INFLUENCE OF DIFFUSION BONDING PARAMETERS ON THE STRUCTURE AND PROPERTIES OF TITANIUM AND STAINLESS STEEL JOINTS WITH COPPER INTERLAYER

摘要

Titanium and X5CrNi18-10 stainless steel samples were joined by diffusion bonding using copper foil as a filler metal at temperatures of 850, 875, 900, 925, 950 and 1000°C. The structural examinations have shown significant changes in joints and relatively expansive diffusion zones on the borders of the joined materials. Structures of joints depended on the temperature of the process. The structure of the joint from the titanium site was composed of the eutectoid mixture αTi+CuTi_2 and layers of phases CuTi_2, CuTi, and Cu_4Ti_3. From the stainless steel site of joint in all samples, regardless of the temperature of the process, there were formed layers of FeTi phase, and additionally layers of Fe_2Ti at 925, 950 and 1000°C. Hardness of joints reached higher value than for titanium and stainless steel, and it achieved value from 185 to 580 HV. The hardest phase was FeTi. The maximum shear strength was achieved for joints performed at 900°C.