DIFFUSION PROCESSES AND FORMATION OF STRUCTURE OF BRAZED JOINTS ON TITANIUM ALUMINIDES

Results of investigations of chemical heterogeneity of the brazed joints on titanium aluminides produced by using eutectic filler metals of the Ti-Zr-Fe system and the high-temperature vacuum brazing process are presented. The effect of the diffusion processes occurring at the filler metal – base material interface on chemical composition and morphology of the brazed seams is shown. Investigation of the kinetics of diffusion saturation of filler metal with aluminium allows suggesting the mechanism of formation of a two-phase structure of the seams, close to that of the base material, which requires holding for 1.0 h. It is shown that levelling of the concentration of aluminium at the interface with the base material takes place during t = 1.5 s at a gap width of 50 μm.