Abstract:
A tungsten-rhenium filament for an operation temperature between 2900 and 3200null K is disclosed. The filament comprises an aluminum-potassium-silicon (AKS) additive. The filament has a grain microstructure comprising substantially exclusively elongated interlocking grains with a Grain Aspect Ratio (GAR) not less than 12. The rhenium content of the filament is between 0,2-0,4% by weight. A method for manufacturing a rhenium-tungsten filament is also disclosed. The method comprises the following steps. An AKS doped tungsten-rhenium alloy powder is prepared with a rhenium content of 0,2-0,4% by weight. The alloy powder is pressed and presintered, and thereafter sintered with direct current. A rhenium-tungsten filament is formed, which has a metastable crystal structure. The filament is annealed below the recrystallisation temperature, and recrystallised above the recrystallisation temperature. There is also provided a halogen incandescent lamp with a glass envelope enclosing a tungsten-rhenium filament.
Abstract:
A lamp capsule for use in a vehicle headlamp includes a lamp envelope having a tubular portion. First and second spaced-apart filaments are mounted in the lamp envelope for emitting light when energized by electrical energy. The lamp capsule further includes one or more light-attenuating axial stripes on the lamp envelope. The axial stripes are positioned on the lamp envelope for blocking light emitted by the first filament and reflected by the second filament. The lamp capsule may further include light-attenuating rings at or near opposite ends of the lamp envelope for defining upper and lower boundaries of a clear region of the lamp envelope. A filament support structure may include support leads located in the plane of the filaments for limiting light blockage and stray reflections.
Abstract:
In a polarized electrical component, a first electrode is provided at an inner-side bottom face of the component, and a second electrode is provided at an outer-side bottom face of the component. One of the first and second electrodes serves as an anode electrode, and the other serves as a cathode electrode.