| 摘要 |
PROBLEM TO BE SOLVED: To provide a brazing sheet for a heat exchanger, which has superior mechanical strength and the superior corrosion resistance of the outer part in a high-temperature environment. SOLUTION: The brazing sheet 2 for the heat exchanger has a core material 2a made from an aluminum alloy containing Si, Mn, Cu and Mg and a soldering material layer 2b which is provided on one side or both sides of the core material 2a and is made from an aluminum alloy containing Zn and Si, and shows a tensile strength of 60 MPa or higher when an actual temperature of a substrate after having been soldered is 150°C. In the soldering material layer 2b, a difference between dissolved Si concentration in a primary crystal and that in anαphase of an eutectic is 0.05 mass% or less. As for a potential gradient of the soldering material layer 2b, the potential is the basest on the top surface and becomes nobler in a thickness direction from the top surface by 0.5 mV/μm or more. COPYRIGHT: (C)2009,JPO&INPIT
|
