Preparing method for brazing filler metal high in tin content

Abstract

The invention discloses a preparing method for brazing filler metal high in tin content. A tin belt with a certain thickness and a brazing filler metal alloy belt with a certain thickness are put into a precise rolling mill together to be subjected to compound rolling, the tin belt is extended, and a tin layer with the uniform thickness is formed on the surface of a brazing filler metal alloy layer, wherein the thickness of the brazing filler metal alloy layer ranges from 0.01 mm to 20 mm, and the thickness of the tin layer ranges from 0.01 mm to 20 mm. The size of the diameter of an inner core of a brazing filler metal alloy is determined according to the size of a filling joint of brazing filler metal, the thickness of the tin layer is determined according to the joint filling property of the brazing filler metal, and the thickness of a coating brazing flux layer is determined according to the difficulty level of removing an oxidization film from the surface of a workpiece. The preparing method is simple, energy conservation and environment friendliness are achieved, the tin content of the prepared brazing filler metal is high, and the thickness of the tin layer is uniform and consistent. Compared with silver-based or copper-based tin-containing brazing filler metal produced in a traditional method, the tin content is high and can be accurately controlled, the forming property is good, and the brazing filler metal can be wound to be in a disc shape or subjected to the next step of machining; and in the brazing process, the low-melting-point tin in the brazing filler metal is melted firstly, and the joint filling property is good.

Description

technical field [0001] The invention relates to brazing filler metal for welding, in particular to a preparation method of brazing filler metal with relatively high tin content. Background technique [0002] Silver-based solder has a moderate melting point, superior brazing process performance, good connection strength, electrical conductivity and corrosion resistance, and has been widely used in machinery, household appliances, tools and other industries. The main alloying elements of silver solder are Ag, Cu, and Zn. In order to meet different performance requirements, elements such as Sn, Cd, Mn, and Ni are usually added. Compared with cadmium-free silver-based solder, cadmium-containing silver-based solder has lower solid-liquidus temperature and good brazing process performance, and has been widely used for a long time, but cadmium is a toxic element , is extremely harmful to humans. The addition of Sn element to silver-based solder can significantly reduce the meltin...

AI Technical Summary

Problems solved by technology

However, the Sn content in the AgCuZnSn solder produced by the above method is low, otherwise its plasticity will be significantly reduced, it will easily become brittle, and it will be difficult to shape it by conventional processing methods