Temperature Dependence of the Heat Capacity and Changes in the Thermodynamic Functions of BLi (PbSb15Sn10Li) Lead Babbitt Doped with Lithium

With its high thermal conductivity and excellent compliance with the requirements, lead-based babbitt is commonly used by manufacturers in structures to be subject to shock loading. Since some lead-based babbitt products have a uniform grain structure, they can be used under heavy loads at low constant rates. Lead-based babbitt is a low-cost alloy; therefore, it can be used for general-purpose machines, line shafting, and machine shops. It can also be used in farm machinery, cement equipment, conveyors, elevators, and metallurgical equipment.

One of the most important physical properties of lead babbitt is heat capacity. The paper presents results of studying the temperature dependence of the specific heat capacity and changes in the thermodynamic functions of BLi lead babbitt (PbSb15Sn10Li) doped with lithium in the “cooling” mode in the range of 298.15 to 550 K. For this purpose, the curves of cooling rates of BLi babbitt test samples and a reference sample (lead of grade C00) were processed to derive polynomials that describe their cooling rates. Further, the experimental cooling rates and masses of the reference and test samples were used to establish the temperature dependence of the heat capacity of the alloys and the reference material, which is described by a four-term equation. Integrating the specific heat capacity led to polynomials describing the temperature dependence of changes in the enthalpy, entropy, and Gibbs energy of the alloys. The relationships obtained show that with increasing temperature and lithium concentration, the heat capacity, enthalpy, and entropy of the alloys increase, while the Gibbs energy decreases.