Influence of tellurium on oxidation kinetics of lead-antimony alloy in solid state

The solution of many problems of modern technology is associated with the use of materials with high resistance to oxidation. Therefore, the study of interaction of oxygen with metals and alloys has acquired great importance in connection with the recent widespread use in various fields of science and technology of new materials with specific physicochemical properties. In this series, a special place is given to lead alloys with antimony, copper, tin, tellurium and other metals. There is no information in the literature on heat resistance of these lead alloys alloyed by tellurium. The oxidation process of alloys has been studied in air under isothermal conditions by means of thermogravimetric method with continuous fixation of sample mass during an hour. Based on experimental data, the kinetic curves of oxidation of lead-antimony alloy have been constructed, which used to determine the specific weight gain from the amount of tellurium, duration and temperature. According to the research results, it has been found that tellurium additives up to 0.5 % increase the oxidation rate of lead alloy, which is accompanied by a decrease in apparent activation energy of oxidation process. By constructing the quadratic dependences of specific weight gain of alloys on duration of oxidation, the mechanism of oxidation of the alloys has been defined. It has been shown that the process of alloys oxidation in studied temperature range 473-573 K is obeys to a hyperbolic dependence. (author)