Abstract: A brazing method includes shaping a clad sheet to form a hollow structure. A tube is then partially inserted into a through hole in the hollow structure, thereby forming an assembled aluminum structure. The exterior surface of the hollow structure adjacent the through hole is composed of an Al—Si alloy that serves as a first filler material. The interior surface of the hollow structure adjacent the through hole is composed of an Al—Si alloy containing at least one of Cu and Zn and having a solidus temperature of 570° C. or less that serves as a second filler material. The assembled aluminum structure is brazed by heating it in an inert-gas atmosphere such that fillets joining the hollow structure to the tube along the through hole are formed first on the interior surface of the hollow structure and then on the exterior surface of the hollow structure.

Abstract: A brazing method includes shaping a clad plate to form a hollow structure. The clad plate has at least one layer containing an element that breaks down an oxide film when heated. A tube is then partially inserted into a through hole in the hollow structure, thereby forming an assembled aluminum structure. The exterior surface of the hollow structure adjacent the through hole is composed of an Al—Si alloy that serves as a filler-material layer. The exterior surface of the tube that opposes the through hole of the hollow structure is composed of aluminum or an aluminum alloy that does not function as a filler when brazed. The assembled aluminum structure is brazed by heating it and then cooling it in an inert-gas atmosphere such that the filler-material layer of the clad plate flows and forms a fillet joining the hollow structure to the tube along the through hole.