JPS61229485A - Method and device for diffusion joining of metallic material - Google Patents

Abstract

PURPOSE:To remove the oxide and gas on the interface, to destroy the microundulation on the surface and to shorten the joining time by giving a vibration on the joining interface prior to the joining at the joining temp. CONSTITUTION:The vibration by an exciter 1 is transmitted to a spacer 4 by an exciting rod 3 and further transmitted to the material 5 to be joined which is held by the spacer 4. This vibration vibrates on the joining face with the joining material 5 being held by the spacer 4 of the above of a load bearing base 7. The vibration acts at right angles on the joining face. A space is opened on the joining face so that no load is placed thereon in advance, a pressure rod 2 is descended on starting of the vibration and when the pressure is increased with the contact of the joining face to be pressurized, the vibration becomes overload and only the pressure remains with the actuation of a stopping circuit. It is held at the temp. lower than the melting point of the material to be joined by reducing the pressure slowly after holding the pressure for the prescribed time and by raising the heating temp. by a heater 8 simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to pressurization during bonding of metal materials, and particularly to a suitable diffusion bonding method and an apparatus for carrying out the method.

[Background of the invention]

Diffusion bonding involves heating the bonding material above its recrystallization temperature in a vacuum or an inert gas atmosphere, applying appropriate pressure, and bonding by atomic diffusion. Therefore, the method and timing of pressurization are important bonding factors.

The conventional pressurization method is the second one of Japanese Patent Publication No. 59-48713.
As shown in the figure, the bonding material is heated to a temperature below the melting point, and when that temperature is reached, a constant pressure of 1lL1~1
0 Yu/-2 for a constant heating time of 1 minute to 2 hours. The application force contributes to the contact between the joining surfaces, and it is stated that it is important to apply uniform pressure to the joining materials.

However, in this method, due to the static pressure, the micro protrusions on the joint surface yield and the contact surface increases compared to the finished state, but it is not perfect. Moreover, if the smoothness of the protrusion is poor, the pressing force must be increased. No consideration was given to the release of a small amount of gas from the vicinity of the surfaces to be joined during pressurization and the effect of pressurization on the removal of impurities from the surfaces to be joined due to this.

[Purpose of the invention]

The purpose of the present invention is to effectively release trace gases from the surfaces to be joined during the temperature rising process and remove accompanying impurities, which were not considered in conventional pressurization methods, and to eliminate pores and non-metallic surfaces from the surfaces to be joined. An object of the present invention is to provide a diffusion bonding method and an apparatus therefor that prevent defects caused by inclusions.

[Summary of the invention]

To summarize the present invention, the first aspect of the present invention relates to a method for diffusion bonding metal materials, and in the method for diffusion bonding a pair of metal material bonding materials, the materials to be bonded are heated to a predetermined temperature. step, a vibrating step of applying vibration to at least one of the bonding materials at a distance where the bonding surfaces do not contact each other during and/or after the heating, and a step of bringing the bonding surfaces into contact and applying pressure after the vibration. It is characterized by

A second invention of the present invention relates to an apparatus used in the above method, which apparatus includes a round heating equipment for heating the materials to be joined, and a device for applying a swelling force to the materials to be joined. It is characterized in that it includes a pressurizing equipment and a vibration equipment for applying vibration to at least one of the materials to be joined.

Metal materials, even those made through well-controlled manufacturing processes, contain several thousand ppm to several tens of ppm of gas as impurities. These gases are present in the material as pores or nonmetallic inclusions. Since the solubility of these gas components increases in high-temperature metals, they tend to collect in heated areas, and the gas concentration is high in the high-temperature areas of the bonding surfaces. Therefore, in the present invention, the joint surface is vibrated to deform and break the microscopic undulating surface, and at the same time, the gas in at least that portion is released from the material. At the same time, it is possible to mechanically remove oxides at the bonding interface caused by gas released during the temperature rising process. Also,
As the undulations on the material surface are destroyed by vibration, a new surface of the material appears and metal diffusion during bonding is facilitated, resulting in a highly reliable bonded surface.

The frequency given during bonding is 50 Hss - S D KH
You can select up to z. At frequencies below 50 Hg, oxides at the bonding interface cannot be removed.

Further, if the temperature exceeds 30 K) IZ, it is difficult to obtain the vibration necessary to remove the oxide, and as a result, the oxide cannot be removed.

Note that when the frequency is low, the amplitude is increased to remove oxides by the action of contact at the bonding interface.

Furthermore, when the frequency is high, the amplitude may be reduced, and the oxide will be peeled off by the energy of the movement. These amplitudes vary depending on the frequency applied, but are between 5 μm and 2 o o p
It is effective to select within the range of m.

If the joint surface is rough or the material is relatively hard, select the low frequency-high amplitude condition, and if the surface is fine or the material is hard, select the high frequency-low amplitude condition. The vibration time can be any time if the bonding interface does not contact, but it should be at least 3
The time is preferably at least 1 minute, and once the bonding interface comes into contact, a short time of several seconds is sufficient.

In addition, the bonding of the present invention may be performed by the conventional method of diffusion bonding.

First, an intermediate material that promotes bonding can be provided between the joining surfaces, and there is no need for an intermediate material. The intermediate material may be an alloy containing 31-day-1 grade, and the material to be joined may also be a metal or alloy with a low melting point.

Further, the bonding may be performed in a vacuum.

Furthermore, in the heating step, without melting the bonding material of the joint part, if an intermediate metal is present, heating to a high temperature in a temperature range in which the intermediate metal does not melt, followed by vibration and pressure, Bonding may be performed by performing post-heat treatment.

Alternatively, the temperature in the heating step may be set to the bonding temperature, and the bonding may be completed by applying vibration and pressure.

On the other hand, in the device as well, the joint portion may be a vacuum chamber, or a spacer may be used, as usual. In other words, it corresponds to a vibration equipment added to a normal diffusion bonding apparatus.

[Examples of the Invention] Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited thereto.

Note that FIG. 1 is a schematic cross-sectional view of an example of the device of the present invention,
FIG. 2 is a graph showing the relationship between time (horizontal axis), temperature, excitation and pressure (vertical axis) in one example of the method of the present invention.

Embodiment 1 Hereinafter, one embodiment of the present invention will be described using the configuration diagram of a diffusion bonding apparatus shown in FIG. Reference numeral 1 is a vibration excitation device, which is configured with a pressure rod 2, and the vibration rod 3 generates vibrations, and the vibration rod 4
is transmitted to the spacer. Further, this vibration is transmitted to the welded material 5 held at 4. This vibration vibrates at the joint surface of the load holder 7 with the joining material 5 held by the spacer 4. 6 is a vacuum chamber, which has a structure to cool the radiant heat from the heater 8. The material to be joined in 5 is a pair of SUE
14 material was machined to ensure accurate parallelism of the plate thickness, and the joint surfaces were finished to a roughness of 10 to 6 μm.

After that, about 1 layer of Ni-0r material containing some boron was applied to that surface.
Aiming for a thickness of 5 pm, the vapor was deposited only on the upper side of the materials to be joined, that is, on the joining surface of the material transmitted by the vibrating rod 3. As can be seen from FIG. 1, the vibration acts perpendicularly to the joint surface. FIG. 2 is a graph showing the relative relationship between temperature, vibration, and pressure during bonding as described above. The vacuum furnace was maintained at 10-5 Torr.

The joining temperature is lower than the melting point of the materials to be joined.1070
℃, the temperature rises to a in Figure 2, but the frequency of vibration applied to the bonding material at time a' before this bonding temperature is 1d 20 K
The amplitude is 20 μm at Hz.

Leave a space in advance so that no load is applied to the joint surfaces, and when the vibration starts, the pressure rod is lowered and the pressure is applied. When the joint surfaces contact and the pressure increases, the vibration goes over the rod. The stop circuit is activated, and the pressure (12 Yu/■1) only. This vibration was continued for over 3 minutes until substantial contact was made. A short period of 10 to 15 seconds may be sufficient after substantial contact has occurred.

After applying pressure, if this pressure is removed and vibration is applied again, vibration may occur depending on the degree of bonding, but in that case, apply a slightly higher pressure than the previous time. The pressure holding time is 5
After that, the pressure was gradually lowered and at the same time the heating temperature was raised and held at 1100° C., which is a temperature lower than the melting point of the materials to be joined, for 10 minutes.

As a result of microscopic observation of the cross-section of the joint thus joined, it was found that the structure of the joint was fine and no cavity defects were observed.

Example 2 Next, BUB 304 and a zirconium alloy were also tested. In this case, the vapor deposition of the intermediate metal was omitted and the same conditions as above were used. As a result, there were no defects on the bonded surfaces and a perfect bonded state was observed.

[Effects of the Invention] According to the present invention, since vibration is applied to the bonding interface before bonding at the bonding temperature, oxides and gases at the interface can be removed, and furthermore, microscopic undulations on the surface are destroyed and new metal is formed. Since a plane is formed, the bonding time can be significantly shortened. In addition, since the oxides at the interface are removed, the joint surface is clean and a joint with excellent strength and metallurgy can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of one example of the diffusion bonding apparatus of the present invention, and FIG. 2 is a graph showing the relative relationship between temperature and excitation and pressing force in one example of the method of the present invention. 1: Vibration device, 2: Pressure rod, 3: Vibration rod, 4 Ni spacer, 5: Material to be joined, 6: Vacuum chamber, 7: Load holder,
8: Heater

Claims (1)

[Claims] 1. In a method of diffusion bonding a pair of metal material bonding materials, the step of heating the materials to be bonded to a predetermined temperature, and the step of bonding at a distance where the bonding surfaces do not come into contact with each other during and/or after the heating. A method for diffusion bonding metal materials, the method comprising the following steps: a vibrating step of applying vibration to at least one of the materials, and a step of bringing bonding surfaces into contact and applying pressure after the vibration. 2. The method for diffusion bonding metal materials according to claim 1, wherein following the step of applying pressure, diffusion bonding is performed by heating to a temperature higher than the predetermined temperature. 3. The method for diffusion bonding metal materials according to claim 1, wherein the predetermined temperature is a bonding temperature, and the bonding is completed in the step of applying the pressure. 4. In an apparatus for diffusion bonding a pair of metal material joining materials, heating equipment for heating the materials to be joined, pressurizing equipment for applying pressure to the materials to be joined, and vibration on at least one of the materials to be joined. 1. A diffusion bonding apparatus for metal materials, characterized in that it includes vibration equipment for imparting vibration.