Optimization of the performance of involute splines by new surface treatments (CROSSONT)

Key Info

Basic Information

01.01.2019 to 31.10.2021
Organizational Unit:
Chair of Machine Tools, Gear Technology
European Union EU

Research partner

    • Leibniz-Institut für Werkstofforientierte Technologien – IWT
    • Bremer Institut für angewandte Strahltechnik – BIAS
    • Safran S.A.



+49 241 80 26385



Present Situation

Clean Sky 2 aims to reduce CO2, NOx and noise emissions in order to maintain the quality of life in Europe through environmental protection. At the same time, the competitiveness of the aviation industry must be strengthened in international competition in order to secure and create jobs. Therefore, the targets of ACARE 2020 will facilitate the first steps to the Flightpath 2050 targets that include 75% cut of CO2 and 90% of NOx emissions as well as 65% noise reduction. The overall objective of the CROSSONT project is to find new surface treatments and coatings that allow spline joints to be more resource efficient, e.g. increasing their power density. This contributes to the overall goal of the Clean Sky 2 joint undertaking of reducing CO2 and noise emissions of aircrafts by enabling lightweight aerospace power train designs.

Objective and Approach

CROSSONT will contribute to these ambitious emission reduction goals by providing innovative material processing approaches to push the Ultra High Bypass Ratio (UHBR) technology. The Ultra High Bypass Ratio technology has been identified as a promising approach to reduce aircraft engine emissions and fuel consumption. UHBR applies a reduction gear box that reduces the fan speed and allows the implementation of larger fan diameter. Modelling of the spline will be conducted to predict its behaviour. It is the consortium's conviction that outstanding surface properties for crowned splines in UHBR applications can be generated with a combination of laser and physical-vapour-deposition (PVD) processes.

This website is part of a project that has received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No 821344.