Papers by Author: Yan Hong Cai

Abstract: Joining of TE material to electrode is the key technique in the construction of TE device for the practical applications. In this study, a suitable alloy electrode was introduced into CoSb3-based element by means of spark plasma sintering (SPS). Finite element analysis showed that the maximum thermal residual stress appeared at the cylindrical surface zone close to the CoSb3/electrode interface. Microstructure of CoSb3/electrode was investigated by EPMA and the intermetallic compound (IMC) layers were found. The shear strength of CoSb3/electrode joints was tested and the results show that the joints have sufficient strength for reliability of TE device. Electrical contact resistance between CoSb3 and electrode was measured by means of four-probe technique. The results show that the contact resistance was minimal and below the 50μΩ.cm2, which meant the joint exhibited a good electrical contact. The high temperature reliability evaluation showed good thermal duration stability of the CoSb3/electrode joints.

Abstract: In this study, we designed a suitable electrode material was designed, Cu-W alloy, which achieved a good thermal match with CoSb3 thermoelectric (TE) material. By means of spark plasma sintering (SPS), Cu-W alloy was introduced into CoSb3/Ti/Cu-W TE element successfully. Finite element analysis showed that the maximum thermal residual stress appeared at the cylindrical surface zone close to the CoSb3/electrode interface. SEM and EPMA results showed that an intermetallic compound (IMC) layer formed at the CoSb3/Ti interface and EDS analysis confirmed the IMC layer was TiSb phase. Shear tests showed that the shear strength of CoSb3/Ti/Cu70W30 joint was about 50Mpa. The potential profile of the interface area was measured by the four-probe method and the result showed no abrupt change in voltage was found around the interface. The high temperature reliability evaluation showed the joint had high thermal duration stability.