Microstructure and properties of boron carbide ceramic brazed joints with high nitrogen steel

The reliable joining between B₄C ceramic and high nitrogen steel was obtained using Ag-Cu-Ti filler metal. The wettability and spreadability of Ag-Cu-Ti filler metal with different Ti contents on B₄C ceramics and high nitrogen steel were studied, as well as the microstructure and shear strength of brazed joints were investigated. The results indicated that when the Ti content reaches 4.5wt%, the filler metal possess better wettability and spreadability effect on both B₄C ceramics and high nitrogen steel. The result of microstructure analysis indicated that TiC and TiB exist in the microstructure of brazing joints along ceramic side, while TiFe₂, TiN and CuTi₂ exist along steel side. As a result, the maximum shear strength of brazed joint reached 54 MPa,.