Behavior of titanium in the interfacial region between cubic BN and active brazing alloy

In the present investigation, the diffusion behavior of the element titanium in the interfacial region between Ag-based active brazing alloy and cubic BN grain was investigated by scanning electron microscope and energy dispersion spectrometer, as well X-ray diffraction. Meanwhile, the growth mechanism and activation energy of the reaction layer was also deeply studied from the viewpoint of kinetics. The result showed that the active element Ti concentrated to and reacted with the grain crystal to form TiB2 and TiN to join hard grains and tool substrate. Furthermore, the calculated activation energy value indicated that the width of the interfacial reaction layer was mainly depended on the TiN layer in the special growing process of brazing temperature 880–920 °C and dwell time 300–1200 s.