Special rare earth alloy silver-brazing filler metal

Abstract

The invention relates to a special rare earth alloy silver-brazing filler metal applied to the brazing of the metal workpieces such as copper and copper alloy, cemented carbide, carbon steel, stainless steel, nickel-based alloy and the like, and belongs to a moderate temperature brazing material. At present, no silver-brazing filler metal has excellent performance and low price, so that the development of the brazing field is obstructed. The special rare earth alloy silver-brazing filler metal comprises the following components in percentage by weight: 25 to 35 percent of Ag, 32 to 38 percent of Cu, 1 to 2.5 percent of Sn, 0.5 to 2.0 percent of Ni, 0.01 to 1 percent of Mn, 0.1 to 1.0 percent of Li, 0.01 to 0.5 percent of Si, 0.001 to 0.1 percent of mixed rare earth, and the balance of Zn, wherein the mixed rare earth consists of lanthanum and cerium. The special rare earth alloy silver-brazing filler metal has the advantages of high cost performance, low fusion temperature of brazing filler metals, good wettability and fluidity, high mechanical strength of soldered joint, and good soldering technological property.

Description

technical field [0001] The invention relates to a special alloy rare-earth silver solder, which is suitable for brazing metal workpieces such as copper and copper alloys, hard alloys, carbon steel, stainless steel and nickel-based alloys, and can be widely used in refrigeration, machinery, electromechanical and electrical appliances. It is a kind of medium temperature brazing material in the brazing of industries such as instruments, compressors, etc. Background technique [0002] In the currently commonly used silver solder, the percentage by weight of silver is usually more than 40%. For example, in the Chinese patent whose publication date is May 3, 2006, and whose publication number is CN1765564, a kind of brazing material containing gallium and cerium is disclosed. Cadmium-free silver solder, the weight percent of silver contained in this silver solder reaches about 50%; Another example is that the publication date is March 26, 2003, and the publication number is in the...

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Problems solved by technology

[0003] There are also some silver solders with relatively low silver content at present. For example, the publication date is February 27, 2008, and the publication number is CN101130220 in the Chinese patent, which discloses a cadmium-free silver solder. The silver in the silver solder The content is between 29-41%, but the surface of the silver solder is easily oxidized, it cannot protect the metal surface after brazing, and the wettability of the solder is poor

Another example is that the publication date is May 18, 2005, and the publication number is CN1616182 Chinese patent, which discloses a medium-temperature Ag-based solder and a preparation method thereof, and the silver content in the Ag-based solder is between 29.5-30.5%. , but the mechanical properties of the Ag-based solder brazing cemented carbide and nickel-based alloy joints are not ideal

Another example is that the publication date is September 09, 2009, and the publication number is CN101524793 Chinese patent, which discloses a cadmium-free silver solder containing lithium and niobium and its production method. The silver solder contains niobium with a high melting point , leading to a higher melting temperature of silver solder, which increases the brazing temperature, making the brazing process more complicated, easily causing overheating or overburning of the base metal, and making it difficult to braze the cemented carbide at low temperature

[0004] In summary, there is no silver solder with excellent performance and low price, which hinders the development of brazing field

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