Copper-based brazing filler metal capable of accurately controlling using amount of brazing flux and good in brazing seam protection effect

Abstract

The invention belongs to the field of welding materials, and particularly relates to copper-based brazing filler metal capable of accurately controlling the using amount of brazing flux and good in brazing seam protection effect. The copper-based brazing filler metal comprises a round or oval copper-based brazing filler metal inner wire and a protective film; the protective film is prepared from 10%-12% of zinc phosphide powder, 5%-7% of kyanite powder, 3%-5% of glass fibers, 2.5%-3.5% of nano silicon dioxide powder, 10%-12% of boric anhydride powder and 20%-25% of potassium fluoborate powder which are all treated by the aid of a coupling agent, 5.5%-6.5% of a curing agent and the balance epoxy resin. In the preparation process, the wire breakage phenomenon is avoided, the wettability of the brazing filler metal is high during brazing, and gaps between workpieces to be welded can be effectively filled; during brazing, the using amount of the brazing flux can be accurately controlled, and the problem that the using amount of the brazing flux is not enough during brazing or a large amount of the brazing flux is left after brazing is solved; during brazing, the protection effect on brazing seams is good, the protection layer is easy to remove, the brazing seams have few defects, and the strength is high.

Description

technical field [0001] The invention belongs to the technical field of welding materials, in particular to a copper-based solder that can precisely control the amount of flux and has a good protective effect on brazing seams. Background technique [0002] With the rapid development of industrial technologies such as automobiles, microelectronics, electrical appliances, tools, refrigeration, exploration, tunneling, aerospace, etc., brazing technology has been widely used in these fields due to its unique advantages. For copper alloys, copper-based solder is required for brazing. Generally, copper-based solder is used in conjunction with flux. Flux is used to remove the oxide film on the surface of the base metal and protect the brazed joint from oxidation. [0003] At present, there are two types of copper-based solders commonly used: solid solder and cored solder. During the preparation and use, there are the following technical problems: [0004] (1) When using solid coppe...

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