Abstract:In order to ensure that the signal can be transported correctly, the microwave devices made of aluminum alloys must be assembled and brazed flaw-freely. A new approach of using contact reactive brazing (CRB) process to realize the compact brazing of aluminum alloys is put forward. The reason for this is that CRB, which realizes bonding depending on the liquid alloy produced by metallurgical reaction between the materials to be joined, overcomes the limitation of traditional brazing that the macroscopically disorganized filling flow of liquid filler metal would result in defects in brazed seam. Joint of LF21 (AA3003) with the compactness of over 95% is brazed by the method of CRB using Si powder as an interlayer. At last, the influence of the physical parameter related to the Si powder interlayer on the compactness of the joints is investigated in detail.

Key words:   microwave devices; brazed seam compactness; contact reactive brazing; defects