STRENGTH OF N- AND P-TYPE SKUTTERUDITES~1

摘要

The failure stress distributions of developmental Yb_0.27C0_4Sb_12.08 (n-type) and Ce_0.86Co_1.02Fe_2.98Sbu_11.97 (p-type) skutterudites were measured as a function of temperature. These thermoelectric materials are attractive candidates for use in devices under consideration for power generation sourced from intermediate to high-temperature waste heat recovery. A self-aligning, high-temperature-capable, three-point-bend fixture was developed and used to test specimens whose cross-sectional dimensions were equivalent to those typically used in thermoelectric device legs. The strength of the n-type skutterudite was approximately 115 MPa and independent of temperature to 500°C. The strength of the p-type skutterudite was equivalent to that of the n-type material and independent of temperature to at least 200°C, but its strength dropped by ~20% at 400°C. Compared to other skutterudites, the herein tested compositions have equivalent or even superior strength.