Medium temperature Ag base brazing filler metal and its preparing method

Abstract

The medium temperature silver base brazing filler metal consists of: Ag 29.5-30.5 wt%, Zn 31.5-32.5 wt%, Mn 2.5-3.5 wt%, Sn 2.5-3.5 wt%, P 0.4-0.8 wt% and La 0.2-0.4 wt% except Cu. The preparation process includes the following steps: selecting material, material throwing and smelting, casting, extrusion and drawing. During the step of material throwing and smelting, electrolytic copper and P-Cu alloy are first heated quickly inside furnace for complete melting, covering agent is added, Zn, Cu-Mn alloy are added successively, Ag and Sn-La are added after lowering the temperature, and the temperature is finally raised to 1050-1100 deg.c while stirring before tapping. The product has the features of no harmful elements contained, relatively low cost, short production process, stable quality and raised extrusion and drawing finished product rate.

Description

Technical field:

[0001] The invention relates to a new low-cost, medium-temperature, cadmium-free Ag-based solder formulation and a preparation method thereof for brazing of ferrous metals, non-ferrous metals and hard alloys. Background technique:

[0002] In the past 30 years, my country's urbanization process has continued to advance, and people have migrated from rural areas to cities, and the demand for supporting urbanized living materials has increased rapidly. For example, the demand for household appliances represented by refrigerators and air conditioners continues to rise, and building decoration materials and their manufacturing industries are also booming. Brazing technology plays an important role in these emerging industries. According to incomplete statistics, only home appliance manufacturing needs to consume 100 tons of Ag solder per year in China, and building materials processing tools needs to consume 200 tons of Ag solder per year in China. In order to ...

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