The invention belongs to the field of preparation of
brazing filler metal, and particularly relates to a preparation method of
brazing filler metal. The preparation method of the
brazing filler metal comprises the following steps that the upper brazing filler
metal strip, the at least one middle brazing filler
metal strip and the lower brazing filler
metal strip are welded together under the action of an
electrode roller; the components of at least one middle brazing filler metal belt are different from those of the upper brazing filler metal belt and the lower brazing filler metal belt, and the upper brazing filler metal belt, the at least one middle brazing filler metal belt and the lower brazing filler metal belt are fused into the whole
alloy brazing filler metal during brazing. According to the preparation method of the brazing filler metal, after the multiple brazing filler
metal strips enter the
electrode roller, the composite interfaces of every two adjacent brazing filler
metal strips are melted under the action of resistance heat and form metallurgical bonding under the pressure of the
electrode roller, and the
functional composite brazing filler metal with extremely
high integrity is obtained; on the basis of metallurgical bonding, the brazing filler metal can be conveniently fused into an integral
alloy, the deviation design or
instability condition of brazing filler metal composition is reduced, and it is guaranteed that the expected
welding seam function is achieved.