A new TiBN conductive ceramic powder and its application in copper-based electrical contact materials

Abstract

In this paper, a new TiBN micro-nano powder was synthesized by boronizing sintering method. The TiBN powder exhibits specific micro-nano composite structure, which is composed of TiBN crystal and amorphous layer of nanometer size. The amorphous structure mostly distributes along particle boundary with minimum thickness of 2 nm. The TiBN powder shows combined ceramic and metallic properties with an exordinary electrical conductivity, having an electrical resistivity of 2.655 × 10−5 Ωm (much better than that of TiN, TiCN, TiB2 and TiC). Solid dissolution of B into TiN decreases the number electron of the system and pull down the Fermi level, making the electron present a quasi-linear dispersion contributing to excellent electrical conductivity of TiBN powder. Such TiBN can be used as conductive phase and reinforcing phase in electrical contact materials. Additionally, the TiBN significantly improve the arc erosion resistance of copper-based electrical contact without reducing the electrical conductivity of copper. When the reinforced phase content was 2.5 wt%, the resistivity of Cu/TiBN was 0.26 × 10−6 Ωm, which was only 20.5% that of Cu/TiN. TiO2, Ti3O5, B2O3 and N2 were formed on the surface of Cu/TiBN samples during arc erosion. Such products can significantly enhance the arc erosion resistance of Cu/TiBN electrical contact materials. This TiBN powder synthesis route can be used to prepare bulk materials in engineering materials industry. In addition, it has attractive research value and broad application prospects in photovoltaic cells and energy storage collector applications including lithium batteries, supercapacitors, and fuel cells.