STRENGTH OF N-AND P-TYPE SKUTTERUDITES

摘要

The failure stress distributions of developmental Yb_(0.27)Co4Sb_(12.08)- (n-type) and Ce_(0.86)Co_(1.02)Fe_(2.98)Sb_(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.