Journal of Materials Research and Technology (May 2024)

Cyclic oxidation behaviour of N-type (Zr,Ti)Ni(Sn,Sb) and P-type (Zr,Ti)Co(Sn,Sb) thermoelectric materials

  • Mikdat Gurtaran,
  • Zhenxue Zhang,
  • Xiaoying Li,
  • Hanshan Dong

Journal volume & issue
Vol. 30
pp. 7476 – 7484

Abstract

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In this study, the fabricated Hf-free N-type (Zr,Ti)Ni(Sn,Sb) and P-type (Zr,Ti)Co(Sn,Sb) thermoelectric materials were subjected to cyclic oxidation testing at 500 °C for 10, 30, and 50 cycles. The oxidation behaviour of the materials was systematically investigated by evaluating mass gain to study the oxidation kinetics and by analysing surface morphology, phase constitution and elemental distribution to investigate the oxidation mechanism. The results indicated that both of the materials were severely oxidised during the cyclic oxidation testing, and the mass gain followed the parabolic kinetics and the parabolic rate constant (kp) being 0.006165 mg2cm−4s−1 and 0.000109 mg2cm−4s−1 for the N-type and the P-type TE materials, respectively. Alternated multilayers of Ni3Sn4+SnO2+(Zr,Ti)O2 and CoSb + SnO2+Sb2O4+(Zr,Ti)O2 were identified on the surface of the N-type and P-type materials, respectively, after the cyclic testing, which would deteriorate the thermoelectric performance of the materials. The outcome of this study strongly suggests that it is essential to improve the oxidation resistance and the thermal stability of the N-type (Zr,Ti)Ni(Sn,Sb) and P-type (Zr,Ti)Co(Sn,Sb) thermoelectric materials for high-temperature applications.

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