JPH0575507B2 - - 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, as reflectors for carbon dioxide gas, for example, mirrors made of pure Cu with a mirror finish, and mirrors made of pure Cu with an Au plating on the mirror surface have been known. There is. However, with these pure Cu reflectors,
As the laser irradiation time increases, metal and non-metal vapor generated from the processed material adheres to the surface, which not only reduces its reflectance, but also causes the surface to absorb the laser energy, melt, and reflect. Accidents such as damaging mirrors have occurred. In order to prevent such accidents, it is necessary to regularly remove deposits from the surface, but since the pure Cu and Au plating that makes up the reflector is very soft, when wiping it off, it is necessary to remove the deposits from the surface. The surface is easily damaged, resulting in loss of reflective properties. For this reason, in recent years, hard pure copper has been used as a material for carbon dioxide laser reflectors, replacing pure Cu.
The use of Mo is becoming established. This purity
Mo reflecting mirrors, especially single crystal ones and polycrystal ones with fine grains, are easy to polish to provide a surface with uniform reflectance, and also have excellent performance with less adhesion of evaporated matter. It is something that demonstrates the. [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 need for lighter weight devices. Accordingly, there is a strong desire to reduce the weight of reflective mirrors made of pure Mo or pure W, which have a high specific gravity (heavy). [Means for Solving the Problems] Therefore, from the above-mentioned viewpoint, the present inventors have developed a material made of pure Mo that constitutes the reflecting mirror of the carbon dioxide laser, the inner wall material of the vacuum furnace, and the like. As a result of focusing on various parts made of heavy Mo alloy, pure W, or W alloy, and conducting research to reduce their weight, we found that pure Mo, Mo alloy,
A part of a heavy member made of either pure W or W alloy is replaced with lightweight (low specific gravity) pure W.
If it is made of lightweight material such as Ti or Ti alloy, the weight will be reduced accordingly, but for example, the specific gravity of pure Mo and pure W is 10.2 g/cm ³ and 19.3 g/cm ³ , while pure Ti The specific gravity of is 4.5 g/ ^cm3 , and the coefficient of thermal expansion of pure Mo and pure W is 5.1×10 ^-6 /℃ and 4.5×10 ^-6 /℃, while that of pure Ti is 8.9× 10 ^-6 /℃, these heavy materials and lightweight materials have different characteristics in various respects, and it is difficult to braze these two materials with high joint strength. However, it was impossible to reduce the weight of these parts by forming a Cu layer with an average thickness of 0.01 to 50 μm on each of the brazed surfaces of these two parts using the ion plating method. When vacuum brazing is performed using an Al alloy brazing filler metal containing 0.5 to 14% by weight, these two components will be firmly joined, resulting in a composite brazed component that is brazed with high joint strength. I have gained knowledge that this will happen. This invention was made based on the above knowledge, and it is based on pure Mo, Mo alloy, pure W, and W.
An average layer thickness of 0.01 to 50 μm is applied by ion plating to the brazing surface of a heavy component made of any of the alloys and the brazing surface of a light component made of pure Ti or a Ti alloy. of
The Cu layer is fixedly formed, and then these two members are bonded together.
This method is characterized by a method of manufacturing a composite brazing member in which vacuum brazing is performed using an Al alloy brazing filler metal containing 0.5 to 14% by weight of Si. In the method of this invention, the average layer thickness of the Cu layer is limited to 0.01 to 50 μm because if the average layer thickness is less than 0.01 μm, the wettability with the brazing material will be insufficient and the desired strong bonding strength will not be achieved. On the other hand, if the average layer thickness exceeds 50 μm, internal strain will remain during the formation of the Cu layer, which will not only cause peeling of the Cu layer during brazing, but also cause the solder to deteriorate. This is based on the fact that the Cu concentration in the material becomes high, especially near the brazing surface of the component, and as a result, the strength of the brazing material decreases. Also, regarding the Si content of the filler metal,
If the content is less than 0.5% by weight, the formation of a silicide layer on the brazed joint surface will be insufficient, making it impossible to ensure sufficient joint strength, while if the content exceeds 14% by weight If the brazed joint surface becomes brittle and thermal distortion occurs in the composite brazed component, peeling will easily occur at the joint, so the content should be set at 0.5 to 14% by weight. Established.
Furthermore, on the surfaces of both of the above-mentioned components, especially the light components, there is an oxide film that reduces the wettability of the brazing filler metal, but according to the ion plating method, this oxide film is removed while forming a Cu layer. This makes it possible to significantly improve the wettability of the brazing material, so forming a Cu layer using the ion plating method is essential, and it is especially necessary when brazing involves face-to-face bonding. It increases sex. [Example] Next, the method of the present invention will be specifically explained with reference to Examples. As heavy members, various members having the composition shown in Table 1 and having dimensions of diameter: 100 mm x thickness: 2 mm were prepared, and as light members, the compositions also shown in Table 1 were prepared. Prepare various parts with dimensions of 100 mm in diameter x 18 mm in thickness, then use an ion plating device on one side of these parts to be brazed.
After ion cleaning under normal conditions, a Cu layer of the average layer thickness also shown in Table 1 is fixedly formed, followed by a solder with a thickness of 0.3 mm having the composition also shown in Table 1. The materials are sandwiched between the brazed surfaces of both components, with the heavy component facing down, and a 20 kg weight is placed on top of this, under normal conditions, that is, a pressure of 1 x 10 ^-4 torr. Methods 1 to 4 of the present invention and comparative methods 1 to 4 were carried out by performing vacuum brazing under conditions of holding the temperature at 620° C. for 15 minutes in a vacuum. In addition, Comparative Methods 1 to 4 are based on any of the conditions (first

〔Effect of the invention〕

From the results shown in Table 1, it can be seen that in the composite brazed parts manufactured by methods 1 to 4 of the present invention, pure Mo, Mo alloy, pure W, which were conventionally considered to be extremely difficult to join by brazing, It is clear that the heavy member made of any of these alloys and the light member made of pure Ti or Ti alloy are brazed with strong joint strength. On the other hand, as seen in Comparative Methods 1 to 4, if any of the conditions falls outside the scope of the present invention, brazing with strong bonding strength will not be achieved. As mentioned above, according to the method of this invention, pure
A heavy member made of Mo, Mo alloy, pure W, or W alloy, and pure Ti or Ti
Since it is possible to braze a light member made of an alloy with a strong joint strength, it is possible to replace a part of the heavy member with the light member, making it possible to create a composite brazed member that is lighter in weight. In addition to being easy to manufacture, the lightweight member has high strength and excellent cooling effect.
For example, when used in the manufacture of reflectors for carbon dioxide lasers or inner wall materials for vacuum furnaces, the resulting composite brazing is combined with the excellent durability of the components against thermal cycles. This brings about industrially useful effects such as superior performance over a long period of time.

Claims (1)

[Claims] 1. A brazing surface of a heavy member made of pure Mo, a Mo alloy, pure W, or a W alloy, and a brazing surface of a light member made of pure Ti or a Ti alloy. A Cu layer with an average layer thickness of 0.01 to 50 μm is fixedly formed on each of the mounting surfaces by ion plating method, and then both these members are coated with Si: 0.5 to 14% by weight.
1. A method for producing a composite brazed member, which comprises performing vacuum brazing using a brazing filler metal made of an Al alloy containing