The railway industry has a high demand for lightweight structures in new trains. We present an overview of 20 years of progress in using laser-based manufacturing techniques to realize such structures, with the recent implementation of Additive Manufacturing (AM) enabling rapid advances. We show how AM-designs reduce car body weight by ~50% over conventional solutions. Moreover, the lifetime of rolling stock is scaling towards 50 years, creating a long-term demand for spare parts. AM offers a strategic solution, creating a digital warehouse, which produces parts only when needed, increasing resilience for the mobility industries.

Further advances in AM-techniques in lightweight manufacture are also being enabled by direct-diode laser technology. Kilowatts of optical power can now be efficiently generated in a compact module mounted on a lightweight process robot and delivered in a small spot onto the workpiece. New functions and operation modes are enabled, e.g. alternative wavelengths, with 780nm operation wavelength selected here, targeting the absorption maximum of aluminum. The 5-fold higher absorption over conventional 1060nm sources will shorten processing times, reduce energy consumption and minimize deformation.

Direct diode techniques are used to produce ultra-compact process heads that integrate laser source, simplified optics for imaging the optical output onto the work surface, and a wire-feed system. The resulting compact AM unit promises high flexibility and low cost and will enable complex shapes such as topology-optimized stiffening structures to be fabricated in limited accessibility environments typical for car body manufacturing. This will support the wide adoption of AM and raise sustainability.