solutions can help you optimize your manufacturing processes, please contact our team.