New Opportunities for Brazing Research by in situ Experiments in a Large Chamber Scanning Electron Microscope

The present study demonstrates that in situ heating experiments in a LC-SEM are capable to provide hitherto not accessible insights into the kinetics of the brazing process. Continuous video documentation and temperature logging of the entire experiment yielded the on-set time of the wetting of the base material and the upper time limit that should not be exceeded to avoid quality losses of the joint. For the here investigated system of 75Sn20Cu5Ge filler metal with aluminum alloy EN AW-42100 base metal, the maximum holding time has been determined as 3.5 min at 450 oC. The wetting point at this temperature is reached after one minute, which proves the effectiveness of the here investigated system.