JPH0698480B2 - Manufacturing method of composite brazing member - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is a composite brazing material that is lightweight and has a high cooling effect, and is suitable for use as, for example, a reflection mirror of a carbon dioxide gas laser or an inner wall material of a vacuum furnace. The present invention relates to a method for manufacturing a mounting member.

[Prior Art] Conventionally, for example, as a reflection mirror of carbon dioxide gas, in general, one made of pure Cu whose surface is mirror-finished, or Au
It is known to be plated with pure Cu.

However, in these pure Cu reflecting mirrors, when the laser irradiation time becomes long, not only the metal or non-metal vapor generated from the processed material adheres to the surface, but the reflectance decreases, Accidents have occurred, such as laser energy being absorbed and melted, causing damage to the reflector.

In order to prevent such accidents, it is necessary to regularly remove the deposits on the surface, but the
Since Cu or Au plating is very soft, it is easy to damage the mirror surface or plating surface when wiping it off, and as a result, the reflection characteristics are impaired.

For these reasons, in recent years, it has been established that hard pure Mo or pure W is used instead of pure Cu as a material for a carbon dioxide laser reflecting mirror. In particular, as the reflection mirror made of pure Mo or pure W, a single crystal or a polycrystal of fine crystal grains is easily obtained by polishing a surface having a uniform reflectance, It has less adhesion and exhibits excellent performance.

[Problems to be solved by the invention]

On the other hand, the carbon dioxide laser device is installed not only on the ground equipment but also on the space station.
Along with this, it is strongly desired to reduce the weight of the reflector made of pure Mo or pure W having a large specific gravity (heavy).

[Means for solving problems]

Therefore, from the above-mentioned viewpoints, the present inventors have made a pure Mo or pure W member such as a reflection mirror of a carbon dioxide gas laser and an inner wall material of a vacuum furnace, and also a heavy Mo alloy or W alloy. As a result of focusing on the member and conducting research to reduce the weight, a part of the heavy member composed of pure Mo, Mo alloy, pure W, or W alloy was used as a light material. do it was replaced with (small specific gravity) of pure Si, but will be much lighter, the specific gravity of pure Mo and pure W is, whereas respectively 10.2 g / cm ³ and 19.3 g / cm ³ , That of pure Si is 2.3 g / cm ³ , and that of pure Mo and pure W have a coefficient of thermal expansion of 5.1 × 10 ⁻⁶ / ° C. and 4.5 × 10 ⁻⁶ / ° C., respectively. as is 2.5 × 10 ^-6 / ℃, since the different in characteristics at various points from these heavy materials and light-weight material, brazing these two members at a high joining strength However, it was impossible to reduce the weight, but a Cu layer having an average layer thickness of 0.01 to 50 μm was preferably formed on each of the brazing surfaces of these members, preferably by the ion plating method. In the state of being fixedly formed by the above method, vacuum brazing using a brazing material made of an Al alloy containing Si: 0.1 to 14% by weight, and preferably vacuum brazing at a temperature of 600 to 720 ° C. They have found that they can be joined firmly and a composite brazing member brazed with high joining strength can be obtained.

The present invention has been made based on the above findings, and comprises a brazing surface of a heavy member made of any one of pure Mo, Mo alloy, pure W, and W alloy, and pure Si. An average layer thickness of 0.01 on each of the brazing surfaces of the light material
A Cu layer of ~ 50 μm is fixedly formed, and then both these members are
It is characterized by a method for producing a composite brazing member, which comprises vacuum brazing using a brazing material made of an Al alloy containing Si: 0.1 to 14% by weight.

In the method of the present invention, the average layer thickness of the Cu layer is 0.01
The reason for limiting the thickness to 50 μm is that if the average layer thickness is less than 0.01 μm, the wettability with the brazing material is insufficient and the desired strong joint strength cannot be secured, while the average layer thickness exceeds 50 μm. In addition, internal strain remains when the Cu layer is formed, causing not only peeling in the Cu layer during brazing, but also the Cu concentration in the brazing material is high especially near the brazing surface of the member. The reason for this is that the brazing strength will decrease as a result. Similarly, regarding the Si content of the brazing material, if the Si content is less than 0.1% by weight, brazing on the heavy member side in particular Insufficient formation of the silicide layer formed on the joint surface makes it impossible to secure sufficient joint strength, and the erosion on the braze joint surface of the lightweight member made of pure Si becomes severe. Exceeds 14% by weight If, then brazed surface embrittlement, since the peeling easily occurs in the junction when the thermal strain in the composite brazing member occurs, the content of 0.1
-14% by weight.

〔Example〕

Next, the method of the present invention will be specifically described by way of Examples.

As a heavy member, a thin circular plate having the composition shown in Table 1 and having dimensions of diameter: 100 mm × thickness: 2 mm is prepared. As a light member, purity: 99.999% pure Si is used.
Prepare a disk with a diameter of 100 mm and a thickness of 18 mm, and then use it as the brazing surface for these members. On the side surface, using an ion plating apparatus, under normal conditions, after ion cleaning, Cu layers each having an average layer thickness shown in Table 1 were fixedly formed, and subsequently,
Similarly, a brazing filler metal having a composition of 0.3 mm and a thickness of 0.3 mm is sandwiched between the brazing surfaces of both members, fixed with a scissor jig, and the heavy member is placed on the lower side. , Normal condition, ie pressure: 1 × 10 ^-4 torr in vacuum, temperature: 650 ℃
Inventive methods 1 to 4 and comparative methods 1 to 4 were carried out by performing vacuum brazing under the condition of holding for 15 minutes.

Comparative methods 1 to 4 are the average layer thickness of Cu and Si of the brazing material.
Any of the contents (marked with * in Table 1) is outside the scope of the present invention.

Next, the shear strength of the joint surface of the composite brazing members obtained by the methods 1 to 4 of the present invention and the comparative methods 1 to 4 was measured using a universal testing machine to evaluate the joint strength. The measurement results are shown in Table 1.

〔The invention's effect〕

From the results shown in Table 1, all of the composite brazing members produced by the methods 1 to 4 of the present invention show strong bonding strength, while the average layer thickness of the Cu layer and the brazing material It is clear that in Comparative Methods 1 to 4 in which any one of the Si contents is out of the range of the present invention, none of them shows sufficient bonding strength.

As described above, according to the method of the present invention, pure Mo, Mo alloy, which has been considered to be extremely difficult to perform brazing and joining,
Since a heavy member made of either pure W or W alloy and a light member made of pure Si can be brazed with a strong joint strength, part of the heavy member is made of the light member. It becomes possible to replace with, and it becomes possible to manufacture a composite brazing member that is lighter than that, and pure Si that constitutes the light member is made hard to have the same excellent heat resistance as the heavy member. Since it has conductivity, it has industrially useful effects such as excellent performance over a long period of time when it is used as a reflection mirror for a carbon dioxide laser or an inner wall material of a vacuum furnace. .

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Claims (1)

[Claims] 1. A brazing surface of a heavy member made of pure Mo, Mo alloy, pure W, or W alloy, and pure
A Cu layer with an average layer thickness of 0.01 to 50 μm is fixedly formed on each of the brazing surfaces of a light member made of Si, and then these both members contain Si: 0.1 to 14% by weight.
A method for manufacturing a composite brazing member, which comprises performing vacuum brazing using a brazing material made of an Al alloy.