Thermo-Mechanical Models and The Role of Mechanical Behavior In High Efficiency Thermoelectric Couples

摘要

Radioisotope Thermoelectric Generators (RTGs) have been successfully demonstrated in several deep space missions. Several innovations in materials selection and design have been deployed in the development of advanced versions of these devices. The successful development of these devices can be assisted greatly by the use of computer assisted thermo-mechanical modeling. Continuum-based thermo-mechanical models of thermoelectric couple are discussed. Flexural property measurements for an example thermoelectric material, silicon germanium, are discussed in conjunction with fractographic analysis. Weibull plots are presented for mechanically alloyed n-type phosphorus doped SiGe and the failure mechanism for low and high strength failures are discussed. The effectiveness of thermo-mechanical modeling in calculating bulk and interfacial stress distribution in thermoelectric couple and the importance of the role of mechanical properties are established.