Focus on Multi-Material 3D Printing for Rocket Propulsion Systems at Fraunhofer IGCV

The European space industry is undergoing a transformation: increasing demands for flexibility, cost-efficiency, and rapid development cycles are driving the modernization of launch vehicles. Rocket propulsion systems and attitude control systems, in particular, are considered key cost drivers in the manufacturing of modern space systems. As part of a European research project, researchers at the Fraunhofer Institute for Casting, Composite and Processing Technology (IGCV) are developing innovative additive manufacturing processes for highly complex rocket components. By utilizing 3D printing technologies, the aim is to reduce production costs, shorten development times, and significantly improve material efficiency. At the same time, the project strengthens the competitiveness of the European New Space industry and supports Europe’s independent, sustainable access to space.

Multi-Material 3D Printing Enables Flexible and Customized Aerospace Components

Current research focuses on the additive manufacturing of complex components using multiple materials simultaneously. In modern laser melting processes, various metallic powders or alloys are precisely melted by a laser and selectively bonded together. This results in highly functional components whose material properties, such as strength, temperature resistance, or corrosion protection, can be individually tailored within a single part.

This technology enables designs to be modified directly in the digital realm and produced immediately without the need for additional tooling. "Components can be flexibly adjusted on the computer and subsequently manufactured without delay," explains Constantin Jugert, a researcher at the Fraunhofer Institute for Casting, Composite and Processing Technology (IGCV). This high degree of adaptability significantly shortens development cycles, facilitates rapid design iterations, and reduces lead times in aerospace development by several weeks.

Multi-Material Valves as a Key Technology for Future Ariane Rocket Engines

Leveraging a newly developed additive manufacturing technology, researchers have successfully realized a functional demonstrator for use in rocket systems. This effort resulted in an innovative valve component, fabricated from alternating magnetic and non-magnetic steel alloys, that facilitates precise control and stable orientation of the rocket during flight. By strategically combining different materials within a single manufacturing process, mechanical and magnetic properties can be precisely tailored to meet the specific requirements of modern aerospace applications.

Laboratory tests have already confirmed high component density as well as extremely precise material distribution, critical prerequisites for use in safety-critical aerospace components. Currently, the scientists are comparing their additively manufactured prototype against conventionally milled and welded reference components to systematically evaluate performance, efficiency, production costs, and development cycles. The objective is to demonstrate the technological advantages of additive multi-material manufacturing for future generations of European Ariane engines and to set new benchmarks in rocket propulsion.

Material Boundaries in Multi-Material 3D Printing: New Solutions for Stable Material Bonds

The high degree of design freedom offered by additive manufacturing processes simultaneously presents new technical challenges. The interfaces between dissimilar materials are considered particularly critical areas, as structural weak points can emerge there. Consequently, in a supplementary research project conducted jointly with KU Leuven, researchers investigated how titanium and nickel alloys could be reliably bonded together using a multi-material laser melting process.

Initial test series conducted without an additional transition layer resulted in defective material interfaces and the formation of brittle phases, which can compromise mechanical stability. Through a combination of numerical simulations and experimental laboratory analyses, the research team ultimately developed a solution: an ultrathin interlayer of molybdenum prevents direct contact between the alloys, thereby enabling a stable, metallurgical bond at the laboratory scale.

The insights gained from this work establish, for the first time, a robust foundation for controlled material transitions in additive multi-material 3D printing. This brings ultra-lightweight, highly integrated, and functionally optimized aerospace components within tangible reach, a decisive step forward for future high-performance applications in aerospace engineering.

Process Monitoring in Aerospace Manufacturing

Alongside technological performance, sustainability and process intelligence are increasingly becoming the focal points of additive multi-material manufacturing. To realize both economic and ecological benefits, researchers led by Constantin Jugert at the Fraunhofer Institute for Casting, Composite and Processing Technology (IGCV) are working on new concepts for powder management and quality assurance in additive production.

A specially developed magnetic separation system makes it possible to automatically separate and reuse metal powders that have become mixed during the printing process. This allows for a reduction in material waste and production costs while simultaneously minimizing CO₂ emissions. Looking ahead, the aim is to develop an intelligent process monitoring system in which thermography, sensor technology, and data-driven control algorithms analyze every single melt layer in real time and autonomously optimize manufacturing parameters. These data-driven approaches are considered a decisive step toward stable series production processes and scalable additive manufacturing for the industrial space sector.

More than a dozen research institutions and industrial companies are participating in the European research initiatives Enlighten and Enlighten-ED. Funded with approximately 38 million euros through early 2027, these projects aim to bring multi-material 3D printing technologies to industrial maturity. As a key industrial partner, ArianeGroup contributes expertise derived from real-world space programs and supports the preparatory work for integrating new manufacturing technologies into future European launch vehicles.