Fraunhofer Institute for Large Structures in Production Engineering IGPDual approach of laser pre-treatment and thermal spraying for the production of intelligent coatings on fiber-reinforced plastics
As sustainability becomes increasingly crucial in the shipbuilding, automotive, mechanical engineering and rail vehicle construction industries, there is a significant demand for smart product innovations aimed towards resource conservation. Although the use of fiber-reinforced plastics (FRP) can fulfil these goals by replacing traditional structures with appropriate lightweight designs, their application is often restricted due to insufficient fire protection and lower abrasion resistance. To compensate for these disadvantages and enable wide range of application, thermally sprayed coatings can be utilized on FRP with suitable pre-treatment through laser structuring.
Problem
Currently, FRP materials are employed in various fields of mechanical and plant engineering because of their outstanding specific stiffness and strength relative to weight. Nonetheless, because of their insufficient fire protection and abrasion resistance properties, these materials are unsuitable for use in shipbuilding and pipeline construction or can only be used to a very limited extent. Because evidence of material properties is generally required in this context, materials and semi-finished products that are currently available on the market often do not comply with the applicable regulations of classification societies. Since they must be considered for ship structure design, it is often necessary to use designs that are significantly less economical, have thicker walls, and heavier component weights.
Solution
The project aims to enhance the properties of FRP materials concerning fire protection and abrasion behaviour through a dual solution approach involving laser structuring of the component surface combined with a thermally sprayed layer, enabling their utilisation in shipbuilding and pipeline construction sectors. The research project will incorporate the existing knowledge of the Fraunhofer IWS in the field of laser pre-treatment processes on high-performance submerged arc lasers, with the aim of maximizing process speed and thereby enhancing structuring efficiency. Afterwards, thermally sprayed coating will be developed at the thermal spray centre situated at the Fraunhofer IGP. To achieve this, tailored coating systems for the specified applications will be created using modern torch technologies. Finally, the integrity of the coating on the coated FRP materials will be confirmed through fire tests and abrasion tests under typical application loads.
Use
It is aimed to demonstrate the efficient pre-treatment of large structures with appropriate process technologies by laser structuring at application-relevant process speeds (around 0.1 m/min). Upon successful scaling up of the area rates, users will be able to utilize the optimized pre-treatment options to prepare parts and components for thermal coating with minimal effort.
In this project, the thermally sprayed coatings are aimed to function as protective coatings to enhance the FRP material's resistance to abrasion and fire, enabling the user to utilize the material across a broader spectrum of applications (e.g., in shipbuilding or pipeline construction). With the broadened scope of application, the possibility of subsequent applications and industrial orders will also be increased. The thermal coating of FRP structures extends beyond the previously mentioned application areas and can be applied in various sectors where such material properties of the fiber composite are required, as well as where they do not fulfil the current regulations and safety standards.
