Abstract

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.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.