JP6266918B2 - Joined body of ceramic body and Ni-Cr-Fe alloy, and joining method of ceramic body and Ni-Cr-Fe alloy - Google Patents

Description

  The present invention relates to a joined body between a ceramic body and a metal body, and a joining method between the ceramic body and the metal body.

  As a method of joining a ceramic body such as a ceramic substrate and a metal body such as a metal substrate, for example, as described in Patent Document 1 below, the ceramic body and the metal are interposed via a metal layer containing an active metal such as Ti. An active metal method for joining the body has been conventionally used. As a typical active metal method, there is a method using a metal layer (Ag—Cu—Ti metallized layer) containing Ag, Cu and Ti.

JP-A-2-252682

  However, when the joined body joined by the active metal method using the Ag-Cu-Ti metallized layer is disposed in a high-temperature atmosphere higher than 800 ° C., for example, the joining strength between the ceramic body and the metal body is lowered. There was a problem.

  In the active metal method using an Ag—Cu—Ti metallization layer, Ag and Cu form a eutectic in the metallization layer. The temperature at which Ag and Cu form a eutectic (eutectic point) is about 780 ° C., and the Ag—Cu—Ti metallized layer is obtained by baking a paste containing Ag, Cu, and Ti at a temperature of about 800 ° C. Is formed. When a joined body joined by an active metal method using this Ag—Cu—Ti metallized layer is placed in a high temperature atmosphere higher than 800 ° C., for example, the eutectic state of Ag and Cu changes, and this Ag and Cu The eutectic with Cu partially melts and the metallized layer deteriorates. This is considered to be the cause of the decrease in the bonding strength between the ceramic body and the metal body. As described above, since the bonding between the ceramic body and the metal body is deteriorated in a high temperature atmosphere and the bonding strength is easily lowered, there is a problem that it is difficult to use at a high temperature. The present invention aims to solve such a problem.

In order to solve the above problems, the present invention is a joined body of a ceramic body and a Ni-Cr-Fe alloy, wherein the ceramic body and the metal body are mainly composed of Ag, Cu, Ti, Ni Further, the ceramic body is bonded through a bonding layer containing Cr, and a portion of the bonding layer in contact with the Cr-Ni-based alloy contains Cu containing Ag as a main component. And a Ni—Cr—Fe alloy joined body.

  Even when the joined body of the ceramic body and the metal body of the present invention is disposed in a high temperature atmosphere of, for example, 800 ° C. or higher, the joint strength can be kept relatively high.

(A) And (b) is a schematic sectional drawing explaining one Embodiment of the joined body of the ceramic body and metal body of this invention, (a) is a general view, (b) is one of (a). The part (area A shown in FIG. 1 (a)) is shown enlarged. (A)-(e) is a schematic sectional drawing in one Embodiment of the joining method of the ceramic body and metal body of this invention. (A) is the photograph (cross-sectional SEM photograph) obtained by observing the cross section of one Embodiment of the joined body of the ceramic body and metal body of this invention with a scanning electron microscope. Moreover, (b)-(f) is a figure which shows the distribution state of the element in the said cross section measured when acquiring the cross-sectional SEM photograph shown to (a), (b) is distribution of Ag, (c). Is a Cu distribution, (d) is a Ti distribution, (e) is a Cr distribution, and (f) is a Ni distribution. It is a graph which shows the change of the joint strength before and behind heat processing in one Embodiment of the joined body of a ceramic body and a metal body.

  Hereinafter, the joined body of the ceramic body and the metal body and the joining method of the present invention will be described in detail. 1A and 1B are schematic cross-sectional views of a joined body 10 as an embodiment of a joined body of a ceramic body and a metal body according to the present invention, where FIG. 1A is an overall view, and FIG. The area A shown in FIG.

The joined body 10 of the present embodiment is a joined body of a ceramic body 12 and a metal body 14, and the ceramic body 12 and the metal body 14 contain Ag as a main component and contain Cu, Ti, Ni, and Cr. Bonded via the bonded layer 16. The ceramic body 12 contains, for example, Al ₂ O ₃ as a main component. Ceramic body 12 of this embodiment is a plate-like member mainly composed of for example, Al ₂ O _3, there is no particular limitation on the material and shape of the ceramic body of the present invention. The metal body 14 is a plate-like member whose main component is, for example, an alloy (so-called inconel) containing 76% Ni, 16% Cr, and 8% Fe. It is known that this alloy (Inconel) has high heat resistance and is not easily oxidized even at a high temperature of, for example, 900 ° C. or higher. The ceramic body 12 is a ceramic mainly composed of alumina. Alumina is a ceramic that is relatively inexpensive and has high heat resistance, and is often used as a material for members used in a high-temperature environment of 1000 ° C. or higher, such as a furnace wall of a firing furnace or a single crystal manufacturing apparatus furnace.

  The joined body 10 has, for example, the mechanical durability of the ceramic body and the electrical conductivity of the metal body, such as an electrode member of a sensor disposed in a diesel engine. It is a member used for a portion where the temperature is raised to about 800 ° C to 900 ° C.

In the present embodiment, in the bonding layer 16 of the bonded body 10, a first titanium layer 22 mainly composed of Ti that is in contact with the ceramic body 12, and closer to the metal body 14 than the first titanium layer 22. A first intermediate layer 32 containing Cu as a main component and containing Cu, and Ti arranged closer to the metal body 14 than the first intermediate layer 32 and arranged away from the first titanium layer 32. Nickel containing Ni and Cr, which is disposed at least closer to the metal body 14 than the second titanium layer 24 and is in contact with the second titanium layer 24. A chromium layer 26; Note that the bonding layer 16 may be a stack of a plurality of layers or a single layer. When Ag is the main component, Ag may be 50 mass% or more in the entire bonding layer 16. The element content and distribution in the bonding layer 16 can be measured using, for example, a known EDS (Energy Dispersive X-ray Spectroscopy) apparatus. For example, analysis may be performed under the condition of an acceleration voltage of 15 kV using an EDZ analyzer JED-2300 manufactured by JEOL. The bonding layer 16 of the present embodiment includes, for example, 88.6% by mass of Ag, 8.6% of Cu, 5% by mass of Ti, 1.25% by mass of Cr, and 5% by mass of Ni. The content ratios of Ag, Cu, Ti, Cr, and Ni in the bonding layer are, for example, 60 to 95 mass% for Ag, 1 to 5 mass% for Cu, 1 to 10 mass% for Ti, and 0.2 to 5 mass% for Cr. %, Ni is preferably about 3 to 10% by mass.

The first titanium layer 22 is a layer formed by diffusing Ti, which is an active metal that contributes to bonding, and concentrating on the ceramic body 12 side. The first titanium layer 22 includes a ceramic body 12 mainly composed of Al ₂ O ₃ and Bonded with high strength. The bonding layer 16 has the first titanium layer 22 bonded to the ceramic body 12 with high strength, so that the bonding layer 16 is bonded to the surface of the ceramic body 12 that originally has low wettability with metal with relatively high strength. . The first intermediate layer 32 is disposed between the first titanium layer 22 and the second titanium layer 24, and contains a eutectic of Ag and Cu. The first intermediate layer 32 is bonded to the first titanium layer 22 containing Ti as a main component and the second titanium layer 24 also containing Ti as a main component with high strength. The second titanium layer 24 is a layer formed by collecting a part of Ti which is an active metal that did not diffuse to the ceramic body 12 side (which did not contribute to direct bonding with the ceramic body 12). .

  Ti is relatively easy to oxidize, and easily fragile when oxidized. When oxygen taken into the bonding layer 16 in the process of forming the bonding layer 16 touches the second titanium layer 24, the second titanium layer 24 is oxidized and the second titanium layer 24 becomes brittle. In the joined body 10 of the present embodiment, the nickel-chromium layer 26 containing Ni and Cr in contact with the second titanium layer 24 suppresses the contact between the second titanium layer 24 and oxygen molecules. Are difficult to oxidize, and even when the bonded body 10 is placed in a relatively high temperature atmosphere, the second titanium layer 24 is unlikely to become brittle. In the embodiment shown in FIG. 1, the nickel-chrome layer 26 is disposed only on the side closer to the metal body 14 than the second titanium layer 24, but also on the side closer to the ceramic body 12 than the second titanium layer 24. Another layer may be disposed so as to sandwich the second titanium layer 24. When the nickel-chromium layer 26 is disposed so as to sandwich the second titanium layer 24, the oxidation of the second titanium layer 24 can be further suppressed. Further, the nickel-chromium layer 26 contains Cu, and the bonding strength with the first intermediate layer 32 containing Cu is high.

  Further, the bonding layer 16 further includes a second intermediate layer 34 which is disposed between the second titanium layer 24 and the metal body 14 and contains Cu containing Ag as a main component. The second intermediate layer 34 containing Ag as a main component and containing Cu has high bonding strength with the second titanium layer 24 and high bonding strength with the metal body 14.

  Since each layer constituting the bonding layer 16 has high bonding strength with the adjacent layers that are in contact with each other, in the metal body 10, the ceramic body 12 and the metal body 14 are bonded relatively firmly via the bonding layer 16. . In addition, since the nickel-chromium layer 26 containing Ni and Cr suppresses the contact between the second titanium layer 24 and oxygen molecules, the oxidation of the second titanium layer 24 is suppressed even when placed in a high temperature atmosphere. Thus, the second titanium layer 24 itself is suppressed from becoming brittle. For this reason, even if it is a case where it arrange | positions in the high temperature atmosphere higher than 800 degreeC, for example in the joining layer 16, the joining strength of the ceramic body 12 and the metal body 14 can be kept comparatively high. The joined body 10 is used in various high temperature environments such as a sensor member used for optimizing the fuel efficiency of a diesel engine, a thermoelectric converter that converts exhaust heat from an engine, a boiler, and the like into electric energy. It can be used as part of a type of device and its use is not limited.

  The joined body 10 of this embodiment can be manufactured by the method shown below, for example. 2A to 2E are schematic cross-sectional views illustrating an embodiment of a method for joining a ceramic body and a metal body according to the present invention.

For example, a ceramic body 12 having Al ₂ O ₃ as a main component is prepared, and a paste in which a powder containing Ag, a Cu, Ti, and Cr mixture and a firing aid is mixed is applied to the surface of the ceramic body. Apply. Specifically, for example, a predetermined amount of Ag powder, Cu powder, Ti powder, and Cr powder are weighed, and a vehicle in which a binder such as ethyl cellulose is dissolved in an organic solvent such as terpineol and the above powder are mixed with a mixer. And create a paste. Next, this paste is applied to a predetermined portion of the surface of the ceramic body 12 by a known method such as a screen printing method to form a paste layer 42 as shown in FIG. For example, Ag, Cu, Ti, and Cr powders may be mixed such that Ag is 88% by mass, Cu is 5% by mass, Ti is 5% by mass, and Cr is 2% by mass. If each powder of Ag, Cu, Ti and Cr is, for example, Ag is 70 to 98% by mass, Cu is 1 to 5% by mass, Ti is 1 to 10% by mass, and Cr is about 0.2 to 5% by mass. preferable.

  The ratio of Ag, Cu, and Ti of a paste used for general so-called Ag—Cu—Ti metallization is, for example, about 70% by mass for Ag, 20% by mass for Cu, and about 10% for Ti. In the present embodiment, a paste further added with Cr is used for a paste used for general Ag—Cu—Ti metallization. In addition, the Cu content is relatively small with respect to the paste used for general Ag-Cu-Ti metallization.

Next, the applied paste (paste layer 42) is fired, and a metal film 44 containing Ag as a main component and containing Cu, Ti, and Cr on the surface of the ceramic body 12 as shown in FIG. 2B. Form. More specifically, the metal film 44 is formed by performing heat treatment at about 1100 ° C. for 15 minutes in a vacuum atmosphere of about 1.0 × 10 ⁻⁵ Pa. In the metal film 44, Ag and Cu form a eutectic. The melting point of Cu is about 1080 ° C., and when the heat treatment is performed by raising the temperature to 1100 ° C. when forming a normal Ag—Cu—Ti metallized layer, the molten Cu is likely to diffuse into the porcelain. In this embodiment, Cr is further contained in addition to Ag, Cu, and Ti, and the diffusion of Cu is suppressed by the action of Cr. Although it is not clear about the effect | action of Cr, not only the Ag-Cu eutectic whose eutectic point mainly formed in the conventional Ag-Cu-Ti metallization layer is about 800 degreeC but Ag-Cu-Cr or It can be presumed that diffusion of Cu is suppressed by forming a high melting point liquid phase such as Ag-Cu-Cr-Ti.

  Next, as shown in FIG. 2C, a nickel plating layer 46 containing Ni as a main component is formed on the surface of the metal film 44. The nickel plating layer 46 may be formed to a thickness of about 1 to 3 μm using a conventionally known method such as an electric field Ni plating method.

  Next, as shown in FIG. 2D, the metal body 14 is disposed on the surface of the nickel plating layer 46 via a brazing material 48 containing metal as a main component. Specifically, for example, an Ag brazing material 48 having a thickness of 0.6 mm and containing Ag as a main component is disposed on the nickel plating layer 46, and the metal body 14 is disposed thereon. As the Ag brazing material 48, for example, a material containing 95% by mass of Ag and 5% by mass of Cu may be used.

Next, in this state, the whole is heated to melt the brazing material 48, the nickel plating layer 46, and the metal film 44, and then the whole is cooled and solidified to obtain FIGS. 2 (e) and 1 (a). As shown in (b), a bonding layer 16 for bonding the ceramic body 12 and the metal body 14 is formed. Specifically, the whole is heated at about 1000 ° C. for 15 minutes in a vacuum atmosphere of about 1.0 × 10 ⁻⁵ Pa, and then the whole is lowered to room temperature to form the bonding layer 16.

By raising the temperature to 1100 ° C., the brazing material 48 containing Ag having a melting point of 961 ° C. as a main component and the metal film 44 also containing Ag as the main component are melted, and the brazing material 48 and the metal film 44 are melted. In addition, the components contained in the nickel plating layer diffuse in the molten layer, and the Ni component contained in the nickel plating layer 46 also diffuses in the molten layer. Ti contained in the metal film 44 is concentrated on the ceramic body 12 side to form the first titanium layer 22 and does not diffuse to the ceramic body 12 side of Ti (with the ceramic body 12). The second titanium layer 24 is formed by concentrating the portion that has not contributed to the direct bonding to the nickel plating layer 46 side (that is, the metal body 14 side). Further, Cr contained in the metal film 44 diffuses and reacts mainly with Ni contained in the Ni plating layer 46 to form a nickel-chrome layer 26 containing Ni and Cr. The Cu component contained in the metal film 44 diffuses throughout and is disposed between the first titanium layer 22 and the second titanium layer 24. The first intermediate layer 32 containing Cu as a main component of Ag, A second intermediate layer 34 containing Cu as a main component and disposed between the second titanium layer 24 and the metal body 14 is formed.

  As described above, by using the bonding method of the present embodiment, the first titanium layer 22 mainly composed of Ti that is in contact with the ceramic body 12 and at least the first titanium layer 22 closer to the metal body 14 than the first titanium layer 22. A second titanium layer 24 mainly composed of Ti, which is disposed apart from the titanium layer 22, and a Cu which is mainly composed of Ag and which is disposed between the first titanium layer 22 and the second titanium layer 24. The joining layer 46 which has the 1st intermediate | middle layer 32 and the nickel-chromium layer 26 which is arrange | positioned at least by the side close | similar to the metal body 14 rather than the 2nd titanium layer 24, and is in contact with the 2nd titanium layer 24. Can be formed.

  Even if the joined body of the ceramic body and the metal body manufactured by using the joining method of the present embodiment is disposed in a high temperature atmosphere higher than 800 ° C., for example, the ceramic body 12 and the metal body 14 The bonding strength can be kept relatively high.

Examples of the present invention will be described below, and examples of the effects of the present invention will be described. FIG. 3A is a photograph (cross-sectional SEM photograph) obtained by observing a cross section of the metallized substrate manufactured through the above-described steps with a scanning electron microscope. FIG. 3B is a diagram (EPMA elephant: Electron Probe Micro Analyzer elephant) showing a distribution state of Ag in the cross section measured when the cross-sectional SEM photograph shown in FIG. 3A is acquired. FIG. 3C is a diagram showing a Cu distribution state in the cross section, FIG. 3D is a diagram showing a Ti distribution state in the cross section, and FIG. 3E is a diagram showing Cr in the cross section. FIG. 3F is a diagram showing a Ni distribution state in the cross section. The scanning electron microscope was, for example, an S-800 manufactured by Hitachi and photographed at an acceleration voltage of 15 kV.

  As is clear from FIGS. 3A to 3F, the ceramic body 12 and the metal body 14 are formed via a bonding layer 16 containing Ag as a main component and containing Cu, Ti, Ni, and Cr. It is joined. The bonding layer 16 of the bonded body 10 includes a first titanium layer 22 mainly composed of Ti that is in contact with the ceramic body 12 and a first titanium layer 22 that is at least closer to the metal body 14 than the first titanium layer 22. A second titanium layer 24 mainly composed of Ti, which is disposed apart from the first titanium layer 22, and a first intermediate layer including Cu, which is mainly composed of Ag, disposed between the first titanium layer 22 and the second titanium layer 24. It can be seen that the layer 32 and the nickel-chromium layer 26 containing Ni and Cr are disposed at least on the side closer to the metal body 14 than the second titanium layer 24 and are in contact with the second titanium layer 24. As can be seen from FIG. 3D, in the present embodiment, the first titanium layer 22 and the second titanium layer 24 containing Ti as a main component are arranged so as to be partially connected. As described above, in the joined body of the present invention, it is not necessary that all of the inside of the joining layer have the same layer configuration, and a part thereof may be deformed.

  Next, the result of investigating the joining strength of the joined body of the ceramic body and the metal body as an example of the joined body of the present invention is shown below.

The investigation procedure and conditions were as follows. First, an Al ₂ O ₃ substrate of 30 mm × 30 mm × 1.5 mm was prepared as a ceramic body, and an Inconel (Ni—Cr—Fe alloy) substrate of 2 mm × 40 mm × 0.3 mm was prepared as a metal body. The joined body of Example 1 was obtained by joining the ceramic body and the metal body in the steps as shown in the above-mentioned Examples. Further, as a comparative example, a conventional Ag-C in which Cr is removed from a paste for forming a metal film.
A joined body (Comparative Example 1) using a paste for u-Ti metallization was obtained. In Comparative Example 1, a conventional paste for Ag—Cu—Ti metallization mixed so that Ag was 90% by mass, Cu was 5% by mass, and Ti was 5% by mass was used. A plurality of joined bodies of Example 1 and a joined body of Comparative Example 1 were prepared, and peel strength was measured for some of the joined bodies. Further, among the joined body of Example 1 and the joined body of Comparative Example 1, each of the joined bodies was subjected to a heat treatment that was placed in the air for 1 h while being heated to 800 ° C. The peel strength of each joined body was measured. The peel strength was measured by a method based on JIS-C5012.

  FIG. 4 is a graph showing the results of taking the average value of peel strength measured for a plurality of samples under each condition.

  As can be seen from the experimental results shown in FIG. 4, the joined body of Example 1 is higher than, for example, 800 ° C. or higher compared to the joined body using the paste for conventional Ag—Cu—Ti metallization (Comparative Example 1). Even when arranged in a high-temperature atmosphere, the bonding strength can be kept relatively high as compared with the prior art.

  While the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples. It goes without saying that various improvements and modifications may be made to the present invention without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 Joining body 12 Ceramic body 14 Metal body 16 Joining layer 22 1st titanium layer 24 2nd titanium layer 26 Nickel-chromium layer 32 1st intermediate layer 34 2nd intermediate layer 44 Metal film 46 Nickel plating layer

Claims (8)

A joined body of a ceramic body and a Ni—Cr—Fe alloy,
The ceramic body and the Ni-Cr-Fe alloy are bonded via a bonding layer containing Ag as a main component, Cu, Ti, Ni, and Cr.
The bonding layer is a bonded body of a ceramic body and a Ni-Cr-Fe alloy, wherein a portion in contact with the Ni-Cr-Fe alloy contains Cu containing Ag as a main component. The bonding layer is
2. The joined body of a ceramic body and a Ni—Cr—Fe alloy according to claim 1, which has a portion where Ni and Cr are overlapped and confirmed in an element distribution state by EPMA measurement in the same cross section. The bonding layer is
3. The bonding of a ceramic body and a Ni—Cr—Fe alloy according to claim 2, characterized in that, in the element distribution state by EPMA measurement in the same cross section, there is a portion where Cu is confirmed in addition to Ni and Cr. body. 4. The bonded body of a ceramic body and a Ni—Cr—Fe alloy according to claim 1, wherein a portion of the bonding layer in contact with the ceramic body contains Ti as a main component. 5. The ceramic body is bonded body of the ceramic body and the Ni-Cr-Fe alloy as claimed in any one of claims 1 to 4, characterized in that a main component _Al 2 _{O 3.} An application step of applying a paste in which Ag is a main component, Cu, Ti and Cr are mixed and a vehicle is mixed to the surface of the ceramic body;
A firing step of firing the applied paste to form a metal film containing Ag as a main component, Cu, Ti, and Cr on the surface of the ceramic body;
A plating step of forming a nickel plating layer mainly composed of Ni on the surface of the metal film;
Disposing a Ni-Cr-Fe alloy on the surface of the nickel plating layer through a brazing material containing metal as a main component;
Heating the whole with the Ni—Cr—Fe alloy disposed on the brazing material to melt the brazing material, the nickel plating layer, and the metal film;
After the step of melting, the whole is cooled to join the ceramic body and the Ni—Cr—Fe alloy, and a joining layer containing Ag, Cu, Ti, Ni, and Cr as a main component is formed. A method of joining the ceramic body and the Ni—Cr—Fe alloy. 7. The method for joining a ceramic body and a Ni—Cr—Fe alloy according to claim 6, wherein in the firing step, the paste is fired at a temperature of 900 ° C. or higher. The said brazing material has Ag as a main component and contains Cu, The joining method of the ceramic body and Ni-Cr-Fe alloy of Claim 6 or Claim 7 characterized by the above-mentioned.