Five-sublattice and two-sublattice models have been built to describe the PbX (X=S,Te) semiconductors using the CALPHAD method. The five-sublattice model has three additional sublattices to explicitly model interstitials, electrons, and holes. The experimental literature has been critically reviewed and many high temperature carrier concentration results used in previous assessments have been shown to be unreliable. First-principle calculations for the formation energies of neutral defects and their respective ionization energies have also been incorporated into the models. The models show an improvement over previous assessments of PbTe and are the first time PbS has not been treated as a stoichiometric compound in a CALPHAD assessment.

This paper explores the influence of structural parameters of ultrasonic transducer on the frictional plasticizing heat generation of polymer particles. A three-dimensional model of the interfacial friction plasticizing heating was established, and a transducer with different structural parameters was designed and analyzed. The actual output longitudinal vibration excitation of the transducer obtained by simulation analysis was directly loaded into the heating model, which further investigated the effect of various structural parameters on the frictional plasticizing heating process and temperature distribution of polymer particles. The results demonstrated that the interfacial friction plasticizing heating temperature of polymer particles increases nonlinearly with the longitudinal vibration excitation time, and the heat generation is a transient process. The amplification ratio has the greatest influence on the interfacial friction plasticizing heating rates of polymer particles, followed by both front cover length and piezoelectric ceramic pieces thickness; the effects of length of rear cover, horn and ultrasonic tool head are the smallest. The present work provides an effective basis for further studying the ultrasonic plasticizing of polymer particles in ultrasonic micro-molding.