Method for brazing aluminium alloy material containing magnesium using a flux comprising potassium fluorozincate

摘要

The present invention relates to a method for brazing a magnesium-containing aluminum alloy material exhibiting excellent brazing performance with an aluminum alloy material containing 0.2-1.0% of magnesium used in cladding parts of vehicle heat exchanger tubes and the like, with potassium fluorozincate and with an Al-Si-alloy brazing material in an inert gas atmosphere. The method is characterized by brazing the magnesium-containing aluminum alloy by applying potassium fluorozincate having a composition of KxZnyFz (wherein x, y, and z are positive integers) to the brazing part at a concentration of (1.65 × Mg% /T) g/m2 or more, wherein T is an average temperature rising rate (°C/second) of the aluminum alloy from 550°C to the brazing temperature, and heating at an average temperature rising rate (T) of 0.1°C/second or more.