Cu-Ti composite diffusion coating for joining Si₃N₄ ceramic to metal

A method of multiple ion compounds diffusion coating alloy(MICDCA) technology was put forward.The alloy-layer was directly deposited on the Si₃N₄ ceramic surface by MICDCA method,and brazing of Cu-Ti alloying ceramic to metal was realized with MICDCA.The diffusion coating was tested by energy dispersive spectrometer,X-ray diffractometer,scanning electron microscope,optical microscope and anchoring strength scratching test.It was indicated that diffusion coating consist of Cu,Ti,Fe,Si and Al element,and Cu and Ti distributed uniformly.The diffusion coating was made up of Cu₂Ti,Cu,TiSi₂,and anchoring strength of deposited and substrate was well,under the maximum of 100 N,the diffusion coating did not stripped and avalanched from the ceramic substrate.Si₃N₄ ceramic with diffusion coating was joined to metal,and the joining was analyzed using 100 times optical microscope and 5 000 times scanning electron microscope.It was indicated that joining strength was well and there were not obvious macroscopic and microcosmic defects.The method was carried out in a comparatively low vacuum and provided a new method for joining ceramic to metal.