Cylinder head gasket
In order to optimally seal the combustion chamber, an optimal balance between engine component distortion and gas seal compression is necessary.
BrazeTec and development partner Federal Mogul Sealing Systems have developed a metal suspension which can be applied to steel layers in a contour-stable way and which acts as a blocking-layer after being brazed.
Here, the suspension is applied to the finished shaped support layers in a screen printing process.
Due to its high adhesion and corrosion-resistance, a mixture of nickel-based alloy NI 102 and a high melting point additive Ni80Cr20 was used. The working temperature is about 1050°C.
Hydrogen was used as the brazing atmosphere. The blocking-layer thickness can be varied as desired from 0.04 mm up to 0.12 mm. The brazing is carried out without flux in a continuous furnace with an inert gas.
The following requirements had to be fulfilled with regard to the brazing suspension:
- sharp-contour paste-application in the screen printing process
- good edge gradient on the printed layer
- no running of the brazing paste on being heated up
- residue-free burn off of the binder system in the inert gas atmosphere
- smooth, pore-free and crack-free surface on the applied layer
- reproducible setting of the required functional quantities
- shape-stable application, no flowing of the alloy
- good resistance to temperature and temperature change
- corrosion-resistant coating
