Solid state diffusion bonding of titanium to steel using a copper base alloy as interlayer

Dissimilar titanium/steel metals were successfully joined by diffusion bonding process with the help of a copper-based interlayer. The appropriate processing parameters have been investigated and the joints were analyzed by means of scanning electron microscopy (SEM), microhardness measurement, shear strength test, and X-ray diffractometry (XRD). The results show that the joint could not be bonded at a temperature lower than 800 degrees C even at holding time of 180 min. However, at 850 degrees C successful joining was achieved at all holding times. on the other hand, atom diffusion and migration between Ti and Fe or C were effectively prevented by adding a copper-based interlayer and hence, Fe-Ti and Ti-C intermetallics were not formed in the joint. This technique provides a reliable method of bonding titanium to steel. (C) 2008 Elsevier B.V. All rights reserved.