Oxidation Of Tungsten And Tungsten Based Alloys PDF Download

The rates of oxidation of W were determined from 1150 to 1 15 C in oxygen pressure of 2 to 100 Torr. Very high rates of oxidation or surface recession rates wer found above 1200 C. An exponential temperature behavior for the rate of oxidation was found for all of the pressure studied. A theoretical analysis of the data usi g the absolute reaction rate theory suggested that the rate of oxidation of tungsten was limited by a mobile absorption process of oxygen onto a tungsten surface already covered by a surface layer of oxide. Oxidation of a 50 w/o Ta-W alloy was studied over the temperature range of 1068 to 1458 C at 152 Torr oxygen pressure. A protective scale was formed on this alloy. The oxidation resistance was improved o a considerable extent over that of either of the pure metals or of other tu gsten-tantalum alloys. A special 250 kv electron diffraction camera was developed for the study of the W-gas reacting interface. Preliminary diffraction data were obtained on the oxidation of W between 800 and 1000 C. (Author).