| 摘要 |
The invention relates to a cover part for a light source, in particular for a headlight lamp in a motor vehicle headlight. The cover part has a wall with a first side facing the light source and having light-absorbing action. The wall also has a second side away from the light source, that has a reflective action. In order to achieve high light absorption, improved use characteristics under operating conditions which involved high thermal loads, and longer service life, combined with a production method involving a minimum possible capital outlay, the wall of a composite material having a metallic substrate, to which an optically active multilayer system is applied. The multilayer system is composed of a top layer, being a dielectric layer and preferably an oxide, fluoride or nitride layer of chemical composition MeOz, MeFf, MeNs with a refractive index n<1.8, a middle layer being a chromium oxide layer of chemical composition CrOx, and a bottom layer being of gold, silver, copper, chromium, aluminum, nickel and/or molybdenum. The indices x, z, r and s indicate a stoichiometric or non-stoichiometric ratio in the oxides, fluorides or nitrides. |
