The invention relates to novel insoluble non-corrosive aluminum
soldering flux and a preparation method thereof, belongs to insoluble non-corrosive aluminum
soldering flux and preparation technology thereof, and in particular to insoluble non-corrosive aluminum
soldering flux containing a
potassium composition, an aluminum composition, a cesium composition, a
silicon composition and a
fluorine composition and preparation thereof. The insoluble non-corrosive aluminum soldering flux solves the problems of poor wettability of solder, increase of the
welding difficulty and influence of the braze
welding quality during braze
welding because aluminum is active and compact and stable
oxide is easy to form on the surface of the solder. The preparation method adopts a technical proposal that the preparation method comprises the following steps: firstly, making the aluminum composition react with
hydrofluoric acid, and adding the
potassium composition and the cesium composition in turn; secondly, adding hydrofluosilicic acid into the mixture for reaction after the reaction is over; and thirdly, performing
dehydration,
drying, crushing and sieving through 20 mu m
sieve, and preparing the insoluble non-corrosive aluminum soldering flux. The insoluble non-corrosive aluminum soldering flux has the advantages of convenient use, protection of
brazing metals and the solder from being continuously oxidized during heating, improvement of the wettability of the solder on the surfaces of substrate metals, promotion of flowing of the solder, filling of joint gaps, formation of braze welding seams with clean and compact surfaces, and the like, and can be widely applied to braze welding of aluminum workpieces and aluminum
alloy workpieces.