Electric Furnace for Operation in Oxidizing, Neutral, and Reducing Atmospheres to 2400°C

Abstract

A simple resistance‐heated furnace has been developed for operation at temperatures up to 2400°C in oxidizing as well as neutral or reducing atmospheres. The sample to be heated is placed in a dense zirconia tube, which is mounted inside a vertical split‐tube tantalum heating element. Any desired atmosphere may be used inside the zirconia tube without damaging the heating element, which is operated in argon. The heating element, which is also protected by the zirconia tube from attack by vapors from the sample, is surrounded by tantalum heat shields in a water‐cooled outer shell. A temperature of 2400°C was reached in a 2.22‐cm‐i.d. zirconia tube at a power level of 8 kW, and 2200°C was reached in a 3.5‐cm tube using 6.5 kW.