To obtain an aluminum alloy material for brazing, excellent in pitting resistance, by preparing an aluminum alloy material containing specific percentages of Mn, Cu, Si, and Fe and having specific average grain size.
An ingot of an aluminum alloy, having a composition consisting of, by weight, 0.6-1.7% Mn, 0.05-0.4% Cu, 0.1-0.7% Si, 0.2-0.9% Fe, and the balance Al with inevitable impurities, is heat-treated at 580-640°C for ≥5hr. Subsequently, the ingot is cooled at a rate of ≤200°C/h, further heat-treated at 450-550°C for ≥5hr, and then hot-extruded at 300-550°C, by which an aluminum alloy material having ≤100μm average grain size is produced. By this method, the aluminum alloy material for brazing, excellent in pitting resistance, can be obtained. This material can be suitably used for spacer bar for heat exchanger made of aluminum.
MINODA TADASHI
TATSUATO KEIJI
Next Patent: ALUMINUM ALLOY FOR MACHINING AND ITS PRODUCTION