(CuO,Fe2O3)掺杂Ag/SnO2电接触材料的物理性能

Physical Properties of Ag/SnO Electrical Contacts Materials with Co-doping of CuO and FeO

以CuO、Fe2O3为掺杂剂,采用机械合金化方法结合冷压-烧结-热压工艺制备(CuO,Fe2O3)掺杂Ag/SnO2电接触材料。利用X射线衍射(XRD)仪、扫描电镜(SEM)、透射电镜(TEM)、金属电阻率仪、热导率仪和霍尔效应测量仪等分析了不同掺杂比例Ag/SnO2电接触材料的微观结构和物理性能。结果表明:热压可显著改善电接触材料中SnO2颗粒与Ag基体的界面结合;CuO和Fe2O3单一掺杂可分别提高Ag/SnO2电接触材料的导电性能和导热性能,而复合掺杂的Ag-11.5SnO2-0.3CuO-0.2Fe2O3电接触材料的导电导热性能最佳,其电阻率为2.25μΩ·cm,硬度(HV0.5)为748MPa,在室温下的热扩散系数和热导率分别为111.4 mm2/s和338.6 W/(m·K)。复合掺杂的SnO2增强相对Ag基体的平均润湿角为62.7°,界面润湿效果好;SnO2与Ag晶粒之间界面结合良好,SnO2(200)晶面与Ag(111)晶面的界面晶格错配度为14.25%。

MeO-doped Ag/SnO2 electrical contact materials were prepared by mechanical alloying combined with cold pressing-sintering-hot pressing process with CuO and Fe2O3 as dopants.Microstructure and physical properties of the electrical contact materials with different dopant contents were characterized by X-ray diffractometry(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),metal conductivity tester,thermal conductivity meter and Hall Effect tester.The results show that the use of hot pressing process can significantly enhance the bonding strength between SnO2 particles and Ag matrix.Meanwhile,the single doping of CuO or Fe2O3 can improve the electrical performance and thermal conductivity of the MeO-doped Ag/SnO2 electrical contact material.When co-doping of CuO and Fe2O3 is used,the Ag-11.5 SnO2-0.3 CuO-0.2 Fe2O3 material present the optimal electrical and thermal conductivity with electrical resistivity of 2.25μΩ·cm,hardness(HV0.5)of 748 MPa,thermal diffusion coefficient of 111.4 mm2/s and thermal conductivity of 338.6 W/(m.K)at room temperature.A smaller wetting angle of 62.7°between Ag droplets and the(CuO,Fe2O3)-doped SnO2 powders is observed,indicating a better wettability,and the interfaces between SnO2 and Ag grains are well-combined with a lattice mismatch of 14.25%between SnO2(200)and Ag(111).