Described herein is an aluminium alloy multi-layered brazing sheet product for brazing in an inert-gas atmosphere without a flux, comprising a core layer made of a 3xxx alloy comprising 0.20-0.75 wt. % Mg, and provided with a covering clad layer comprising 2-5 wt. % Si on one or both sides of said 3xxx alloy core layer and a Al—Si brazing clad layer comprising 7-13 wt. % Si positioned between the 3xxx alloy core layer and the covering clad layer, wherein the covering clad layer has a thickness X.sub.1 and the Al—Si brazing clad layer has a thickness X.sub.2 and wherein X.sub.2≥2X.sub.1. The invention further relates to the use of an aluminium alloy multi-layered brazing sheet product in a fluxfree controlled atmosphere brazing (CAB) operation to produce a heat exchanger apparatus.

A nickel-based brazing foil with a composition consisting essentially of 11 atom %<Cr≤16 atom %, 0 atom %≤Mo≤3.5 atom %, 4 atom %≤B≤5.5 atom %, 11 atom %≤Si≤16 atom %, 0 atom %≤P≤0.5 atom %, 0 atom %≤C≤0.85 atom %, 0 atom %≤Fe≤5 atom %, 0 atom %≤Co≤5 atom %, 0 atom %≤Cu≤2 atom %, 0 atom %≤V≤2 atom %, 0 atom %≤Nb≤2 atom %, incidental impurities of ≤1.0 wt. % and the rest Ni, is provided.

A brazing method for brazing a material without using a flux includes performing brazing in an inert gas atmosphere, in a state in which the material to be brazed is covered with a cover member formed of an upper cover portion covering the whole upper portion of the material to be brazed and side cover portions covering at least some of the side portions of the material to be brazed, with the upper cover portion contacting the upper portion of the material to be brazed, and the material to be brazed and the cover member are held with a heat transmission promoting member formed of an upper heat transmission promoting portion and a lower heat transmission promoting portion, with the upper heat transmission promoting portion contacting the upper cover portion, and with the lower heat transmission promoting portion contacting the lower portion of the material to be brazed.

The invention relates to a multi-layered brazing sheet material comprising of an aluminum core alloy layer provided with a first brazing clad layer material on one or both sides of the aluminum core layer and at least one second brazing clad layer material positioned between the aluminum core alloy layer and the first brazing clad layer material.

An apparatus for manufacturing a heat exchanger for a vehicle has a plurality of cooling panels bonded to each other by pressing a cooling panel module where the plurality of cooling panels are stacked vertically, including: a fixing portion for supporting top and bottom ends of the cooling panel module; and a pair of elastic portions that are provided between the top or bottom end of the cooling panel module and the fixing portion, and are arranged symmetrically based on a top or bottom surface of the cooling panel module to compress the cooling panel module.

Disclosed is a Ni—Cr-based brazing alloy including, on the basis of mass %: 15%<Cr<30%; 3%<P<12%; 0%≤Si<8%; 0.01%<C<0.06%; 0%≤Ti+Zr<0.1%; 0.01%<V<0.1%; 0%≤Al<0.01%; 0.005%<O<0.025%; 0.001%<N<0.050%; 0%≤Nb<0.1%; and the balance being Ni and incidental impurities. Inequality (1): 0.2≤0.24V %/C %≤1.0 is satisfied if the alloy contains no Nb, and Inequality (2): 0.2≤(0.24V %+0.13Nb %)/C %≤1.0 is satisfied if the alloy contains Nb. Also disclosed is an inexpensive Ni—Cr-based brazing alloy containing a trace amount of V for use in the production of stainless steel heat exchangers and other steel articles. The alloy has a low liquidus temperature and high corrosion resistance, and achieves high brazing strength.

A hot-forming die has a heatable lower die and a heatable upper die. The lower die and the upper die have spacer elements to permit flexing. A plate stack including two plate elements is inside the hot-forming die. The plate stack is on the spacer elements in the lower die. The lower die and the upper die are displaced relative to each other when the hot-forming die is closed. The spacer elements of the upper die come into contact with the plate stack. As the closing movement continues, the spacer elements, are displaced into the lower die and the upper die, respectively, and the plate stack is clamped between the lower die and the upper die. The plate stack is then heated by the lower die and the upper die and an internal pressure is applied to an intermediate space between the plate elements by feeding in an active medium.

Described herein is an aluminium alloy multi-layered brazing sheet product for brazing in an inert-gas atmosphere without a flux that includes a core layer made of a 3xxx alloy that includes <0.2 wt.% Mg, and that provides a covering clad layer that includes 2-6 wt.% Si on one or both sides of said 3xxx alloy core layer and a Al—Si brazing clad layer that includes 7-13 wt.% Si positioned between the 3xxx alloy core layer and the covering clad layer, wherein the covering clad layer has a thickness X.sub.1 and the Al—Si brazing clad layer has a thickness X.sub.2 and wherein X.sub.2 ≥ 2X.sub.1. Also described herein is the use of an aluminium alloy multi-layered brazing sheet product in a flux-free controlled atmosphere brazing (CAB) operation to produce a heat exchanger apparatus.

A heat exchanger includes a first manifold, aa second manifold, at least one heat exchange tube segment extending between and fluidly coupling the first manifold and the second manifold, and a fin having a non-linear configuration. A portion of the fin is affixed to an adjacent surface of the at least one heat exchange tube segment via a braze joint. The braze joint has a length, measured parallel to a length of the at least one heat exchange tube segment, less than or equal to 650 micrometers.

A heat transfer unit for a motor vehicle may include a metallic heat transfer block and a base plate. The heat transfer block may include channels that are configured to be flowed through. The base plate may include an outer region and a material bonding region. The base plate may be exposed towards the outside and may be materially bonded to the heat transfer block in the material bonding region. The base plate may be formed out of an aluminium, an aluminium alloy, or a wrought aluminium alloy. The outer region of the base plate may comprise a protective coating produced by anodising at least in regions, and the material bonding region of the base plate may not have a protective coating produced by anodising.