TRW Automotive, the world market leader in the development of integrated safety systems for the automotive industry, has employed the PlasmaPlus® technique for applications with highest requirements for resistance against environmental conditions such as corrosion avoidance, thermal resistance and splash water stability since 2007.
The technique developed in collaboration with Plasmatreat and the Fraunhofer IFAM is applied to engine pump units made from aluminium pressure die castings in order to prevent corrosion. These units are integral components of servo steering systems for a multitude of vehicles and subject to high reliability requirements. Subsequent integration into the final assembly process was possible with little effort, with no disruptions to production and has provided TRW Automotive with a pre-treatment feature that can be easily applied upon customer’s request.
The adhesive bonding seams of the aluminium component surfaces are initially cleaned and activated with Openair® plasma. Immediately thereafter, they are selectively coated in-line with PlasmaPlus® at atmospheric pressure conditions. Plasma polymerization provides a maximum degree of protection against ingress of moisture. The mechanical and, above all, the corrosive loads acting on the component during its operating life must not cause a failure of the bonded joints since otherwise the electric engine and its electronic equipment would no longer be protected. With the use of the plasmapolymer coating, a considerably better resistance against environmental conditions has been achieved over non-coated components.