Two methods for the determination of oxygen are reviewed and applied to the analysis of zirconium. The first is indirect and involves combustion of the metal and calculation of the oxygen content by difference. Corrections must be nmde for hafnium and other oxygen absorbing, inert, or volatile contamin,mts and the method is, therefore, useful only for contr()l purposes or where relatively large amounls of oxygen are present.The second procedure is a direct determination of the zirconium oxide content by w~porization ()f the met'd in chlorine gas. The micro-structures of heat; treated zirconium wires with and without added oxygen are shown. They indicate why, in some cases, hardness increased with heating alone. Microhardness measurements on a series of oxygen-doped wires have provided a correlation between oxygen content and hardness. The hardness of zirconium increases roughly 50 V.P.N. for each 0.1 per cent of added oxygen and metal containing more than about 0.2 per cent oxygen is probably not cold workable.
Calculations were made to determine the heat of reaction of calcium with different oxides of vanadium. These calculations indicated better means of controlling the reaction. Ductile rod, wire, and sheet were fabricated from a powder produced by calcium reduction of
V2O3
. Fabrication furnished some information on working and annealing while other studies yielded physical property, purity, and microstructure data.
A process is described for the removal of dissolved oxygen from zirconium by heating the solid metal in molten or gaseous calcium. The equilibrium oxygen‐zirconium ratios have been determined as a function of the time and temperature of treating. Nitrogen is not removed in the treating cycle, and contamination of the treated metal with this impurity may occur. This may be prevented by a careful control of treating temperatures. At high treating temperatures the process may be used for the removal of nitrogen from calcium.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.