Oxygen getter

Orlov et al. [607] investigated the process of tantalum powder deoxidation using both calcium and magnesium chips as oxygen getters. It is recommended to perform the process with calcium chips at temperature of 900-1300°C for... 

Rare earth metals, as well as alkali earth metals, can be used as oxygen getters in the purification of tantalum powder. Osaku and Komukai [608] developed a method for the production of tantalum and niobium metal powder by a two-step reduction of their oxides. The second step was aimed at reducing the oxygen content and was performed by thermal treatment with the addition of rare metals. The powder obtained by the described method is uniform, had a low oxygen level and was suitable for application in the manufacturing of tantalum capacitors. 

Relatively little work has been done on the effects of refractory-metal additions on the oxidation of Al203-forming alloys. In superalloys, where the refractory-metal concentration is rarely above 10 weight percent, three effects have been observed. One effect is beneficial and arises since these elements can be considered to be oxygen getters in comparison to the base metals (Ni and Co) and they can, therefore, promote the selective oxidation of aluminium and chromium. The other two effects are deleterious. One occurs because the refractory elements decrease the diffusion coefficients of the elements needed to be selectively oxidized. The other arises because of the relatively poor protectiveness of the oxides of the refractory metals, which makes their presence in the external scale undesirable. Refractory metals... 

At the contemplated operating temperatures of approximately o00°C, it was found that uranium has adecjuatc solubility in bismuth when present by itself. However, as the work progressed, it soon became evident that other materials would have to be added to the solution in order to obtain a usable fuel. The present fuel system contains uranium as the fuel, zirconium as a corrosion inhibitor, and magne.sium as an oxygen getter. 

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