DE2111543A1 - Plated composite body - Google Patents

Description

Clad composite

It is already known that products made of aluminum alloys by brazing in a vacuum, in are superior in many ways. In particular, these are items made by brazing in a vacuum since they do not require the use of a special brazing flux, the corrosion problems are superior can cause and costly cleaning operations required after brazing. Articles made by vacuum brazing also have impact limiting Surfaces that are relatively free by reducing the partial pressure of gaseous products are kept from contaminants, the vacuum environment being the contamination of the surfaces to be joined eliminated by oxides, nitrides or hydrates, usually in varying amounts even in the best brazing ovens can be found that do not have vacuum

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Use environment. The result is that by soldering Aluminum joints produced in a vacuum have increased strength and optimal quality.

Currently, the only two Dutch aluminum alloys that are widely used as core materials in vacuum brazing are alloys 6951 and 3003, and it is well known that these core materials are not entirely satisfactory for the mass production of items such as 2.B. ; they are usually a tea exchanger. In particular, the oiegt! Alloy 6951 (F) excessively durcn 114- ⁰ with a solidus temperature of about 5.56 ^ C (when ° C (IO ⁰ H ¹ F) is brazed at temperatures ilder 615th other hand, the alloy 3003 that oisaer has been used during the vacuum brazing, to flex as much as the alloy 6951 is no tendency, the alloy 3003 (having a solidus temperature of about 64 2 ° C (1130 ⁰ F) is unsuitable, however, in general, for many applications, since they cannot be subjected to any heat treatment. Also for practical design considerations, the alloy 3003 has no tempering ("like hard-

2 soldered ") only a yield point of 422 kg / cm (5000 psi) and is therefore not considered an optimal alloy, e.g. in the manufacture of high-performance heat exchangers is required for motor vehicles.

The alloys currently used to clad the core materials 6,951 and 3003 are generally used fully melted only at temperatures too close to the temperature at which the vacuum brazing would take place to take place naturally, whereby these cladding alloys usually have a relatively wide melting point

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area that is very undesirable. It has also been found that today's cladding alloys do do not allow joints of optimal strength for a number of reasons, including but not limited to because of the great tendency of the silicon present in the cladding material to migrate into the core material, as well as because of the tendency to corrosion in the "hard solder toasting" as a result of the comparatively large inequality between the components of the commercially available materials and the clad or clad alloys.

In the case of the aluminum alloys previously commercially available that are used in vacuum brazing, the presence of iron in the alloy was only accepted as an impurity. It was, however found according to the invention that iron is intentionally added as an alloying element and the addition is regulated can be used to either increase the properties of a core alloy (the parent material of clad Metal) or a cladding alloy.

The invention provides improved aluminum alloys in the form of parent materials of clad metal or of clad alloys or clad layers managed in which iron as a controlled component to improve their quality is used, these alloys are particularly suitable for the production of Articles using vacuum brazing methods. The compositions of such parent and clad materials are metallurgically and chemically the same, so these materials are used to manufacture improved composite Constructions or lamellar structures or layer material such as brazing layer or brazing sheet material can be used to maintain high-quality constructions and with optimum corrosion resistance

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the can. In addition, according to the invention improved mother material increased resistance to sagging at vacuum brazing temperatures, he

can also be treated to bxs exner minimum yield strength of 844 kg / cm (2000 psi) with heat, and has a solidus temperature of about 26 6 ° C (1160 ⁰ F) to 637 ⁰ C (1180 ⁰ F). Because of this improved resistance to deflection at elevated temperatures, the alloy is not only suitable for brazing, but also for other operations such as porcelain enamelling, in which the core or parent material of clad metal can be clad with relatively pure aluminum.

The inventive improved plating is completely liquid at a temperature of about 579 ° C (1075 ⁰ F) and has a narrow melting point range, which - does not exceed 1.1 ° C (3O ⁰ F).

Further details, purposes of use and advantages of the invention will become apparent from the following description their embodiments in conjunction with the accompanying drawing.

The attached drawing shows exemplary embodiments of objects with the alloys according to the invention as well as the representation of sag profiles of these alloys compared to the commercially available alloys. Show in it:

1 is a partial perspective view of an example indicated which is suitable for vacuum brazing Heat exchanger using the alloys improved according to the invention;

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Fig. 2 is a schematic diagram of the sagging profiles of sample strips, made using aluminum alloys according to embodiments of the invention are made, compared to the sag profiles of the 6 951 alloys and 3003 test strips produced, wherein the slack by heating the strips in a Vacuum brazing furnace is created;

Figure 3 is a perspective view with some parts in cross-section and other parts broken away are ,, where an embodiment of a composite or Sehichtmaterials. is shown of what both the core or mother material and the cladding overlay on a surface of the mother material, made from improved aluminum alloys according to the teachings of the invention are and

Fig. * Fc a view similar to Fig. 3 of an improved Mother material, the opposite of each other Surfaces with an improved plating layer is provided.

Items such as heat exchangers ,, are made of Äluminiumlegierungen like, have a greater structural integrity when they are produced using the Vakuumhartlötmethodeix _s and this fact has already been mentioned. A typical vacuum brazed heat exchanger in the form of an automotive radiator is shown in Figure 1 of the drawings. The cooler 10 has components such as, for example, its tank 11A, which is made from the mother material or composite material according to the invention. The lower section of the

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-D-

Tanks IiA, ie the head part HB, the inner surfaces of the oppositely arranged support plates 12 and a large part of the exposed surfaces of the flattened tubular parts 13 can expediently be clad with the plating material improved according to the invention, so that the cooler can be assembled in a manner known per se and attached to a associated holder held together in position and then at a suitable brazing temperature of 601 ⁰ C, for example (1115 ^Q F), which is controlled within plus or minus 8 C C15 F), can be hard-dissolved in a vacuum.

The core alloy or the mother material according to the present invention has a solidus temperature of about 626 ° C C1160 ⁰ F) to 637 ° C ClISO ⁰ F), while the cladding alloy or cladding is completely liquid at about 579 ° C C10-5 ° F) and a narrow melting point αά ± _χ of -1, .1 ° CC 3G> ° F) does not exceed. After the cooler 10, held on its holder in the assembled state, is brought into a commercially available brazing furnace of known construction which is heated to a suitable brazing temperature, preferably 3.9 C 25 ° F) above the liquidus of the cladding material and at least 3.9 ° C C25 ° F) below the solidus point of the core material, its components are brazed together as a unit.

The following examples show core alloys according to the invention or mother materials with the listed elements.

Mother material example 1 Element. Quantity (percentages by weight

Magnesium about 0.3 - 0 _s 6%

Silicon about 0.2 - 0 * 5%

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Element amount (percent by weight)

manganese up to about 0.7% iron about 0.2 - 0.8% chrome up to about 0.6% other each less than 0.05% and ins total less than 0.15 % aluminum rest

Mother material example 2 Element amount (percent by weight)

Magnesium about 0.3-0.6%

Silicon about 0.2-0.5 %

Manganese about 0.3-0.7%

Iron about 0.2-0.8 %

Chromium up to about 0.6%

others each less than 0.05% and total less than 0.15%

Aluminum rest

Mother material example 3 Element amount (percent by weight)

Magnesium about 0.3-0.6%

Silicon about 0.2-0.5%

Manganese up to about 0.7%

Iron about 0.2-0.8%

Titanium about 0.01 - 0.10%

Chromium up to about 0.6%

others each less than 0.05% and total less than 0.15%

Aluminum rest

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Mother material example

element Quantity (percent by weight) magnesium about 0.3-0.6% Silicon about 0.2 - 0.5% manganese up to about 0.3% iron about 0.2 - 0.5% chrome about 0.1-0.6% other each less than 0.05% and ins total less than 0.15% aluminum rest

Mother material example 5

element Quantity (percent by weight) magnesium about 0.3-0.6% Silicon about 0.2 - 0.5% manganese about 0.3-0.7% iron about 0.2 - 0.5% chrome about 0.1-0.6% other each less than 0 _t 05% and ins total less than 0.15% aluminum rest

As already mentioned, iron is often present in commercial aluminum alloys and as an impurity in Purchase taken. However, it has been found through extensive experiments that iron can be used as an aid to lowering the silicon penetration in the core of the molten zen cladding is effective and therefore to maintain mother material with the desired physical properties

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shafts can be used. As from the above Examples of core alloys or mother materials, iron is preferably controlled, see above that it made up about 0.2-0.8 percent by weight of the alloy. If chromium is also present, then the Iron content can be reduced to about 0.2-0.5%.

Magnesium is provided in the Kerr alloy in order to ensure that the desired level of mechanical properties is achieved while adding manganese is used to ensure that the core material is at the brazing temperature has an optimal sag resistance.

Titanium can also be introduced in controlled amounts, especially 0.01-0.10%, as in Example No. 3 shown to aid in kernel size regulation.

As already mentioned, are used in vacuum brazing commercially available core materials or nut materials, the alloys 6951 and 3003. The alloy 6951 is for brazing at about 5 9 3 ° C (1100 ⁰ F) is generally unusable because it sags excessively, it can ier with the PlattierIegierungen be used according to the invention for brazing at lower temperatures or with appropriate support.

Fig. 2 shows the sag profiles of five exemplary Test strips or samples that are used as strips A, B, C, D and E are designated, while the constituent elements and their weight percentages are given in the following Table are shown.

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sample mm (0 (in.) A. 0.5461 (0 , 0215) β 0.5588 (0 , 022) C. 0.6096 (0 , 024) D. 0.55 88 (0 , 022) E. 0.5588 , 022)

thickness

% Si ^; is Fe% Mn % Hg,% other% Al

0.22 0.55 0.30 0.30 less than 0.15 remainder 0.37 0.75 0.01 0.56 less than 0.15 remainder. 0.42 0.67 0.48 0.59 less as 0.15 remainder Commercially available alloy 3003
Commercially available alloy ei 951

Each of these AE coupons were 199.771 mm (7.865 in.) Long, 19.05 now (0.750 in.) Wide, and had a thickness as shown in the table above. The samples were supported by a support plate 16 and a horizontal support or pin 17 with approximately 275,971 minutes (1.86 5 in.) At one end portion of each sample being held horizontally on the supports 16 and 17 by a support plate 18 The remaining 15 protruded 2.4 mm (6 in.) past the horizontal pin 17 like a cantilever. The samples AD were then subjected to a vacuum treatment and heated to a temperature of 606.5 ⁰ C (1125 ° F), after which each sample SiCN A Dxs D -. As shown in Figure 2 - durchbog due to heating.

The deflection profile for the strip E represents a deflection of this strip 93 at 5 ° C (1100 ⁰ F) Darj when subjected to a similar vacuum treatment as the strips AD. The temperature 5 93 ° C (110Q ⁰ F) was selected as the maximum temperature for alloy 6 951, which is all heat exchangers made from brazing sheet using the parent material or core alloy 6951 when brazing at 5 93 ° C (1100 ⁰ F), arrangements acceptable deflection exhibited, but only at somewhat higher temperatures of 595.5 ° C (1105 F ⁰⁾ - 593 ° C (1110 ⁰ F), these devices showed an edge line deflection, as commercially comparatively un-

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was judged usable. The deflection at 593 ° C (1100 F) for Sample E using the alloy 6 951 is therefore used as a basis for a comparison of the exemplary mother materials according to the present Invention and the alloy 3003 with the alloy 6,951 considered.

From Fig. 3 it can be seen that the inventive Mother material alloys "A, B and C in their resistance against deflection are superior to alloy E and at least as good as alloy D, the alloys D and E are commercial alloys 3003 and 6 951, respectively. The resistance to deflection is at This is important for brazed objects, as it is extremely difficult if there is excessive deflection during brazing is to keep the manufacturing tolerances and get good joints, even if complicated and expensive Brackets are used.

Although alloy 3003 shows good resistance to deflection, it cannot be treated with heat

2 become; it has a yield strength of only 422 kg / cm (6000 psi) with no stone pitting. The alloys according to the invention as the mother materials shown by samples A to C can be treated with heat, ie they can be aged or tempered in order to

limit of at least 814 kg / cm (12000 psi).

It must therefore be emphasized that the improved core alloys or mother materials according to the invention show a resistance to deflection that is superior to the commercially available alloy 6 951, so that these alloys are particularly suitable for vacuum brazing. The mother materials according to the invention can also be subjected to a heat treatment,

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so that they have a yield strength that is at least twice the flow strength of alloy 3003, which is the other commercially available aluminum alloy commonly used in vacuum brazing.

The invention also provides cladding or cladding alloys particularly suitable for use in conjunction with the parent materials, having essentially the compositions noted above, and such cladding alloys having superior properties when used with these or other parent materials which are vacuum brazed should. The Plattierauflagen according to the invention melt in the narrow range of 1.1 (30 F) does not exceed C, each (F 1075 ⁰⁾ is completely liquid at about 579 ° C. The inventive nut materials each have a solidus temperature of about 626 ° C (1160 ⁰ F) to 637 ° C (1180 ⁰ F), so that oei their combination with a Plattierauflage with a liquid point of about 579 C (1075 F) optimal results with sufficient Tolerances for customary processes are achievable.

The following examples show plating layers or alloy materials according to the invention with the elements listed.

Clad alloy example 1 Element amount (in percent by weight)

Silicon about 11.0 - 14.5 &

Iron about 0.2 - 1.2%

Chromium up to about 0.25%

Magnesium about 0.2 - 1.0%

others each less than 0.05% and total

less than 0.15% aluminum balance

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Clad Alloy Example 2 Element Amount (in percent by weight)

Silicon about 11.0 - 14.5%

Iron about 0.2 - 1.2%

Chromium up to about 0.25%

Magnesium about 0.2-1.0%

Manganese up to about 0.3%

others each less than 0.05% and total

less than 0.15%

Aluminum rest

Clad Alloy Example 3 Element Amount (in percent by weight)

Silicon about 11.0 - 14.5%

Iron about 0.2 - 1.2%

Chromium about 0.10 - 0.20%

Magnesium about 0.2 - 1.0%

Manganese up to about 0.3%

others each less than 0.05 and total

less than 0.15%

Aluminum rest

Clad Alloy Example 4 Element Amount (in percent by weight)

Silicon about 11.0 - 14.5%

Iron about 0.2 - 1.2%

Chromium up to about 0.25%

Magnesium about 0.2 - 1.0%

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Element amount (in percent by weight)

Copper Dis about 0.3 I.

others each less than 0.05 and total

less than 0.15% aluminum balance

Clad Alloy Example 5 Element Amount (in percent by weight)

Silicon about 11.0 - m, 5%

Iron about 0.2 - 1.2%

Chromium ois about 0.25%

Magnesium about 0.2 - 1.0%

Copper about 0.1-0.3%

Zinc about 0.15 - 0.5%

others each less than 0.05 and total

less than 0.15%

Aluminum rest

As in the case of the hatch materials according to the invention Iron instead of treating it as an impurity in the aluminum alloy (which was previously the case with the plating layers was the case), introduced as a controlled element. It has been found that iron in amounts of at least 0.6 and up to about 1.2 weight percent is particularly effective in controlling the viscosity, and hence the flow, of the cladding material in connection with maintaining a narrow melting range of the alloy.

It should also be noted that chromium is a deliberately chosen one Alloy element is necessary for solderability and

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Corrosion resistance of the plating contributes, though it is used within the range up to about 0.25% of the composition. In any case, it was found da / ό chromium in the controlled range of 0.10 0.20 Weight percent gives the best results. For some uses, up to about 0.3 percent by weight Hangan as an intentionally chosen alloy element with or onne cnrora, for others - uis 0.3 percent by weight Copper ozw, "about 1.0-0.3 percent by weight Copper plus about 0.15-0.5 percent by weight of zinc at ^ egeDen, see the plating examples 2, 3, 4 and 5. Magnesium has been added to control the mechanical properties of the cladding alloy, however, the amount is limited to improve liability. Copper and zinc in the specified Quantities are used to control wettability and galvanic potential.

The amount of silicon in the clad alloy is between 11 -ο and 14.5's of the total weight of the composition , ^ precisely controlled. The amount of silicon is important because is known, there is a silicon diffusion or migration from the plating in the parent material or the Aernlegierun ^ scikidlicn is. The xieraosetzung des SiIiciuiiis in over plating has the / effect, caß at iiypoeutektisci.en silicon alloys the liquidus temperature increases. The higher the liquidus temperature, the lower the flow at a given brazing alloy temperature.

This invention has been found because it was added of at least about 0.3 percent by weight manganese in the core vlie tendency is this silicon diffusion in the parent plant to withstand fabric, whereby a using both the Hutterwerkes and the plating after -, - ar i-rfinaung formed object or a resulting ^] :: "erence construction of optimal properties arises,

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-ass -

which are particularly compatible with vacuum brazing. By precisely controlling the amount of silicon to achieve the desired melting range of the cladding alloy and by using manganese in the mother material Thus, according to the invention, an improved brazing material was obtained to promote the control of silicon diffusion.

The mother material and the cladding alloys according to the invention can be made and in any shape may be used, including those known in the art, either with each other or with commercially available materials or alloys. The core alloys can be used in any suitable form can be used, e.g. as tubes, rods, plates or foils etc., while the cladding alloys can be made as separate items such as o-rings, strips, washers, wire, etc. that are placed between a pair of parts to be joined by brazing or mechanically held between these parts will.

Preferably, the clad materials or alloys are each in the form of a clad in sheet form on an article such as a composite braze sheet material or composite sheet material 20 with a plurality of layers as shown in Fig.3. For example, the layered workpiece has a core alloy or a mother material 21 with constituent elements? as in any of the above examples, this workpiece being made of layered material has a clad alloy 22 on each side. The alloy 22 can essentially be used as constituents have the elements listed above.

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A brazing plate can also be provided essentially as in FIG. 4 of the drawing and generally with be provided with the reference numeral 20A. The brazing plate 20A can consist of core material or mother material 21, which is made from the components outlined above as elements and each with a panel or cladding 22 may be provided on both sides, which also includes components such as the elements outlined above .

The thickness of the sheet on a given sheet or multilayer board provided plating of the plate 20 or 20A varies depending on the total thickness of the multilayer

ten plate. For manufacturing multilayer boards in particular for use in vacuum brazing with a total multilayer body thickness of 0.6096 mm (0.024 in.) or less, the plating thickness on one side of the body can be about 10% of the total thickness; for laminated bodies from 0.635 to 1.6002 mm (0.025 to 0.063 in.) the cladding thickness in one side can be 8% of the total thickness of the laminate, and for laminates with a total thickness of 1.6256 mm (0.064 in.) and greater the cladding thickness on one side can be about 4% of the total laminated body thickness. The percentages above the plating thickness are typical, regardless of whether one or both sides of the plate or the Laminated body are plated.

The ratio of the plating to the thickness of the core can be changed according to the joining conditions, without significantly changing the strength of the end product. From an in-depth comparison of the components of the Core and the cladding can also be seen that the combination of the cladding and the core is metallurgically and chemically similar, resulting in a system that has excellent corrosion resistance

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has consistency.

The composite construction or the composite body or multilayer body 20 or 20A, which is characterized by a core alloy according to the invention or a cladding alloy according to the present teaching, also withstands the migration of silicon from the cladding or cladding into the core or mother material to a greater extent than any Previously decanted with heat treatable brazing composite body as a layer material. The composite structure also has an unexpectedly high resistance to deflection during preheating for vacuum brazing and can be used to maintain flow strengths
Heat treated.

yield strengths of 844 kg / cm ² (12,000 psi)

The composite structure according to the invention made of sliced material also exhibits the largest range of temperature between the plating liquidus point and the mother material solidus point that has ever been known in any heat treatable brazing alloy composite materials. In particular, and as mentioned earlier, the plating at about 579 ° C (1075 ⁰ F) - 3 ° C (5 ° F) completely liquid, while the solidus temperature of the core material is about 626 ° C (1160 ⁰ F) to 637 ° C (1180 ⁰ F), (F ⁰ 80) is provided whereby a minimum temperature range of 26.7 ° C. This large temperature range between the solidus point of the core alloy and the liquidus point of the cladding alloy enables commercially available vacuum brazing furnaces to be provided with less complicated and consequently relatively cheap temperature regulators.

In this inventive Ausfünrungsuebeispiel a

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Heat exchanger 10 shown using a improved core alloy and an improved cladding alloy prepared according to the teaching of the invention became; however, it should be noted that any suitable product made from the unique alloys Manufactured according to the teaching of the invention can be.

Objects in the form of plates or multilayer sheets 20 and 20A were shown in FIGS. 3 and 4, respectively, as only Examples of composite structures using the core and clad alloys, respectively shown according to the invention. It is clear, however, that compound constructions of every other form, shape etc. can be produced using the alloys of the present invention.

While only a few embodiments of the invention and some methods of making it are described here and illustrated, it will be understood that the invention may take various forms in other ways and can be used in practice within the scope of the following claims.

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Claims (14)

Claims Clad composite body made of an aluminum alloy core and a cladding alloy adhering to it, characterized in that the cladding is composed of an alloy containing 11 IM, 5 percent by weight Si, 0.2-1.2 percent by weight Fe, to 0.25 percent by weight Cr, to 0.3 weight percent Mn, and 0.2 - 1.0 weight percent comprising pig, the balance being aluminum and incidental impurities, and the alloy has a narrow melting range, which - does not exceed 1.1 ° C (30 ⁰ F), and a Has a liquidus temperature point of approximately 579 ° C (1075 ⁰ F). 2. Composite body according to claim 1, characterized in that the iron content in the cladding alloy is at least 0.6 percent by weight. 3. Composite body according to claim 1, characterized in that the cladding alloy is about 0.3 percent by weight manganese contains. 4. Composite body according to claim 1, characterized in that that the chromium content of the cladding alloy is 0.10 - 0.20 • percent by weight. 1 09 8 A 0/1200 5. Composite body according to claim 1, characterized in that the cladding alloy is up to 0.3 percent by weight Contains copper. 6. Composite body according to claim 1, characterized in that the cladding alloy 0.1-0.3 percent by weight Contains copper and 0.15-0.5 percent by weight zinc. 7. Composite body according to one of claims 1-6, characterized in that the cladding is attached to a core which is composed of an alloy consisting of 0.3-0.6 percent by weight Mg, 0.2-0.5 percent by weight Si, up to 0.6 percent by weight Cr, up to 0.7 percent by weight Mn and 0.2-0.8 percent by weight Fe, with the remainder made up of aluminum and minor impurities consists. 8. The composite body according to claim 7, characterized in that the manganese content of the core alloy is at least 0.3 Weight percent is. 9. Composite body according to claim 7, characterized in that that the core alloy contains 0.01-0.10 percent by weight titanium. 10. Composite body according to claim 7, characterized in that the core alloy consists of 0.3-0.7 percent by weight Mn, 109840/1200 0.3-0.6 percent by weight Mg, 0.2-0.5 percent by weight Si, 0.1-0.6 percent by weight Cr and 0.2-0.5 percent by weight Fe, with the remainder consisting of aluminum and minor impurities. 11. Composite body according to one of claims 7-10, characterized in that the core alloy has a solidus temperature point of 6 26 ° C (1160 ⁰ F) to 6 37 ° C (1180 ⁰ F). 12. Composite body according to AnSpI ¹ UCh 11, characterized in that the core alloy has a minimum yield strength of 844 k |
can be traded. ο
strength of 844 kg / cm (12000 psi) with heat 13. Composite body according to one of claims 1-6, characterized in that the cladding is on a core which is composed of a 6951 alloy. 14. Composite body according to one of the preceding claims, characterized by the shape of a multilayer board. 109840/1200