JPH0378181B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a carbon dioxide laser reflecting mirror material that is lightweight and has a high cooling effect.

[Conventional technology]

In general, as reflecting mirrors for carbon dioxide lasers, for example, mirror-finished pure copper surfaces or gold-plated surfaces are used.

However, with these copper 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 become exposed to the laser. Accidents have occurred in which the metal absorbs energy and melts, damaging the reflector.

To prevent such accidents, it is necessary to regularly remove deposits from the mirror surface, but the pure copper and gold plating that make up the reflective mirror are very soft, so the mirror surface is easily damaged when wiped off. Reflection properties were frequently impaired.

For these reasons, in recent years, the use of hard Mo instead of pure copper has become popular as a reflective mirror material for carbon dioxide lasers. Further, as these metal reflecting mirror materials, single crystal ones and polycrystal ones with fine crystal grains are particularly excellent because they have less adhesion of evaporated substances.

[Problem that the invention seeks to solve]

On the other hand, since carbon dioxide gas laser equipment is installed not only on ground equipment but also on space stations, there is a demand for the equipment itself to be lighter, and as a result, the relative weight ( It is strongly desired to reduce the weight of the heavy Mo reflector.

[Means for solving problems]

Therefore, from the above-mentioned viewpoint, the present inventors focused on a carbon dioxide laser reflector made of Mo, and constructed a part of the Mo that constitutes it from lightweight (low specific gravity) Al or Al alloy. As a result of conducting research to reduce ^weight by 10 ^-6 /
°C), and thermal conductivity (Mo: 0.35cal/cm・sec・
It was recognized that it would be extremely difficult to braze these with high bonding strength because their properties differ significantly in various respects such as ℃, Al: 0.53 cal/cm・sec・℃). They found that if an Al alloy containing 8 to 14% Si by weight is used as the material and brazed in a vacuum, it is possible to braze Mo and Al or Al alloy with high bonding strength. .

This invention was made based on the above knowledge, and consists of a surface member made of a Mo plate, a base material made of an Al or Al alloy plate, and an Al alloy brazing filler metal containing 8 to 14% by weight of Si. The carbon dioxide laser reflecting mirror material is made of a composite brazed member that is brazed using carbon dioxide.

In addition, in the reflective mirror material of this invention, the Si content of the Al alloy brazing material is set to 8 to 14% by weight because:
If the content is less than 8% by weight, the melting point of the filler metal will decrease.
If the temperature exceeds 600℃, it may have a melting point higher than that of the base material, making brazing impossible. On the other hand, even if its content exceeds 14% by weight, This is because not only does the temperature exceed 600°C in some cases, but also the reaction with the Mo plate becomes significant, causing erosion.

〔Example〕

Next, the reflective mirror material of the present invention will be specifically explained with reference to Examples.

Example 1 Average grain size of 10 μm and diameter: 200 mm×
Prepare a Mo plate material as a surface member with dimensions of 1.1 mm in thickness and a pure Al plate material (JIS 1100) as a base material with dimensions of diameter: 200 mm x thickness: 20 mm.
These two plates were stacked together with a 0.3 mm thick Al alloy brazing filler metal containing 8.1% by weight of Si and the remainder consisting of Al and unavoidable impurities.
In this state, in a vacuum of 10 ^-5 torr, temperature: 610℃
Reflective mirror material 1 of the present invention was manufactured by vacuum brazing under conditions of holding for 10 minutes to obtain a composite brazed member.

Example 2 A Mo plate material as a surface member made of single crystal Mo having dimensions of diameter: 100 mm x thickness: 1.1 mm, and an Al alloy plate material (JIS 3003) as a substrate having dimensions of diameter: 100 mm x thickness: 20 mm. ) and both of these plates contained 11.3% by weight of Si and the rest was Al.
Thickness: 0.3 with a composition consisting of and unavoidable impurities
This is achieved by stacking Al alloy brazing filler metal of 1.5 mm in size and vacuum brazing it in a vacuum of 10 ^-5 torr at a temperature of 595°C for 10 minutes to create a composite brazed member. Invention reflective mirror material 2 was manufactured.

Example 3 As a surface member, a Mo plate made of polycrystalline Mo having dimensions of diameter: 150 mm x thickness: 1.1 mm and with an average crystal grain size adjusted to 5 μm was used, and as a base material, a Mo plate material having dimensions of diameter: 150 mm x thickness: 1.1 mm was used as a base material. Al alloy plates having a thickness of 20 mm and containing 1% by weight of Si and the rest consisting of Al and unavoidable impurities were prepared. Al alloy brazing filler metal with a thickness of 0.3 mm and having a composition consisting of aluminum and unavoidable impurities are stacked together, and in this state, in a vacuum of 10 ^-5 torr at a temperature of 595°C for 10 minutes. The reflective mirror material of the present invention was manufactured by vacuum brazing under holding conditions to obtain a composite brazed member.

〔Effect of the invention〕

When the weights of the reflective mirror materials 1 to 3 of the present invention obtained as a result were measured, they were 2.1Kg and 0.5Kg.
Kg and 1.2Kg, both of which are approximately 1/3 of the weight of the case where the entire body was made of Mo, indicating a significant weight reduction.

In addition, regarding the reflective mirror materials 1 to 3 of the present invention, the surface of the Mo plate material is polished to a mirror surface by concave polishing,
On the other hand, a reflector for carbon dioxide laser is manufactured by providing eight radial cooling channels in most of the base material, and the former has a large diameter of 200 mm and has an output of 10 kW. ,time:
10 hours, or the latter two diameters: 100mm and
For the small size with 150mm output:
It was put into practical use under the conditions of 5kW and 20 hours.
Coupled with the fact that the base material was made of Al or Al alloy, which has a higher cooling effect than Mo, no deformation was observed in the reflector after use.

As mentioned above, the reflective mirror material of the present invention is lightweight.
Since it is made of Al or Al alloy plate base material and Mo plate material as the surface member brazed, it is not only lightweight, but also the Al and Al alloy plate material that makes up the base material has a high cooling effect, so carbon dioxide gas When used as a laser reflector, it exhibits outstanding performance over a long period of time.

Claims (1)

[Claims] 1. A composite brazed member formed by brazing a surface member made of a Mo plate material to a base material made of an Al or Al alloy plate material using an Al alloy brazing material containing 8 to 14% by weight of Si. Reflective mirror material for carbon dioxide lasers.