Rapid Infrared Joining of Titanium-Alloys and Titanium Matrix Composites

A rapid infrared joining (RIJ) technique has been developed at the University of Cincinnati for high temperature materials. This technique takes only a few seconds to a few minutes to join parts up to 1.8 cm in thickness. The advantages of the RIJ technique are quick, simple, inexpensive, no vacuum or pressure needed, no effect on the microstructure of the base material, flexible and feasible for portable operation. For titanium joining, both Ti-6A1-4V and β21S/SCS-6 composite have been successfully joined with infrared at about 1000 °C for 30 seconds in argon with a TiNiCu brazing alloy. The maximum joint shear strength is up to 554 MPa, which is higher than that of any bond joined with conventional brazing techniques. Our study has shown that the longer the joining time, the wider the joining affected zone. Prolonged joining cycles allow for attack of the titanium alloy by the molten brazing alloy. Results from the titanium matrix composite (TMC) joining show that the joining strength for the infrared bonded parts is superior to those processed with the conventional techniques.