BRAZING ALLOY FOR ALUMINUM AND BRAZING SHEET FOR HEAT EXCHANGER MADE OF ALUMINUM

• Main Author: OKUDA YUTAKA
• Format: Patent
• Language: English
• Published: 05.02.1990
• Subjects: ALLOYS; BLASTING; CHEMISTRY; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OFGENERAL APPLICATION; FERROUS OR NON-FERROUS ALLOYS; HEAT EXCHANGE IN GENERAL; HEATING; LIGHTING; MACHINE TOOLS; MECHANICAL ENGINEERING; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METALLURGY; PERFORMING OPERATIONS; SOLDERING OR UNSOLDERING; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS; WELDING; WORKING BY LASER BEAM

PURPOSE:To improve the corrosion resistance of the heat exchanger made of Al by forming a brazing alloy of an Al alloy contg. Si, Fe, Mg and Ti and cladding the alloy to a core material which is electrochemically nobler than this alloy. CONSTITUTION:The brazing alloy for Al contg., by weight, 5-13% Si, 0.05-1.0% Fe, 0.5-2.5% Mg, and 0.06-0.3% Ti, and the balance Al and unavoidable impuri ties is prepd. The brazing alloy is then clad to both surface or one surface of the alloy core material contg. 0.5-1.5% Mn, 0.3-1.0% Cu, 0.1-0.7% Fe, 0.03-0.4% Si, to form the brazing sheet for the heat exchanger. The brazing filler metal is converted to the metal which is electrochemically base to the core material in this way so that the brazing filler metal exhibits a sacrificial anode effect on the core material. The corrosion resistance of the heat exchanger is, there fore, improved.