AbstractA study of the behaviour of Ag-Cu-Ti braze in contact with a ceramic - its wetta bility, evolution and reactivity-by different means of investigation gives some insight into the mechanisms involved in reactive brazing. Joints between siliconnitride and a structural steel were made by brazing under various conditions of temperature, hold time and a tmosphere. The room temperature mechanical strength measured in a shear test may be correlated to some microstructural and physicochemical features. The heterogeneous microstructure observed for almost all Ag-Cu-Ti brazes is explained by immiscibility in the liquid state with an equilibrium established between Ag-Cu-rich and Cu-Ti-rich liquids. It is shown that high temperatures (>910°C) ensure a more efficient reaction of the titanium-rich phases and so a good wetting of the siliconnitride. Consequently, the shear strengths of bonds between siliconnit ride and steel achieved by using a sufficiently high brazing temperature are optimal (123-158 MPa).