In this study, Ti-6Al-4V and copper were joined through different welding temperatures (825 and 850 degrees C) and holding time (15, 30 and 60 min) diffusion welding/bonding method under argon shielding. The welded joints were subjected to hardness and shearing tests in order to determine their interfacial strength. In addition, microstructural properties of the joined interface were examined using optical and scanning electron microscope (SEM). EDS graphs and diffusion maps of the interface were obtained by carrying out line and elemental analyses. The shearing tests revealed that increasing welding temperature and holding time increased the shearing strength of joined parts. The hardness tests indicated that hardness values increased with increasing distance from titanium to the interface and decreased with increasing distance from the interface to the copper. EDS analyses showed that different reaction areas took place in the welded parts depending on the temperature and holding time.