Molecular Dynamics Simulation Of Mechanical Properties Of Skutterudite Thermoelectric Material

Thermoelectic material is the most important component of thermoelectic generation system. It usually works under the awful condition of periodically changing intensity of sunlight. The resulted circle temperature load and circle mechanical load not only lead to the decline in thermoelectic performance of thermoelectic material, but also greatly affect its long-term stability and reliability. Sometimes thermoelectic material may even fail and lose the ability for continuative work. Therefore, the good thermoelectic performance and reliable mechanical properties of thermoelectic material under service environment are the key to successfully develop out the high efficiency thermoelectic generation system. The study on the mechanical properties and deformation mechanism of thermoelectic material will make important theoretical sense to develop the high efficiency thermoelectic generation system.In this paper, molecular dynamics method is employed to study the mechanical of nanobulk skutterudite CoAs₃ under tension and compression. The basic mechanical properties including stress-strain relationship, elastic modulus and extreme strength are investigated in detail as well as deformation mechanism. The main research contents of this paper are as followed:1. The molecular dynamics program used to calculate the basic mechanical properties of thermoelectic material is written. In order to validate the program, nano single crystal copper is chosen to be object for simulation by expressing the interatomic action with embedded atom method (EAM). The mechanical response of nano single crystal copper under tension and compression are investigated .The effect of temperature and strain ratio on its mechanical properties are also studied. The comparison of the computed results with others' indicated the validity of the written program.2. Skutterudite CoAS₃ belongs to multiatom system and the action between inner atoms is very complicated, so it is difficult to get the potential parameters for molecular dynamics simulation. In order to simplify the calculation, the Morse potential parameters are obtained by the least square fitting.