Mesothermal copper based solder without cadmium, and preparation method

Abstract

A medium-temp non-Cd Cu-based soldering wire contains Cu (74.9-82.96 Wt%), Ni (1-5.5), Sn (10-12), P (6-7), Ce (0.02-0.3) and La (0.02-0.3). Its preparing process features that after the electrolytic Cu and Ni in the graphite crucible of MF induction furnace is heated to 600-800 deg.C, the covering agent is added. Its advantages are low smelting temp, narrow smelting zone, better wet spreading performance and certain plasticity.

Description

technical field [0001] The invention relates to a solder used for brazing. Background technique [0002] In the past 30 years, the demand for household appliances represented by refrigerators and air conditioners has continued to rise, and building decoration materials and their manufacturing industries have also flourished. Brazing technology has played an important role in these industries. According to incomplete statistics, only the manufacture of home appliances requires 100 tons of silver solder per year in China, and 200 tons of silver solder is consumed annually in the country for processing tools for building materials. In order to pursue brazing process and technical economy, brazing workers often prefer silver-based cadmium-containing solder, especially in the production of refrigeration accessories, almost all of which use cadmium-containing solder. This is because the addition of Cd to the Ag-Cu-Zn ternary alloy can significantly reduce the liquidus of the allo...

AI Technical Summary

Problems solved by technology

It mainly includes two series of silver-based solders and copper-based solders, but there is still a certain gap compared with cadmium-containing solders in terms of melting temperature and melting range technical indicators. In addition, some silver-based solders are filled with a lot of precious Alloying elements make it difficult for this kind of solder to be widely used. Although the price of copper-based solder is low, the alloying elements added to obtain a lower melting temperature make the solder very brittle and difficult to process into welding wire. It can be made into foil solder or powder solder by rapid solidification, which limits its scope of use