Microstructural, mechanical, and fractographical study of Ti–CP brazing with low melting point Ti-based filler

With the advantages of great variety, low price, and easy for fabrication, the titanium alloys have been widely used in the aerospace industry. Brazing technique has been researched for manufacturing the complex structure for commercial pure titanium (Ti–CP), such as the heat exchanger and the honeycomb. In order to achieve a strong bond and avoid destroying the basic properties, brazing with a low temperature was applied. A sound joint by filler with low melting point was fabricated with not only high strength but a certain degree of ductility. Two kinds of IMC as ZrNi 3 and TiCu 4 (stoichiometric ratio) were found both in the brazed TA2 joint and that of the brazed honeycomb sample. Due to the dispersed distribution and the multi-slip crystal structure, Cu 4 Ti is considered to be the main reason for the good mechanical properties of the joint. Besides, the formation of TiNi 3 phase was controlled as only 0.24 vol.%. The morphology of the fracture was cleavage and lot of the secondary cracks demonstrated a good toughness of the brazed TA2 honeycomb.