Compressive creep behaviour of hot-pressed PbTe

Creep deformation is of concern in PbTe thermoelectric modules operating for years at high homologous temperatures while being subjected to internal or external stresses. The creep strain rates of hot-pressed PbTe are measured at 400 °C; a power-law is found, with a stress exponent n = 1.7 at low stresses (2–7 MPa) and n = 4.4 at high stresses (7–35 MPa). Creep rates measured at low stresses (4–6 MPa) between 350 and 500 °C provide a creep activation energy Q = 181 ± 18 kJ/mol. The creep parameters and the good hot ductility of PbTe are compared to those for cast Bi₂Te₃ reported in the literature.