In addition to a small amount of cleaned tungsten wire used as high-temperature furnace heating material, electron tube heater and composite reinforcement external electrode, mostly used for making various kinds of filament incandescent lamp and halogen lamp, gas discharge lamp. For the gas discharge lamp cathode tungsten or tungsten rod, in order to reduce the electron work function, we must add 0.5 ~ 3% thorium, called thorium tungsten wire. As thorium is a radioactive element, the pollution of the environment, the use of cerium instead of thorium as cerium tungsten wire or cerium tungsten rod. But the CE evaporation rate is high, so the cerium tungsten wire or cerium tungsten rod can only be used for small gas power discharge lamp.
Tungsten once after high temperature use after recrystallization becomes very brittle, easily broken in the impact or vibration conditions. In some of the requirements of high reliability in electric light source products, in order to prevent the filament fracture, often adding 3 ~ 5% of rhenium in doped tungsten wire, called tungsten rhenium wire, it can make the tungsten brittle ductile transition temperature dropped to room temperature or below. This is a very strange rhenium effect, has not yet found an element can replace the rhenium, produce the same effect in tungsten.