DISCHARGE LAMP WITH ELECTRODE MADE OF TUNGSTEN ALLOY COMPRISING < 3 WT .% OF RHENIUM

摘要

The invention relates to a high-pressure gas discharge lamp (1) comprising a discharge chamber (4) with a gas filling and electrodes (5) disposed in the discharge chamber. At least one of said electrodes is a tungsten alloy electrode, where the alloy is made of (a) ultra-high pure tungsten and (b) at least one of rhenium, osmium, tantalum, hafnium, iridium, and zirconium in a quantity of 0.01 to 3% by weight of the quantity of tungsten. The tungsten alloy of the invention strikes an appropriate balance between a rhenium or osmium content, which is high enough to obtain sufficient ductility allowing wire processing, and low enough to reduce the amount of rhenium evaporation responsible for blackening the interior of the discharge chamber during operation of the lamp. The invention further relates to a method of manufacturing such a lamp .