Abstract: Aluminum brazing alloys for assembling aluminum heat exchangers by brazing which consist essentially of 4.5 to 13.5% of Si, from 0.005% to less than 0.1% of Sr and the balance essentially Al and, further, optionally may contain at least one element selected from the group consisting of 0.3 to 3.0% of Mg, 2.3 t0 4.7% of Cu and 9.3 to 10.7% of Zn. The aluminum brazing alloys provide high strength brazed joints with highly refined microstructure and brazing operation can be performed in a good condition without causing any detrimental cavity. Such excellent properties make the brazing alloys especially suited for the fabrication of superhigh pressure heat exchangers.

Abstract: Aluminum brazing alloys for assembling aluminum heat exchangers by brazing which consist essentially of 4.5 to 13.5% of Si, 0.05 to 0.5% of Ca and the balance essentially Al and, additionally may contain Mg in the range of 0.3 to 3.0% or at least Cu component of 2.3 to 4.7% of Cu and 9.3 to 10.7% of Zn. The aluminum brazing alloys have an excellent brazability and provide high strength brazed joints with highly refined microstructure. Such superior properties make the brazing alloys especially suited for the fabrication of superhigh pressure heat exchangers.

Abstract: Fin stock materials adapted for use in superhigh pressure service heat exchanger fabricated by brazing are made of aluminum alloys consisting essentially of, in weight percentages, 0.6 to 1.5% of Mn, 0.1 to 1.0% of Cu, 0.1 to 0.75% of Mg, and 0.05 to less than 0.30% of Si, and the balance being aluminum and incidental impurities, the Fe in said impurities being controlled up to 0.8%. The aluminum alloy fin stock materials contain optionally at least one component selected from the group consisting of 0.05 to 0.25% of Zr, 0.01 to 0.25% of Ti, 0.05 to 0.25% of Cr and 0.01 to 0.25% of V. The fin stock materials have a combination of advantageous properties, particularly a high prevention effect of excessive silicon diffusion of brazing materials into the fins, good strength and formability, whereby give good utility particularly in plate fin heat exchangers for use in superhigh pressure applications.

Abstract: A brazing material is disclosed, particularly suitable for the brazing of fins onto a heat exchanger exposed to high internal pressure, comprised of an Al-Si based alloy wherein the Fe content is limited to not more than 0.15 wt %. The brazing material is suitable for use in the brazing of Mg-containing materials.

Abstract: A brazing method is disclosed which provides superior strength in the brazed joint formed. The brazed structure is subjected to a heat treatment after brazing, which improves the strength of the joint even if Magnesium compounds are employed.