In situ analysis of diffusion in metallic components utilizing electrical resistance measurement
Norman Sievers, TU Dortmund University, Dortmund, Germany
Usually it is not possible to observe a diffusion process during high temperature brazing such as joining cemented carbides to steel using copper as a filler metal. In this investigation, a novel setup is introduced to realize an in situ measurement by using the electrical resistance. For this, a 4 wire technique is applied to the specimen to precisely measure the low resistance of the joint within a range of µΩ. By choosing two different holding times on the process temperature of 1150 °C and by analyzing the resulting joint structures, it was possible to correlate the measured signal with the on-going diffusion and bonding process.