Product Code: ICA10_1709

Laser-Based Production of Thin Wear-Protection Films
Authors:
Dominik Hawelka, Fraunhofer ILT; Aachen Germany
Presented at ICALEO 2010

Wear protection coatings are widely applied in the automotive industry to improve tribo-mechanical properties of highly stressed engine components. Today these coatings are produced by physical vapor deposition (PVD) which is a very time consuming production-step. In contrast, sol-gel coating processes have a high potential to be an energy- and resource-efficient technique to produce functional coatings as they do not need expensive vacuum technology or any other elaborate equipment. The major challenge of this process is to adapt a thermal post treatment to turn the amorphous dried gel film into a densely-packed ceramic oxide-layer with the desired properties. Thus, the introduced in-line capable process is a key-step to obtain protection layers on various substrate materials with low thermal stability. Short interaction times between laser beam and work piece make it possible to achieve the necessary high peak temperatures in connection with short heat-penetration depths.
Films of about 1 micron thickness are produced by dip-coating-technology. After drying at temperatures < 250 °C functionalizing of the films is achieved by using diode laser radiation. Hardness measurements via nanoindentation yield values of 600 1000 HV of the laser treated samples. This effect is accompanied by the reduction of surface roughness and layer thickness.