A kind of high-strength silver-based solder containing graphene and its melting method

Abstract

The invention discloses a graphene-containing high-strength silver-based brazing filler metal. The graphene-containing high-strength silver-based brazing filler metal is prepared from, by weight, 65.0-99.5 parts of silver or silver alloy, 6.5-26.5 parts of metalized graphene, 0.5-9.6 parts of rubidium and 0.1-0.3 part of microelements in a smelting mode. A smelting method comprises the steps that the raw materials are weighed accurately in proportion; the metalized graphene and 55-70% of silver or the silver alloy are smelted through a vacuum smelting furnace to prepare a silver / graphene alloy Al, then the rubidium and 24-29% of silver or silver alloy are smelted in the vacuum smelting furnace to prepare an alloy A2, and the microelements and the rest of silver or silver alloy are smelted in the vacuum smelting furnace to prepare an alloy A3; and the alloy A2 and the alloy A3 are added in sequence after the alloy A1 is smelted, a molten silver-based alloy is obtained, and the silk-shaped or strip-shaped silver-based brazing filler material is obtained after the molten silver-based alloy is processed through a conventional method. The researched and developed graphene-containing high-strength silver-based brazing filler material does not contain poisonous or harmful elements such as Cd, Pb and Cr, and is environmentally friendly, moderate in smelting temperature, good in wettability and high in strength.

Description

technical field [0001] The invention relates to brazing materials, in particular to a high-strength silver-based solder containing graphene, and also relates to a melting method for the high-strength silver-based solder. Background technique [0002] As the most widely used type of hard solder, silver-based solder has moderate melting temperature, good wettability, excellent joint filling ability, good connection strength, toughness and conductivity, and is widely used in aerospace, household appliances, electronics, etc. Indispensable and vital welding materials for industries such as At present, the methods for preparing silver-based solder mainly include smelting alloying method, powder electromagnetic pressing method, in-situ synthesis method, rapid solidification method and so on. However, the connection strength of the silver-based solder prepared by the above method is low, and the tensile or shear strength of the brazed joint is low due to the low mechanical propert...

AI Technical Summary

Problems solved by technology

However, the connection strength of the silver-based solder prepared by the above-mentioned method is low, because the mechanical properties of the silver-based solder itself, especially the low strength, lead to low tensile or shear strength of the brazed joint.

When brazing high external force (above 700 MPa) and large static structural parts, the existing silver-based solder can no longer meet the performance requirements of related technical and engineering fields

[0003] "King of new materials" graphene is a new type of two-dimensional material with the highest strength at present. In the field of solder-based solder, it is expected to overcome the low connection strength of the existing silver-based alloy solder and develop a new type of high-strength silver-based solder

[0004] The invention patent "A Silver Brazing Paste and Its Preparation Method" (ZL 201610125808.1) discloses a method of preparing silver solder paste by grinding graphene powder + carrier + brazing flux + silver solder powder, although graphene powder has It can be uniformly dispersed in a carrier with a certain viscosity, but due to the large difference in physical and chemical properties between flux and silver solder powder, it cannot be uniformly dispersed in the carrier even by grinding flux and solder powder, which will lead to poor connection performance of silver solder paste , cannot guarantee the reliable connection of weldments

At the same time, the silver solder powder used in this patent is AgCuP, AgCuZn, AgCuZnCd, and the solder powder contains P and Zn evaporative elements. In the connection between vacuum system and vacuum components, the silver solder paste proposed in this patent will not be able to connect reliably. At the same time, Cd is Toxic elements, so the patent has certain limitations

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