JPH0378191B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to an adhesive paste suitable for joining metals to metals, metals to ceramics, and ceramics to ceramics. (Prior Art) Various joining methods have been known for joining the same materials, such as metal to metal, ceramic to ceramic, or joining different materials, such as metal to ceramic. For example, methods for joining metals include fusion welding methods such as electric welding, gas welding, and friction welding, and methods that do not melt the base materials include brazing and bonding methods using organic adhesives. In addition, the bonding methods for ceramics and ceramics include the bonding method using organic adhesives and the heat-resistant metal method (Japanese Patent Application Laid-open No.
61-58870). In contrast to these bonding methods between the same materials, methods for bonding dissimilar materials such as metal and ceramic include adhesive methods using organic adhesives, active metal methods, shrink fitting methods, and solid phase reaction methods. There is a heat-resistant metal method in which the base material is metallized with Mo, W, etc., then nickel plated and soldered to the metal base material.
Recent technologies include bonding methods based on chemical reactions, such as the creation of hydrated compounds using oxide-based inorganic adhesives. (Problems to be Solved by the Invention) However, among the various joining methods mentioned above, all of them, except for fusion welding, which is a unique method for joining metals together, have the drawbacks of being weak against heat and lacking in adhesive strength. . On the other hand, a few bonding techniques using vapor deposition, sputtering, thermal spraying, etc., and bonding techniques using foil insert materials have been proposed, but they not only have the disadvantage of poor adhesive strength, but also have a limited range of use. Therefore, it is not practical and cannot be said to be an economically satisfactory joining method. The present invention eliminates the drawbacks of the above-mentioned prior art, has heat resistance, high adhesive strength, and has metal,
The purpose of the present invention is to provide a new adhesive that satisfies practicality and economical efficiency and can be easily used not only for bonding between the same ceramic material, but also for bonding different materials such as metal and ceramic. . (Means for Solving the Problems) In order to achieve the above object, the present inventors first used a metallic adhesive in order to ensure heat resistance, and in this metallic adhesive, the adhesive strength was particularly improved. As a result of intensive research on ways to improve heat resistance and adhesive strength, we found that simply adjusting the chemical composition of conventional metal solders (e.g., Japanese Patent Publication No. 61-10235) limits its use, and that it is difficult to improve heat resistance and adhesive strength. It became clear that there was a limit to the requirements, and as a result of repeated experimental research focusing not only on adjusting the chemical components, but also on the physical structure of the adhesive.
It has a specific composition containing Ag as an essential component, and has a composite powder structure in which each component is mixed and coexisting as an adhesive structure, and this composite powder is dispersed in an organic solvent to form a paste. It has been discovered that the above objective can be achieved by this method. Incidentally, the particle structure was compared between a case where a composite powder was made using a mechanical alloying method using 45% Ag powder, 45% Cu powder, and 10% Ti powder, and a case where a mixed powder was simply mixed. In the case of a composite powder, it has a composite structure in which Ag, Cu, and Ti are intertwined with each other in a layered manner, as shown in a to b of FIG. This means that Ag is mainly distributed in the center from c when the Ag component is filtered, and Ti is mainly distributed on the outer periphery from d.
It can be seen from e that Cu is distributed between Ag and Ti, and it was confirmed that each component was alloyed from the X-ray diffraction data of f. In other words, it has a composite structure in which one particle is alloyed. On the other hand, in the case of mixed powder, the component particles are simply mixed together as shown in a to b in Figure 4, and this can be seen from c to e when each component is filtered.
It was found that Ag, Cu, and Ti were present independently in their original form, and this was confirmed by the X-diffraction data of f. That is, the adhesive paste according to the present invention has Cu
and 10 to 60% of at least one of Ni (hereinafter referred to as component A), and 10 to 80% of at least one of Ti, Nb, and Zr (hereinafter referred to as component B).
5ppm of at least one rare earth element (hereinafter referred to as D component), including Y as necessary.
~3%, with the remainder being substantially Ag (hereinafter referred to as C component) 10 to 80%, and each component particle is mechanically intertwined in a layered manner by a mechanical alloying method to solidify. It is characterized in that a composite powder alloyed in a phase state is dispersed in an organic solvent to form a paste. The present invention will be explained in detail below based on examples. The adhesive of the present invention is made into a paste, and the metal powder used therein is based on silver wax, nickel wax, copper wax, etc., which are known as the main components of conventional metal solders. Cu−
Using a ternary system of Ti-Ag as the base composition, we conducted experimental research on its physical structure. First, we divided the metal powder into a simple mixed powder state in which the above three components were simply mixed together, and a composite powder state in which the three component fine powders were mechanically intertwined in layers and alloyed in a solid state, and the metal powder in each of these states was We made it into a paste, investigated the bonding temperature (usage temperature) and the possibility of changes in the physical structure, and considered the bonding effect. As a result, no particular improvement in the bonding effect was observed in the case of a simple powder mixture state, and there was no organic relationship with the bonding temperature, whereas in the case of a composite powder state, if the bonding temperature was appropriately selected, It was discovered that the joint strength was significantly improved. This is because, as shown in Figure 2, the fine powders of each component are mechanically intertwined in layers and alloyed in a solid state, so the closely adjacent fine powders of each component melt on the surface at the bonding temperature. It is thought that this strengthens the bonds between the particles, which acts as a type of glue and increases the bonding strength. Incidentally, such an appropriate junction temperature (Ag
- When used in a state where each component is alloyed at a high temperature exceeding 800 to 900°C (Cu type), a phenomenon was observed in which the effectiveness decreased. In addition, in a simple mixed state, each component is in a separated mixed state, so even if heated, the above effect could not be expected. Based on the above basic experiments, we conducted further experimental research on the composition range of the three-component system, the addition of other elements, etc., and determined the chemical components that can be used as an adhesive. That is, FIG. 1 is a diagram showing the component system and composition range (wt%) of the composite powder in the adhesive paste of the present invention, where the A component consists of at least one of Cu and Ni, and the B component consists of Ti, Ti, In a component system consisting of at least one of Nb and Zr, and the remainder being C component (i.e. Ag), the composition range is 10 to 60% of A component, 10 to 80% of B component, and 10 to 80% of C component. %, it can be used as an adhesive exhibiting desired performance. In addition, if the A component exceeds 60%, adhesive strength will not be obtained, and the B component will
If it exceeds 80%, the hardness of the bonding layer becomes high and it becomes vulnerable to heat shock, which is not preferable. Among the above composition ranges, the range with excellent heat resistance and adhesive strength is 20 to 50% of A component and 10% of B component.
60% or less, and the C component is in the range of 20 to 50%. Note that it is preferable to use sponge titanium powder or carbonyl nickel powder for Ti and Ni. Ni is effective when bonding stainless steel plates. Furthermore, at least one rare earth element (including Y) can be added to the above-mentioned component system as the D component, if necessary. The amount to add is
Mitsushi Metal may be used at 5ppm to 3wt%. By adding component D, the lower limit of the addition rate of component B can be lowered to 7%.
Adhesive strength can be obtained even if the addition rate of is made small, and the effect is particularly noticeable when joining ceramic base materials such as SiC and graphite. A composite powder having the above chemical components can be produced by a so-called mechanical alloy method,
By mixing and pulverizing the metal powder of each component using a stirrer such as a crusher, ball mill, or attritor at high speed and high energy for the required time, the particles of each component are opportunistically intertwined in layers. A so-called mechanical alloy composite powder alloyed in a solid state is obtained. The composite powder preferably has a particle size of 44 μm or less, preferably 50 wt% or more of particles with a particle size of 10 μm or less. Mechanical alloying method (mechanical alloying)
This is a method of mechanically alloying component powders (that is, in a non-molten state or solid state). Coarse component powders are pulverized using a stirrer that can provide high speed and high energy. It fragments due to the elongation (cold forging) action, and the relatively ductile component fragments fold up other component fragments and intertwine to form a cohesive layered structure, which is further subjected to the elongation action, and finally becomes visible under an optical microscope. Indistinguishably homogenized, ie alloyed, particles are obtained. These particles can be said to be alloy particles in a solid state using the cohesive action between fragment particles of each component, and it can be easily confirmed that they are alloyed by X-ray diffraction. This composite powder is dispersed in an organic solvent to form a paste. As an organic solvent, terpineol, butyl carbitol, texanol, butyl carbitol acetate, etc. can be used, and the amount of metal powder in the paste is 60~90wt.
% is appropriate. In addition to the organic solvent, a small amount of a surfactant (eg, rosin wax) may be added, or ethyl cellulose or the like may be added as a binder. A preferred method of using the above adhesive paste is to first apply the required amount of adhesive paste to the adhesive surface of one or both of the base materials, such as metal or ceramic, and after drying, bake it at 550 to 600°C in an inert atmosphere. The binder content is volatilized, and then the bonding is performed by heating at 600 to 900° C. for a required time under a load of 1 to 100 Kg/cm ² in a non-oxidizing atmosphere or under reduced pressure of 10 ^-3 Torr or less. The coating amount is preferably about 30 to 60 μm in film thickness after firing. If it is too thin, diffusion will be insufficient and adhesive strength will not increase. Furthermore, if the thickness is too large (500 μm or more) and it is used on a ceramic substrate, the effect of the difference in thermal expansion will become large, causing cracks to occur in the ceramic plate. Regarding the heating temperature, when bonding ferrite, adhesive strength is exhibited even at a relatively low temperature of about 600°C. This is because the ferrite surface is Ti,
This is thought to be because it is reduced by Zr, Nb, etc. and produces an Fe phase. Generally, 830 to 900°C is preferred. 800
Below 950°C, the bonding strength is low; above 950°C, the bonding material will warp; heat treatment above 900°C will turn the adhesive into a molten alloy, reducing the bonding effect, so keep this in mind when bonding. It is necessary to determine the temperature. Since the adhesive is in the form of a paste, large quantities can be processed by printing it on the adhesive surface using a printing process and bonding the base materials. (Example) Next, an example of the present invention will be shown. Example 1 Sponge titanium powder, silver powder, copper powder, and mesh metal powder, all of which are powders of 326 mesh (44 μm) or less, were blended in the proportions (wt%) shown in Table 1, and ball milled so that the powder was 10 μm or less. It was mixed and ground using. Next, this composite powder was kneaded in a three-roll mill to form a paste having the blending ratio shown below. Composite powder 24 parts by weight Ethyl cellulose 4.4 Texanol 5 Surfactant 0.54 Next, as one of the substrates to be bonded, use a screen printing machine to print the above paste onto a 50 mm x 50 mm substrate using various materials shown in the same table. 30μm, area
Printed on 49mm opening. The screen used was made of 200 mesh stainless steel, bias tensioned, with an emulsion thickness of 45 μm and a patterned opening of 49 mm. After printing, after leveling at room temperature for 10 minutes.
It was dried at 105°C for 30 minutes. The dried product was further fired in a nitrogen atmosphere using a thick film firing furnace.
If fired at a high temperature of 700°C or higher, the bond will eventually fail, so in this example, the peak temperature was 600°C.
x 8 minutes for a 60 minute profile. The purpose of this firing is to volatilize the binder component in the paste. In the comparative example in Table 1
This is an example in which no bonding force was generated because the materials were fired at high temperatures of 800°C and 900°C. After firing, various materials were layered on the above substrate in the combinations shown in the table and heated under a vacuum of 10 ^-4 Torr.
A load of 10 kg/cm ² was applied and heat treatment was performed at a predetermined temperature of 900° C. for 1 hour to bond them. Ten bonded specimens prepared in this manner were each prepared and dropped onto the steel plate three times from a height of 50 cm, and the bonded state was visually observed. The results are also listed in the same table. The criteria for determining the bonding state in the same table are as follows. ○ mark: All 10 sheets did not peel at all △ mark: 1 to 2 sheets out of 10 sheets peeled on the adhesive surface × mark: 3 or more out of 10 sheets peeled off on the adhesive surface In this test, all 10 sheets It is most preferable to obtain a bonded state with no peeling at all, but even if only one sheet out of 10 peels off, it can be said to be of sufficient use.

【table】

[Table] As is clear from Table 1, the adhesive paste made only of Ti powder (No. 1) does not bond the base materials, whereas the adhesive paste with chemical components within the scope of the present invention and in powder form is suitable. Depending on the usage mode, a good bonding state can be obtained even with one-sided application. It was also confirmed that when both sides of the base material were printed in the same manner and bonded together, the adhesive strength was further increased. Example 2 A composite powder consisting of each component shown in Table 2 was produced in the same manner as in Example 1, and a paste having the blending ratio shown below was obtained. Composite powder 24 parts by weight Acrylic resin 4.4 Terpineol 5 Surfactant 0.54 Next, substrates to be bonded having various materials and dimensions shown in Table 2 were first degreased at 400°C in a N ₂ stream, and then The paste was printed on one substrate in the same manner as in Example 1 (however, the thickness was varied), and after drying and baking, various materials were stacked and bonded in the combinations shown in Table 2, and each bond was The bonding condition of each specimen was examined. In this case, if the thickness of the adhesive after firing was to be 15 μm or less, the paste was diluted with terpineol. In addition, when the thickness was 30μ or more, after printing, drying, and repeating the printing again, the desired thickness was achieved. The time required for bonding is 30 minutes unless otherwise specified. The results are also listed in Table 2.

【table】

[Table] (Note) ** Reference examples In Table 2, in particular, Nos. 14 and 15 are examples where the adhesive strength did not increase due to insufficient paste film thickness, and Nos. 20 and 21 are Ni-Ag based SUS Examples of effective bonding for plates: No. 25, which had a low bonding temperature of 600°C, but was successfully bonded because the mating material was ferrite; and No. 26, where the bonding temperature was too low and no bonding force was produced. Examples No. 29 and No. 30 are inferior to No. 27 and 28 because they do not contain Mitsushi Metal. As can be seen from Table 2, the chemical components within the scope of the present invention and the adhesive paste in powder form can provide a good bonding state even when coated on one side if used in an appropriate manner. In addition, in each of the above examples, regarding heat resistance,
It was confirmed that the joint could withstand up to the joining temperature. Example 3 20g of Ti powder, 40g of Ag powder, and 40g of Cu powder were mixed with powders of each component, each of which has a powder size of 325 mesh or less.
The mixture was mixed in a proportion of 40 g, mixed and crushed in a crusher for about 3 hours, and then finely crushed to a particle size of 10 μm or less to obtain a composite powder. Next, the following proportions were blended to make a paste-like adhesive. The above mixed fine powder 100g Ethylcellulose 18.3g Texanol 20.8g Activator 2.2g 141.3g of this composition was pre-kneaded using a universal mixer, and then main-kneaded using a three-roll mill to form a paste. Next, using a test piece of the base material shown in Table 3 having the same dimensions as in Example 1, printing was performed on one side of the combined base material shown in the same table using a screen printer. The screen was made of 200 mesh stainless steel, bias tensioned, and had an emulsion thickness of 45 μm. After printing, level for 10 minutes at room temperature, and then
It was dried at 105°C for 30 minutes. After drying, degreasing was performed using a film thickening oven in a nitrogen stream at a peak temperature of 600° C. for 8 minutes for 60 minutes. Next, the base materials were overlapped and bonded under vacuum or in a nitrogen stream under a load of 0.5 Kg/cm ² . In the example of the present invention, the bonding conditions are as follows: heating at 10 ^-4 Torr for 850°C x 1 hr in a vacuum, and heating at 850°C for 1 hr in a nitrogen stream, and using a thick film firing furnace to reach the peak temperature.
Heated at 850°C x 15 minutes profile for 90 minutes. After bonding, the bonding strength was examined in the following manner, and the bonding strength after the heat resistance test was also examined. The results were as shown in the same table. To measure the bonding strength, first, a 10mm-sized bonded sample was cut using a MEEK processing machine, and this was set as shown in Figure 3, and the bonding strength was measured using a push pull tester (manufactured by Imada Seisakusho). In addition, in the figure, 1 and 2 are base materials adhered with the bonding layer 3, and one base material 1 is coated with Araldite AZ-
Stainless steel plate 4 (SUS304, 20mm x
50mm
φ) was glued. For judgment of bonding strength, cases in which the graphite base materials were not bonded at all were indicated by a - mark, and cases in which the graphite substrates were broken at the bonded surface were indicated by the load at the time of breakage. However, if there was no abnormality at all on the joint surface and the copper rivet broke, the tester's allowable load of 150 kg was used and it was indicated as "150 kg or more." In the heat resistance test, the bonding test piece was held at 900° C. for 1 hour in N ₂ and then taken out, and the state of peeling was observed. Cases in which no peeling was observed are indicated by a circle in the table.

[Table] As shown in Table 3, in all of the invention examples, there was no abnormality at all on the bonded surfaces, the copper rivets were broken, and the bonding strength was sufficient and was strong enough to withstand use at 150 kg or more. On the other hand, if the degreasing temperature is too high (No. 43) or the bonding temperature is too low (No. 44), bonding becomes impossible and the film thickness after degreasing is too thin (No. 45).
Or, if it was not degreased (No. 46), the bonding strength was insufficient. In particular, in Comparative Example No. 46, which was not degreased, air bubbles were generated in the adhesive layer. As is clear from this example, in the past, when bonding graphite together, adhesives other than pitch or tar could not be used;
In the case of bonding with ceramics and metals other than graphite, there were no suitable adhesives at all due to graphite's own lubricity and poor wettability. For example, even base material combinations such as graphite and graphite, graphite and other ceramics, graphite and metal, etc. can be easily joined. In particular, bonding graphite to metal can be easily achieved by bonding objects with extremely complex shapes, and bonding graphite and metal can be applied to manufacturing sliding parts, heat dissipation blocks, linings, etc. using lubricity. Furthermore, the bonding of graphite and other ceramics can be applied to the production of sliding members utilizing lubricity, members utilizing wear resistance, heat resistant materials, corrosion resistant materials, etc. (Effects of the Invention) As detailed above, the adhesive paste according to the present invention has its chemical composition adjusted using a specific component system, and the powder form is made into a composite powder into a paste form, so that it is easy to bond and is heat resistant. It is possible to obtain joints with excellent properties and adhesive strength, and it can be used not only for joining the same materials such as metals and ceramics, but also for joining different materials. In particular, since it is in the form of a paste, it can be applied by a printing process and can be processed in large quantities.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the composition range of the composite powder in the adhesive paste of the present invention, Fig. 2 a to f are diagrams explaining the particle structure of the composite powder in the present invention, and a and b are SEM photographs showing the particle structure. , c to e are SEM-
EDX photograph, f is an X-ray diffraction diagram, Figure 3 is a diagram explaining the adhesive strength measurement method of the bonding layer, Figure 4 a-
f is a diagram explaining the particle structure of the mixed powder, a and b are SEM photographs showing the particle structure, and c to e are SEM-
EDX photograph, f is an X-ray diffraction diagram.

Claims (1)

[Claims] 1% by weight (the same applies hereinafter), containing 10 to 60% of at least one of Cu and Ni, 10 to 80% of at least one of Ti, Nb and Zr, and the remainder A composite powder, which has a composition in which Ag is substantially 10 to 80%, and in which each component particle is mechanically intertwined in a layered manner by a mechanical alloying method and alloyed in a solid state, is processed during organic sifting. An adhesive paste characterized by being dispersed into a paste form. 2 At least one of Cu and Ni 10 to 60
%, at least one of Ti, Nb and Zr.
~80%, contains at least one rare earth element (including Y) at 5ppm~3%, and the remainder is substantially
A composite powder with a composition of 10 to 80% Ag, in which each component particle is mechanically intertwined in layers using a mechanical alloying method and alloyed in a solid state, is dispersed in an organic solvent to form a paste. An adhesive paste characterized by: