Influence of Lanthanum Additives on the Temperature Dependence of Thermophysical Properties and Changes in the Thermodynamic Functions of Lead Babbitt BLa (PbSb15Sn10)

The article summarizes the results of experimental studies of the temperature dependence of the thermophysical properties and thermodynamic functions of lead babbitt BLa (PbSb15Sn10) with lanthanum additives. The heat capacity of lead babbitt was determined in the "cooling" mode according to the known heat capacity of a reference sample of C2C lead. For this purpose, by processing the cooling curves of lead babbitt samples and reference, equations were obtained that describe their cooling rates. Further, on the basis of the experimentally found cooling rates of the reference and alloy samples, knowing their masses, polynomials for the temperature dependence of the heat capacity of the alloys and the standard were established, which are described by a four-term equation. Using integrals of specific heat capacity, the temperature dependence of changes in enthalpy, entropy, and Gibbs energy is determined. The data obtained show that, with increasing temperature, the heat capacity, heat transfer coefficient, enthalpy, and entropy of babbitt BLa (PbSb15Sn10) increase, and the Gibbs energy decreases. At the same time, lanthanum additives from 0.01 to 1.0 wt % increase the heat capacity, enthalpy, and entropy of babbitt BLa (PbSb15Sn10), while the value of the Gibbs energy decreases.