| 摘要 |
1530843 Brazeable Al composites SWISS ALUMINIUM Ltd 27 July 1977 [29 July 1976] 31487/77 Heading C7A A brazeable Al composite consists of a core material clad on one surface at least with a brazing alloy which cathodically protects the core. The core consists (in wt. per cent.) of an Al-based alloy containing Mg#0À05, Mn 1-1À5, Cr 0À1-4, Cu 0À1-4, Si 0À01-6, Fe 0À01-0À7 subject to usual impurities (except Mg) such as Zn # 0À5 and Ti # 0À1, and has a microstructure matrix containing Mn, Cu and Cr in solid solution, a uniformα-phase particulate dispersion containing Mn and Fe and a uniform dispersion of MnAl 6 particles which provides galvanic self-protection against intergranular corrosion The cladding consists of an Al-based alloy containing Bi 0À05-0À2, Si 4-14 and optionally Mg 0À5- 3 subject to usual impurities such as Fe#0À8, Cu# 0À5, Mn # 0À3 and Ti # 0À1. Both alloys may be cast and homogenized by heating to 600‹F, followed by heating to 1125‹F at 50‹F/hour. The core is cooled to 1025‹F at 25‹F/hour then air cooled. The cladding is held at 1000‹F for 8 hours before cooling. The composite, made by welding, can be hot (800‹F) and cold rolled, before fabrication into such articles as heat-exchangers, radiators, air-conditioners and gas liquefaction apparatus. |
