JPH0338946B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention relates to a method for manufacturing a composite brazed member that is lightweight, has a high cooling effect, and is suitable for use as, for example, a reflector for a carbon dioxide laser or an inner wall material for a vacuum furnace. It is. [Prior Art] Conventionally, for example, as a carbon dioxide gas reflecting mirror, a mirror-finished pure Cu surface or a mirror-finished surface, or a mirror plated with Au plating, etc., have been used. However, with these Cu reflectors, when the laser irradiation time becomes long, metal and non-metal vapors generated from the processed materials are deposited on the mirror surface, which not only reduces the reflectance, but also causes the mirror surface to be exposed to the laser. Accidents have occurred in which the mirror absorbs energy and melts, damaging the reflector. To prevent such accidents, it is necessary to regularly remove deposits from the mirror surface, but since the pure Cu and Au plating that makes up the reflective mirror is very soft, it is easy to damage the mirror surface when wiping it off. , the reflective properties were frequently impaired. For this reason, in recent years, hard Mo has been used as a material for carbon dioxide laser reflectors instead of pure Cu.
The use of . As for this Mo reflector, single-crystal ones and polycrystal ones with fine crystal grains exhibit excellent performance with less adhesion of evaporated matter. [Problems to be solved by the invention] On the other hand, since carbon dioxide laser devices are installed not only in ground equipment but also in space stations, there is a growing demand for the device itself to be lightweight. , Along with this, there is a strong desire to reduce the weight of Mo reflectors that have a high specific gravity (heavy). [Means for Solving the Problems] Therefore, from the above-mentioned viewpoint, the present inventors developed Mo members such as Mo reflectors, Mo alloy members, and similar heavy W members and W alloys. As a result of focusing on components and conducting research to reduce their weight, we found that some components made of pure Mo, Mo alloy, pure W, and W alloy were made lighter (lower specific gravity). Composed of pure Al or Al alloy, while
For example, the specific gravity of pure Mo and pure Al (pure Mo: 10.2, pure
Al: 2.7), thermal expansion coefficient (pure Mo: 5×10 ^-6 /℃, pure
Al: 23.3×10 ^-6 /℃), and thermal conductivity (pure Mo:
0.35cal/cm-s-℃, pure Al: 0.53cal/cm-s-
It is extremely difficult to braze these two parts with high bonding strength because their properties differ significantly in various respects such as
Si: 3 to 14% by weight is preliminarily applied to the brazing surface of a member made of pure W or W alloy by means such as welding a foil or melt plating.
If a brazing material layer of an Al alloy containing Al alloy is firmly formed, and in this state it is overlapped with the brazing surface of a pure Al or Al alloy member, and vacuum brazing is performed through the brazing material layer, high bonding strength can be achieved. They obtained the knowledge that it is possible to perform brazing. This invention was made based on the above knowledge, and the brazing surface of a member to be brazed made of pure Mo, Mo alloy, pure W, or W alloy contains 3 to 14% by weight of Si. A brazing material layer having an average layer thickness of 0.1 to 1 mm is fixedly formed, and the brazing member is then bonded to a substrate made of pure Al or an Al alloy through the brazing material layer. This method is characterized by a method of manufacturing a composite brazed member, which comprises vacuum brazing the parts. In the method of this invention, the Si content of the brazing filler metal is limited to 3 to 14% by weight because if the content is less than 3% by weight, the melting point of the brazing filler metal will exceed 660°C, which is too high. There are cases in which a brazing temperature higher than the melting point of the substrate is required; Even if the amount exceeds 14% by weight, the melting point of the filler metal
The content was set at 3 to 14% by weight because not only would the temperature exceed 660℃, but also the reaction with the parts to be brazed would become significant and cause erosion. be. Also, the average layer thickness of the filler metal layer was set to 0.1 to 1.
mm is used because if the average layer thickness is less than 0.1 mm,
Unable to secure the desired strong joint strength,
On the other hand, if the average layer thickness exceeds 1 mm, the brazing filler metal protrudes from the brazing surface, making post-treatment troublesome. [Example] Next, the method of the present invention will be explained with reference to an example. Each member to be brazed has the composition shown in Table 1, and diameter: 100 mm x thickness: 2 mm.
A member having the dimensions is prepared, and a brazing material layer having the composition and average layer thickness shown in Table 1 is preliminarily applied to one side of the member to be brazed using the known means shown in Table 1. In other words, welding is performed by placing the brazing material on one side of the component to be brazed and heating it to a temperature of 700°C in a vacuum of ¹ The member to be brazed is fixedly formed by immersion in the brazing material, and then the member to be brazed is placed on the upper surface of a base having the composition shown in Table 1 and having dimensions of diameter: 100 mm x thickness: 20 mm. were stacked on top of each other through the brazing material layer, and a 5 kg weight was placed on top of the brazing material layer, and the pressure was 1×.
At a temperature within the range of 600-630°C in a vacuum of 10 ^-5 torr
The method 1 of the present invention is carried out by performing vacuum brazing under the condition of holding for 15 minutes and manufacturing a composite brazed member.
- 8 were carried out, respectively. Next, a specimen was cut out from the composite brazed member obtained as a result, and the tensile strength of the joint surface was measured, and the results shown in Table 1 were obtained.

〔Effect of the invention〕

From the results shown in Table 1, in methods 1 to 8 of the present invention, pure Mo, Mo alloy, pure W, which were conventionally considered to be extremely difficult to join by brazing,
and W alloy, and pure
It is clear that a member made of Al or an Al alloy can be brazed with strong joint strength. As mentioned above, according to the method of this invention, pure
Part of a heavy member made of Mo, Mo alloy, pure W, or W alloy is replaced with light pure Al
Or it can be replaced with Al alloy, so
It is now possible to reduce the weight of various heavy components, making it even more pure.
Al or Al alloy has an excellent cooling effect, so
For example, when applied to the manufacture of reflectors for carbon dioxide lasers and inner wall materials for vacuum furnaces, these materials exhibit industrially useful effects such as superior performance over a long period of time.

Claims (1)

[Claims] 1. The brazing surface of a member to be brazed made of any one of pure Mo, Mo alloy, pure W, and W alloy is made of an Al alloy containing 3 to 14% by weight of Si. A brazing material layer having an average layer thickness of 0.1 to 1 mm is fixedly formed, and then the member to be brazed is vacuum brazed to a base made of pure Al or an Al alloy through the brazing material layer. A method for manufacturing composite brazed parts.