CoSb3/MoCu热电接头的一步SPS法制备及性能评价

Fabrication of CoSb_3/MoCu Thermoelectric Joint by One-step SPS and Evaluation

Mo-Cu合金电极被成功应用于CoSb3基热电发电元件.通过调节合金中铜的含量,Mo50Cu50合金取得了与CoSb3良好的热匹配.借助于放电等离子烧结（SPS）,Mo-Cu合金通过钛层成功实现了与CoSb3热电材料的连接.在CoSb3/Ti/Mo-Cu界面区域,没有发现微裂纹,扫描电镜（SEM）显示在CoSb3/Ti界面处生成了TiSb相.500℃的热时效实验表明,CoSb3/Ti界面区域的TiSb相厚度略有增加,显示了良好的热稳定性.随着热时效时间的延长,接头的剪切强度降低.四点探针测试表明,界面区域界面电阻很小,界面接触电阻率在20~30μΩ.cm2,显示了热电接头良好的电接触.

Mo-Cu alloy was applied as the electrode material in thermoelectric （TE） device using CoSb3-based skutterudite compounds. Through adjusting the Cu content of Mo-Cu alloy, good thermal match between CoSb3 material and Mo50Cu50 alloy, was achieved. By means of spark plasma sintering （SPS）, Mo-Cu alloy was successfully joined with CoSb3 material through insertion of Ti layer. No crack was observed at the CoSb3/Ti/Mo-Cu in- terracial area showing the joints were well bonded. SEM shows that an intermetallie compound （IMC） layer forms at the CoSb3/Ti interface and the IMC layer is identified as TiSb phase by the EDS analysis. After thermal aging, the thickness of TiSb phase increases. The high temperature reliability evaluation shows the joint has high thermal stability. The shear strength of joints decreases with the aging time increasing. The results of four-probe measurement show that the interfacial resistance of joint is low and the contact electrical resistivity is 20-30μΩ.cm2, which means the CoSb3/Ti/Mo-Cu joint exhibits a good electrical contact.