THE MECHANISM OF FLOW OF FILLER METAL INTO BRAZING SPACE——INVESTIGATING THE FLOW CHARACTERISTICS OF LIQUID FILLER METAL IN AN UNPARALLEL CLEARANCE

The main defects in brazed joints are enclosed gas (void) and flux. In the early nineteen sixties the authors noticed that the mode of the flow of filler metal and flux had much effect on the formation of voids and enclosures. It has already been proved by practice that the adoption of unparallel clearance brazing technique enhances the ulti-mate banded area of the brazed joint. In the experiments mentioned in this paper, X-ray with industrial TV aid and cine-camera for recording has been employedto observe the dynamic hehaviour of liquid filler metal. Mainly Sn-Pb filler metal and copper alloy specimens are used in.order to get an intensified X-ray film contrast. Brazing is done in the horizontal position.