JPS6228091A - Joining method for ceramics - Google Patents

Abstract

PURPOSE:To join ceramics and another metal by interposing an aluminum alloy contg. <(0.2-6.8%) silicon to the surface to be joined of the ceramics and heating the same. CONSTITUTION:Aluminum alloy foil 2' contg. <(0.2-6.8%) silicon is interposed to the surface to be joined of the ceramic part 1 consisting of silicon nitride, etc. and the ceramic part and the metal 5 to be joined are heated under the pressure to diffusively join the boundary part between the part 1 and the aluminum foil 2'. The joining is executed under the conditions of 520-590 deg.C joining temp., >=30min holding time and 0.1kg/mm<2> pressurizing force. The ceramics is thus used only for the part where service conditions are severe with high temp., corrosion, wear, etc. and the metal is used for the rest, by which the higher performance and higher reliability are obtd.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for joining ceramics.

[Prior art] For example, as corrosion-resistant and wear-resistant machine elements for rollers, valves, and bearings for industrial machinery, materials with better heat resistance, corrosion resistance, wear resistance, high-temperature strength, lightness, dimensional stability, etc. than metals are used. If ceramics that are superior in this point can be used, functionality or performance can be greatly improved.

Ceramics in particular are rich in resources and are worthy of attention from the viewpoint of raw material resources. Therefore, in order to use ceramics as the various mechanical parts mentioned above, a technique for joining ceramics and metals is required.

Conventional methods for joining ceramics and metals include adhesive methods, mechanical methods, and chemical methods. Among these, the adhesive method is a method for joining ceramic parts and metal parts using an organic adhesive such as a thermosetting resin or a metal adhesive such as cement. Mechanical methods include methods such as shrink fitting. Chemical methods include the Mo-Mn method.

In this method, the ceramic surface is metallized by heating MO-Mn mixed powder in wet hydrogen to high tHIU (approximately 1100° C.), and then brazing with metal.

[Problems to be Solved by the Invention] However, when ceramics and metals are bonded using these bonding methods, when used at high temperatures, the adhesive may lose adhesive strength or the bond may peel off due to a difference in thermal expansion coefficient. There was an easy problem. Furthermore, in the Mo-Mn method, the bonding pretreatment is extremely time-consuming and the range of its application is also limited.

The present invention has been made to eliminate the drawbacks of these joining methods.

[Means for Solving the Problems] The method for joining ceramics of the present invention comprises:
An aluminum alloy containing less than 0.2 to 6.8 (W/W) silicon is interposed at the boundary with the substance to be bonded to the ceramic and heated.

[Function] Therefore, ceramics and aluminum alloys containing less than 0.2 to 6.8% silicon, other metals, or ceramics can be joined.

[Example] A bonding method called diffusion bonding is generally known, and the present inventors focused on this diffusion bonding method and conducted various experiments and studies on bonding ceramics and metals. As a result, compared to ceramics, silicon is 0.2 to 6.8 (
It has been found that aluminum alloys containing less than W/W)% can be diffusion bonded.

Here, as the ceramic, silicon nitride (Si 3
N4), silicon carbide (SiC), zirconia (Zr
02), alumina (A/zo3), etc., and those containing a sintering accelerator, a solid solution forming agent, a reinforcing agent, etc. can also be used if necessary.

Figure 1 shows ceramic part 1 and silicon 0.2 to 6.8
%, and (b) shows the state before bonding, and (b) shows the bonded state. This bonding is performed by heating under pressure, and the boundary portion of the aluminum alloy component 2 in contact with the ceramic component 1 is diffusion bonded (joint portion 3), thereby integrating the two.

Various experimental results for this joining method are shown in FIGS. 2 to 4. Note that silicon nitride (Si3N4) is used as the ceramic component 1.

Figure 2 shows a pressure of 0.1 kgf/mm2 and a holding time of 30
Figure 3 shows the relationship between shear strength and bonding temperature in an Ar atmosphere.
Of/mm', shows the relationship between shear strength and holding time in an Ar atmosphere, and Figure 4 also shows the relationship between the welding temperature of 580°C and the holding time.
It shows the relationship between shear strength and pressing force at a holding time of 60 minutes.

Therefore, from these experimental results, the junction temperature should be set at 520~5
90°C (temperature slightly lower than the melting point of aluminum alloy containing less than 0.2 to 6.8% silicon), holding time for 30 minutes or more,
It was found that bonding could be achieved by setting the pressing force to 0.1 kgf/mm' or more.

In addition, aluminum alloy with 3i less than 0.2%, for example, 0.1
When a bonding experiment was conducted under the same conditions as above using an aluminum alloy containing 6% 3i, bonding was almost impossible. In addition, among the aluminum alloy solders specified by JIS etc., for example, B A containing 6.8 to 8.2% Si.
4343 wax is 571℃, and S t wo 11.0
BA4 N containing ~13.0%.

4, the wax begins to melt at 559°C, making in-phase bonding difficult.

The present invention is characterized in that diffusion bonding or brazing can be performed without using an A1 solder specified by JIS, that is, a solder having a silicon content of 6.8% or more.

FIG. 5 shows another embodiment of the present invention, in which ceramic parts 1 and 1 are interposed between them an aluminum alloy foil 2' containing 0.2 to 6.8% silicon, similar to the above. It is to be joined by a suitable method.

That is, in this case, a joint portion 3.3 is formed at the interface between the ceramic parts 1 and 1 by means of the aluminum alloy foil 2', and the ceramic parts 1 and 1 are integrated.

FIG. 6 shows yet another embodiment of the present invention, in which a ceramic component 1 and a metal component 4 other than aluminum alloy (Ti, 5083, etc.) containing 0.2 to less than 6.8% silicon are combined. The above-mentioned aluminum alloy foil 2' is interposed between them, and they are joined in the same manner as described above. That is, also in this case,
A joint 3, 3 is formed at the interface between the aluminum alloy foil 2' and the aluminum alloy foil 2'.
are formed and integrated.

FIG. 7 shows an application example of the present invention, in which a ceramic component 1 and a metal other than the above-mentioned aluminum alloy (SUS, SNCM, etc.)
The aluminum alloy foil 2' containing 0.2 to less than 6.8% silicon is interposed between the parts 5 and 5. However, in this case, the two are simply brought into contact and heated to 590° C. or higher under vacuum and inert conditions. Since this method is a brazing method, the aluminum alloy foil 2' forms a welded portion 3' at the interface between the ceramic component 1 and the metal component 5, and the two are integrated.

Note that the present invention is based on an aluminum alloy containing 0.2 to less than 6.8% silicon, and the effect is almost the same even if it contains one or more other elements besides silicon at the same time. Further, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various changes can be made without departing from the gist of the present invention.

[Effects of the Invention] As explained above, according to the present invention, since the aluminum alloy containing 0.2% to less than 6.8% silicon is interposed on the surface of the ceramics to be joined and heated, the ceramics and the metal or It is possible to manufacture parts that are bonded with ceramics, and by using ceramics only in parts that are subject to severe usage conditions such as high temperatures, corrosion, and wear, and using metals in other parts, it is possible to improve the performance, reliability, and longevity of machines. It is possible to extend the service life.

[Brief explanation of drawings]

Figure 1 shows the joining method of the present invention, (a) shows the state before joining, (b) shows the joined state, and Figures 2 to 4 show the shear strength of the joined products, respectively. FIGS. 5 and 6 are diagrams showing the relationship between bonding temperature, holding time, and pressurizing force. FIGS. 5 and 6 also show other embodiments of the present invention, and (A) also shows the state before bonding. (0) is a diagram showing a bonded state, FIG. 7 is an application example of the present invention, and (A) is a diagram showing a state before bonding.
]) is a diagram showing a bonded state. 1 is ceramic parts, 2 is silicon 0.2-6.8%
Aluminum alloy parts containing less than 2' is silicon 0.2~6
．． Aluminum alloy foil containing less than 8%, 3 indicates joint, 4 indicates metal. Patent application Hitoshi Kawajima Harima Heavy Industries Co., Ltd. Figure 5 (a) (b) Figure 6 (a) (b) Figure 7 (a) (b) Figure 1 (a) (b) Figure 3 retained Time 1hl Figure 2 Bonding temperature (°C) Figure 4 Pressure force (Kgf/mm21

Claims (1)

[Claims] 1) Ceramic bonding characterized by heating an aluminum alloy containing 0.2 to 6.8 (W/W)% silicon at the interface between the ceramic and the substance to be bonded to the ceramic. Method.