Aluminum alloy solder material, its manufacturing method, brazing sheet using this material, and method of manufacturing aluminum alloy heat exchanger using this sheet

摘要

The present invention relates to an Al alloy solder material comprising a composition containing Si in an amount of more than 7.0 to 12.0% or less by weight, Cu in an amount of more than 0.4 to 8.0% or less by weight, Zn in an amount of more than 0.5 to 6.0% or less by weight, Mn in an amount of more than 0.05 to 1.2% or less by weight and Fe in an amount of more than 0.05 to 0.5% or less by weight, or at need, further one or both of In and Sn respectively in an amount of 0.3% or less by weight, with the remainder being Al and inevitable impurities. A brazing sheet clad with the solder material and used for various members of the heat exchanger enables satisfactory brazing at a temperature as low as 570 to 580 C. and is excellent in corrosion resistance. Since the brazing sheet is brazed at a low temperature, a high-strength material having a low melting point is used for a core material of a fin, a tube or the like. Thus, the reduction of a sheet thickness and that of size and weight of the Al alloy heat exchanger are realized. Since this solder material contains Mn and Cu or the like, this solder material has an advantage in being manufactured, namely recycled from scrapped Al alloy heat exchangers or scraps of brazing sheets when manufactured in a factory.