MICROSTRUCTURE EVOLUTION AT THE Cu-Ti INTERFACE DURING HIGH TEMPERATURE SYNTHESIS OF COPPER-INTERMETALLIC PHASES LAYERED COMPOSITE

摘要

Structural transformations connected with a new processing technique used for fabrication of the copper-intermetallic phases layered composites from copper and titanium sheets were investigated. Formation and growth of intermetallic phases produced at elevated temperatures at the copper-titanium interface were examined for both polyphase diffusion and for process occurring in the liquid phase presence. Since no exothermic peak has been dedected during differential thermal analysis for the Cu-Ti couple, it is suggested that the process of intermetallic phases synthesis is not of the SHS type. Results of the microscope observations and electron probe microanalysis allowed, on the basis of the Cu-Ti equilibrium diagram, to recognize a row of intermetallic compounds that were synthesised in the layer form at the Cu-Ti interface. The measurements have shown that for intermetallics synthesis with the liquid phase contribution the rate of the layer growth exceeds many times the layer growth rate due to polyphase difussion. It was demonstrated that in the way of high temperature synthesis of intermetallic phases with the liquid phase presence the copper-intermetallic phases layered composite can be processed from copper sheet and titanium foil, stocked alternatively into a packet. As-synthesised composite layers containing intermetallic phases are metallurgically bonded with the copper layers.