Effect of calcium additive on the kinetics of oxidation of solid lead babbit B(PbSb15Sn10)

The paper considers the results of a study on the oxidation kinetics of lead babbit B(PbSb15Sn10) with calcium in a temperature range of 373–473 K. In addition, the resulting oxidation products of alloys and their microstructure are examined. The studies were carried out using the thermogravimetric method in air at atmospheric pressure within the temperature range of 373–473 K. It was found that the oxidation process in the entire studied temperature range can be accurately described by a degree four polynomial. In the experiments, a variation in the oxidation rate was measured over time. The kinetic and energy parameters of the alloy oxidation process were determined. It was found that calcium additives increase the oxidability of the initial alloy B(PbSb15Sn10) in the temperature range of 373–473 K. It was demonstrated that the additives of the alloying component significantly alter the alloy microstructure. X‑ray diffraction analysis revealed that the oxidation products of lead babbit B(PbSb15Sn10) with 1.0 wt % calcium include the following oxides: Pb₂Sn₂O₆; PbO; Sn₂O₄, SnO, Pb_0.866O_{2, Sb2O5}, Ca(Sb₂O₆), and Ca₂Sb.