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Thermal analysis of nonisothermal oxidation parameters of zirconium powder
Vladimir I Sukharenko, Lidia I Borisova, Kira B Zhogova, Ivan K Kremzukov

The possibility of applying methods of differential thermal analysis (DTA) and thermogravimetry (TG) to the study of nonisothermal oxidation of metals is demonstrated, with zirconium as an example. The zirconium powders studied were produced by the sodium-thermal and electrolytic methods as well as by the electrolytic method with further grinding in a ball-mill in alcohol for different time intervals. It was found that zirconium oxidation covers several stages corresponding to the oxidation of different-sized zirconium particles, which is confirmed by the increase in the thermal effect for a fraction of small particles depending on time of grinding and by its decrease for a fraction of large ones. It is also found that grinding affects heat evaluation rate and initial oxidation temperature, which is explained by the occurrence of a tribochemical effect. In order to increase this effect, it is proposed to introduce a liquid passivating agent into the ground powders.

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