JPS604050A - High heat-resistant load member - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention is composed of a CLI-Mo alloy composite structure that has good thermal conductivity and is less prone to thermal stress, deformation, etc. under high heat flow rate loads. The present invention relates to a high heat load resistant member.

[Technical background of the invention and its problems]

In components that are subjected to high heat flux loads at high temperatures, such as impurity removal plates for plasma generators, from the viewpoint of heat resistance or spatter resistance, a Mo layer is used in the surface layer that is directly subjected to high heat flow velocity loads. On the other hand, in order to effectively cool and remove the heat under load, it is necessary to use Cu or a Cu alloy in the cooling part, and for this purpose high heat load resistant members made of a Cu-Mo composite structure are used. The use of was tried and failed. At this time, the Cu layer and the Mo layer can be joined by a mechanical joining method such as bolt tightening, or by silver soldering.

Metallurgical joining methods such as copper brazing are known.

However, the thermal expansion coefficient of Cu and MO is, for example, 14.7xlO in the temperature range of 20°C to 600°C.
.

Mo: 5.4 x 10' (unit deg-')
Because of this large difference, Cu-Mo bonded bodies had the disadvantage that large thermal stress was generated in the bonded area due to temperature changes. Also, due to this thermal stress, metallurgy, which is usually carried out at elevated temperatures, However, in mechanical bonding methods, it is difficult to form a bond itself, and the shape of the bond.

Although it is possible to release the difference in thermal expansion and avoid the generation of thermal stress by considering the spacing, etc., the efficiency of heat transfer at the joint is poor, making it difficult to effectively remove the heat load. In a plasma generating device, when a large heat input such as plasma disruption occurs, the surface temperature increases, and there is a possibility that damage such as surface melting may occur. on the other hand,
If a metallurgical bonding method is used, heat is initially removed effectively, but thermal stress is generated on the bonding surface due to the difference in thermal expansion.
Particularly in tokamak-type plasma generators that operate in an intermittent operation mode, fluctuations in thermal stress and electromagnetic force from the plasma are also significant, leading to fatigue cracks, especially in weak joints.

Due to the occurrence of this crack, the efficiency of υ heat transfer deteriorates,
Similarly, there is a drawback that an increase in surface temperature ultimately causes damage such as surface melting.[Object of the Invention] The present invention aims to improve the above-mentioned drawbacks and to provide a heat conductive material with good heat conductivity. It is an object of the present invention to provide a high heat load resistant member made of a Cu-Mo alloy composite structure that generates less stress.

[Summary of the Invention] The high heat load resistant member of the present invention has a Mo layer (1) on the surface layer and a Cu layer (4) on the other end as shown in the cross-sectional view of the composite structure in FIG.
), and the intermediate layer between them is a Mo layer (1).
The Mo content on the side (2) near the Cu layer (4) is higher than the Mo content on the side (3) near the end of the Cu layer (4), in other words, from the side (2) near the surface layer made of Mo, Mo content ratio up to the side (3) near the end is 100~Ow
It is composed of a Cu-Mo alloy layer with a content of up to t%.

Cu-M constituting the high heat load resistant member according to the present invention.

For alloy composite structures, the middle part of the composite structure is M.

and Cu-M, which has a coefficient of thermal expansion intermediate to that of Cu.

This was achieved after discovering that the alloy layer can reduce the generation of thermal stress due to the difference in thermal expansion coefficients during high heat loads, and that it can prevent the deterioration of heat transfer efficiency at the bonding surface between Cu and Mo, which is caused by conventional methods.

[Embodiments of the invention]

Example 1 Mo powder having an average particle size of 5 μm is put into the lower surface of a mold to a predetermined thickness tl.

Next, Mo powder with an average particle size of 25 μm is coated on this top surface to a thickness of 1 t! Put it in. Furthermore, on the upper surface of this t2, an average grain size of 5
Add 0 μm Mo powder to a thickness of t, 1 ton/cJ
A plate-shaped green compact with a thickness of 20 s+a was formed at a pressure of .

Next, the Mo powder side of the plate-shaped powder compact with an average diameter of 5 μm was
Keep the other end at 50℃ and 1300℃ for 5 hours in a hydrogen stream.
sintering of r. After the sintered body is placed, the carbon melt is sintered at high temperature to increase the density (average grain size 5 μm).
(Mo powder side) facing downward, and 11
After raising the temperature to 50° C., Cu was charged into the upper part of the carbon crucible and melted to impregnate it into the Mo sintered body. A large amount of Cu was added to form an additional 25 cm Cu layer on the top of the compacted sintered body, which was then cooled and solidified.

As shown in Fig. 2, the resulting composite structure of Cu-Mo alloy impregnated with CU is prepared by making holes (5) for water cooling in the Cu layer (4). A high heat load resistant member (6) was formed from a composite structure of.

In addition, in the MO sintered body part of the Cu-Mo alloy composite structure, the Mo content on the surface layer side (2) of the Mo powder sintered body with an average grain size of 5 μm, that is, on the high temperature sintered side, is about % by weight. 95%, Mo content ratio on low temperature sintering side (3) is wt%
It was about 60%.

(Comparative Example 1) One side of a Mo layer (1') manufactured by powder metallurgy with a thickness of 110 m+ was plated with Cu (8) to a thickness of 10 μm, and then a circular hole for cooling water was provided. 30s
A silver soldering foil (9) with a thickness of 25 μm is placed between the Cu layer (41) of am and the Cu layer (41) is stacked, heated to 850°C in H1 air flow under a load of 2#/-, and slowly cooled to form a Cu layer. A high heat load resistant member (1CJ) shown in FIG. 3 was formed of a -Mo composite.

A heating cycle trial run in which a heat flux of psooW/d was applied to the MO surface of the MO surface by an electron beam for 60 seconds, and then paused for 30 seconds, while cooling water was passed through the high heat load resistant member produced by the manufacturing methods of Example 1 and Comparative Example 1. was performed 50 times.

Then, the MO surface temperature was measured at the end of 60 seconds of heating, and the occurrence of peeling, cracking, etc. at the joint after the heating cycle test was observed.

The results of these tests are shown in Table 1.

As shown in Table 1, the high heat-resistant load member of the present invention, which is made of a composite structure of Cu-Mo alloy according to the present invention, has good thermal conductivity and generates little thermal stress, so it has high heat resistance. It is fully suitable for use as a heat-resistant load member.

〔Effect of the invention〕

As explained above, a high heat load resistant member made of a composite structure of Cu-Mo alloy is made of Mo
Since there is a Cu-Mo alloy layer with a thermal expansion coefficient between the two and Cu, there is no joint, even under repeated high heat loads, so the joint does not peel off.
Has sufficient heat removal effect.

Furthermore, the high heat load resistant member according to the present invention includes Mo and Cu.
Due to the continuous change in the thermal expansion coefficient of the Cu-Mo alloy in the intermediate layer between MO and CuO,
It is also industrially useful because it is possible to suppress the occurrence of cracks on the surface of P and Mo, which have small thermal stress or thermal strain caused by the difference in thermal expansion coefficients.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a high heat load resistant member of the present invention, Fig. 2 is a sectional view of a high heat load resistant member of the present invention, and Fig. 3 is a sectional view of a conventional high heat load resistant member. One is Mo, (2
), (31 is a Cu-Mo alloy layer whose composition changes, (
41, (4') is cu, (6), Ql is a high heat load resistant member. Agent: Patent attorney Kensuke Chika (and 1 other person)

Claims (1)

[Claims] The Mo layer and the Cu layer are Mo layered from the Mo layer side to the Cu layer side.
Cu-M whose content ratio changed from 100 to 0% by weight
o A high heat-resistant load member comprising a composite structure laminated with an alloy layer interposed therebetween.