The research project aimed to develop a high‑efficiency combustion engine for light commercial vehicles by integrating additive manufacturing, specifically Laser Powder Bed Fusion (LPBF), into the production of critical engine components. The focus was on producing a complex cylinder head and pre‑combustion spark plugs that meet stringent thermal and mechanical requirements while allowing optimized cooling‑channel geometries suitable for a lean‑burn methane combustion strategy.

Technical results show that LPBF was successfully used to fabricate the cylinder head and several variants of the spark plugs from AlSi10Mg and the aluminium alloy CP1. Initial builds of the cylinder head exhibited dimensional deviations exceeding 5 mm compared with the design, indicating issues with laser focus and powder consolidation. Through iterative adjustments of the LPBF process parameters and the application of a Design‑of‑Experiment (DoE) heat‑treatment schedule, the dimensional accuracy was markedly improved. The heat‑treatment routes tested included stress‑relief at 300 °C for 2 h, a T6‑like solution treatment at 530 °C for 30 min followed by water quench, and a T6 ICT process involving a 525 °C solution treatment for 7 h and a 150 °C aging step. Tensile specimens printed in the as‑built state and after each heat‑treatment were measured three times; the length variation within a single specimen remained between 0.1 mm and 0.15 mm, demonstrating consistent dimensional stability. The CP1 alloy, in particular, showed promising mechanical performance and retained its strength after the heat‑treatment cycles, indicating good suitability for high‑load engine parts.

The pre‑combustion spark plugs were produced without measurable deviations from the design, and the printed parts were ready for direct use in the engine test rig. Test prints of the cylinder head were also performed to verify the integrity of the cooling channels; the channels were found to be free of residual powder, confirming the effectiveness of the LPBF process for complex internal geometries. The project demonstrated that, after optimisation, LPBF can produce engine components that satisfy the required mechanical and thermal criteria and can be integrated into a series‑production workflow.

Collaboration within the consortium was led by Rosswag GmbH, which carried out the additive manufacturing, heat‑treatment, and mechanical testing. The consortium, comprising several partners from the automotive and materials sectors, coordinated the project’s activities and agreed on a reduced spare‑part strategy, limiting the number of required replacement cylinder heads to two by combining test content. The project was conducted over a multi‑year period and concluded with a final report (MethMag 19I20014C) that documents the technical findings and outlines the potential for industrial implementation. Funding was provided through a German research grant, supporting the development of advanced manufacturing techniques for next‑generation, low‑emission engines.