摘要 |
Electrical lamps, particularly halogen lamps subjected to high temperatures and pressures, utilize a molybdenum material as holding wires, current connection leads, connecting foils and the like made of a molybdenum material of high purity, which is doped with aluminum present in a quantity of between about 80 to about 800 parts per million (ppm). If the molybdenum has a purity of at least 99.97% (by weight), aluminum may be added in a quantity of between about 150 to 800 ppm, preferably 400 to 600 ppm, and, optionally, a small amount, for example between 5 and 50 ppm, of potassium. The aluminum may, however, also include silicon besides the potassium, present in, for example, between about 270 to 600 ppm, and the potassium between 130 and 330 ppm, with the potassium content being between 0.8 to twice (by weight) of the aluminum, and the silicon content about 1.8 to 3.8, by weight, of the aluminum. The material is made by adding aluminum in an unstable compounds, for example a nitrate, to pulverized molybdenum trioxide (MoO3), reducing the mixture, and then pressing the reduced mixture into a rod or bar, which is then sintered, for example in a furnace.
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