JP2801095B2 - Method for manufacturing aluminum honeycomb structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an aluminum honeycomb structure used for floor materials and wall materials of railway cars and aircrafts.

[0002]

2. Description of the Related Art A honeycomb core made of an aluminum brazing sheet having a thickness of about 0.2 to 0.3 mm is generally used as a conventional aluminum honeycomb body of this type, and is vacuum brazed at a brazing temperature of 590 to 600.degree. Has been manufactured.

[0003]

However, in the conventional manufacturing method, the brazing material of the honeycomb core erodes into the core material at the time of brazing, resulting in a decrease in strength, and in extreme cases, buckling occurs. There is a problem.

[0004] In particular, when an Al-Mg-Si-based material such as AA6951 is used as the brazing sheet of the honeycomb core, the strength after brazing can be improved because this material is a heat-treated alloy. Although,
It is susceptible to erosion of brazing material and has a high risk of buckling.

The present invention has been made in view of the above-mentioned problems, and it is intended to prevent buckling of a honeycomb core at the time of brazing, to obtain good joining, and to improve the bonding of 6951 material or the like.
An object of the present invention is to provide a method for manufacturing an aluminum honeycomb structure which can prevent buckling even with a brazing sheet using a Mg-Si-based core material.

[0006]

According to a method of manufacturing an aluminum honeycomb structure according to the present invention, a honeycomb core made of aluminum or an aluminum alloy is sandwiched between upper and lower plates.
In a method for manufacturing an aluminum honeycomb structure configured to arrange a side plate provided with holes between edges of the upper and lower surface plates and surround the honeycomb core with the side plates, the side plate has an area and a hole of the holes. 1/20 ratio to total area including
Wherein the honeycomb core and the upper and lower plates are 7 to 13% by weight of Si and 0.5 to 2.0%.
It is characterized by being assembled by vacuum brazing at a temperature of 560 to 575 ° C. using an aluminum alloy brazing material containing Mg by weight.

The ratio of the area of the holes in the side plates to the total area is the ratio of the total area of the holes to the total surface area of the side plates, and the total surface area of the side plates is the area surrounding the honeycomb core between the upper and lower plates. This ratio is the ratio of the total area of the holes in the side plate to the total area of the region sandwiched between the upper and lower plates.

[0008]

The erosion of the brazing material into the core material increases sharply as the brazing temperature increases. Therefore, by lowering the brazing temperature, erosion of the brazing material into the core material can be suppressed.

According to the present invention, in order to prevent buckling during brazing of a honeycomb structure, brazing is performed at a low temperature.
This prevents erosion of the brazing material into the core material. Specifically, brazing at a low temperature is made possible by using a brazing material that can be melted at a low temperature and making the honeycomb core a semi-closed structure with side plates.

Next, the method of the present invention will be described in more detail.

[0011] Aluminum vacuum brazing is usually performed using Mg.
Using an Al-Si brazing material containing 10 ⁴ to 10 ⁶
Usually, heating is performed at 590 to 600 ° C. under a Torr vacuum condition, but almost all of the Mg in the brazing material is evaporated and discharged at a portion directly exposed to the furnace atmosphere. However, since the present invention has a semi-closed structure, Mg is difficult to be discharged from the inside to the outside, and most of the Mg remains in the reverse of the outside.

The Al-Si-Mg based alloy has a eutectic point at 555 ° C., while the Al—Si binary alloy has a eutectic point of 57 ° C.
7 ° C. That is, the Al-Si based brazing material is made of Mg.
The melting temperature changes depending on the presence or absence of Mg, and the Mg-containing brazing material melts at a lower temperature than those containing no Mg.

In the present invention, attention is paid to lowering the melting temperature of the Al-Si-Mg system, and the buckling is prevented by enabling brazing at a lower temperature than conventional brazing methods.

Therefore, in the present invention, a brazing material containing 7 to 13% by weight of Si and 0.5 to 2.0% by weight of Mg is used.

The outer peripheral portion between the upper and lower plates is surrounded by side plates provided with holes. The size and number of the holes in the side plate are set so that the ratio of the area of the hole to the total area of the side plate including the hole is 1/2000 to 1/100.

Then, the honeycomb core and the upper and lower face plates are assembled by heating to a temperature of 560 to 575 ° C. in a vacuum and brazing.

The reasons for limiting the above conditions will be described below. Composition of brazing material Si of brazing material is an essential component as a brazing material that melts and flows at a low melting point. When the content of Si is less than 7% by weight, the liquidus temperature is high and the fluidity is poor, while the content of Si is 13% by weight. %, It becomes hypereutectic and the fluidity is also poor. Therefore, S
The i content is 7-13% by weight.

Mg is an essential component as a getter material in vacuum brazing, and the lower limit must be 0.5% by weight in order to obtain a sufficient action as the gator material.
On the other hand, if the Mg content exceeds 2.0% by weight, the brazing properties inside the semi-closed structure due to the side plates deteriorate. That is, Mg is liable to evaporate during heating by vacuum brazing and exerts a getter function. However, if Mg remains, its oxidizability is strong, so that surface oxidation proceeds and hinders brazing properties. The above Mg upper limit of 2.0% by weight corresponds to an amount at which the influence of surface oxidation due to the residual Mg becomes stronger. For this reason, Mg
The content is 0.5 to 2.0% by weight. Side plate In the present invention, the honeycomb core disposed between the upper and lower plates is surrounded by a side plate provided with holes. This is for adjusting the vacuum evacuation from the space surrounded by the side plates and adjusting the getter function and the residual amount by Mg evaporation to appropriate values.

When the ratio of the area of the hole in the side plate to the total area of the side plate including the hole is smaller than 1/2000, the area of the hole is small, and the vacuum exhaust from the inside surrounded by the side plate becomes too small. . For this reason, a sufficient getter function by Mg evaporation cannot be obtained, and the internal brazing property deteriorates.
On the other hand, if the ratio exceeds 1/200, the total area of the holes becomes too large, and the evacuation becomes too large. For this reason, Mg evaporation of the brazing material and discharge to the outside also increase, and M
Since the residual amount of g decreases, the effect of lowering the melting point due to the inclusion of Mg cannot be sufficiently obtained. Therefore, the ratio of the hole area of the side plate to the total area is 1/2000 to 1/200. If the brazing temperature is lower than 560 ° C., a sufficient amount of Al—Si—Mg eutectic melting cannot be ensured even if a sufficient amount of Mg remains, so that sufficient fillet formation cannot be obtained. On the other hand, when the brazing temperature exceeds 575 ° C., the erosion of the brazing material into the core material increases, and the risk of buckling increases.

It should be noted that various types of side plates can be used for shielding the outer peripheral portion. However, it is necessary that the material does not melt during brazing at 560 to 575 ° C. and that a gas that hinders the vacuum atmosphere is not generated, and that the material is not brazed to the honeycomb core body. . For example, a plate made of stainless steel or steel can be used.

[0021]

Next, an embodiment of the present invention will be described.

Using 6951 material as a core material, a brazing material shown in Table 1 below was clad on one surface and both surfaces at a cladding ratio of 10%, respectively, and had a thickness of 1.0 mm (upper and lower plates) and 0.2 m, respectively.
An m (honeycomb core) brazing sheet was produced.

The manufacturing method is 50 mm for both the brazing material and the core material.
A clad material having a predetermined clad ratio was produced by casting in a mold having a thickness of 145 mm (width) x 240 mm (length), and a soaking treatment and hot rolling.

After hot rolling, cold rolling, intermediate annealing, and cold rolling are performed to obtain a thickness of 1.0 mm (one side of 1 mm).
Each H14 heat-treated material having a thickness of 0.2 mm (10% clad ratio on both sides) and a thickness of 0.2 mm (0% clad ratio) was manufactured.

As shown in FIGS. 1 to 3, a honeycomb structure comprising the upper and lower face plates 1 and 2 and the honeycomb core 5 manufactured as described above and the separately prepared 1050 side plate 3 is formed by brazing. Assembled. FIG. 1 is a plan view of this honeycomb structure, FIG. 2 is a side view, and FIG. 3 is a schematic view showing a honeycomb core. The side plate 3 has a hole 4 and the upper and lower plates 1, 2
Are arranged so as to surround the honeycomb core 5 from all sides. The dimensions (unit: mm) of each member are as described in the figure. However, the thickness of the upper and lower plates 1 and 2 was 1.0 mm as described above, and the thickness of the honeycomb core 5 was 0.2 mm.
mm.

The brazing was performed by heating to a temperature shown in Table 1 below under the condition of a vacuum degree of 8 × 10 ⁻⁵ Torr. The ratio between the holes 4 and the total area of the side plates was adjusted by changing the number of holes 4 formed by perforating the 1050 material side plate 3.

Then, the state of brazing was examined by visual inspection of the appearance after brazing, and the occurrence of buckling was examined and determined by measuring the dimensions.

However, in the brazing conditions, ○ indicates the case where the brazing fillet is uniform and good, △ indicates the case where the brazing fillet is not uniform, and x indicates the case where the brazing fillet is hardly formed. The buckling is indicated by ○ when the decrease in height between the upper and lower plates is less than 1.0 mm, and when X is when the decrease in height between the upper and lower plates is 1.0 mm or more.

As is clear from this table, in Examples 1 to 8 of the present invention, the brazing condition was extremely excellent and no buckling occurred, whereas in Comparative Examples 1 to 6, Either brazing condition or buckling was inferior.

[0030]

[Table 1]

[0031]

According to the present invention, the honeycomb core is surrounded by perforated side plates and the composition of the brazing material, the brazing temperature and the area ratio of the holes are appropriately set, so that the erosion of the brazing material is prevented. Buckling of the honeycomb core at the time of attachment can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view of a honeycomb core structure.

FIG. 2 is a side view of the same.

FIG. 3 is a schematic view showing a honeycomb core.

[Explanation of symbols]

 1, 2; upper and lower plate 3; side plate 4; hole 5; honeycomb core

Claims (2)

(57) [Claims] 1. A honeycomb core made of aluminum or an aluminum alloy is sandwiched between upper and lower plates, and a side plate provided with holes is arranged between edges of the upper and lower plates so that the honeycomb core is surrounded by the side plates. In the method for manufacturing an aluminum honeycomb structure, the side plate has a ratio of the area of the hole to the total area including the hole of 1/2000 to 1/100.
And the honeycomb core and the upper and lower face plates are
560 to 57% by using an aluminum alloy brazing material containing 0.5% by weight of Si and 0.5% to 2.0% by weight of Mg.
A method for producing an aluminum honeycomb structure, comprising assembling by vacuum brazing at a temperature of 5 ° C. 2. The honeycomb core and upper and lower face plates are formed of a brazing sheet, and the core material thereof is 0.2
To 0.8 wt% Mg, 0.2 to 0.8 wt% S
2. The method for manufacturing an aluminum honeycomb structure according to claim 1, comprising an aluminum alloy containing i and 0.5% by weight or less of Cu. 3.