INFRARED TRANSIENT-LIQUID-PHASE JOINING OF SCS-6 BETA-21S TITANIUM MATRIX COMPOSITE/

Fiber-reinforced titanium matrix composites (TMCs) are among the advan ced materials being considered for use in the aerospace industry due t o their light weight, high strength, and high modulus. A rapid infrare d joining process has been developed for the joining of composites and advanced materials. Rapid infrared joining has been shown not to have many of the problems associated with conventional joining methods. Tw o models were utilized to predict the joint evolution and fiber reacti on-zone growth. Titanium matrix composite, 16-ply SCS-6/beta 21S, has been successfully joined with total processing times of approximately 2 minutes, utilizing the rapid infrared joining technique. The process utilizes a 50 degrees C/s ramping rate, 17-mu m Ti-15Cu-15Ni wt pct f iller material between the faying surfaces; a joining temperature of 1 100 degrees C; and 120 seconds of time to join the composite material. Joint shear-strength testing of the rapid infrared joints at temperat ures as high as 800 degrees C has revealed no joint failures. Also, du e to the rapid cooling of the process, no poststabilization of the mat rix material is necessary to prevent the formation of a brittle omega phase during subsequent use of the TMC at intermediate temperatures, 2 70 degrees C to 430 degrees C, for up to 20 hours.