JP2016037422A - Joining material and use thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining material containing no alkali component, capable of airtightly encapsulating a junction between components having different coefficients of thermal expansion (for example, between a ceramic component and a metallic component) for a long period.SOLUTION: Provided is a joining material 10 comprising a laminated glass composed of three or more glass layers and, in a direction of lamination of the glass layers, a coefficient of thermal expansion of the glass layers in a range of 30°C to 500°C increases gradually from a glass layer at one end of the glass layers (glass layer 12 having the least coefficient of thermal expansion) towards a glass layer at the other end of the glass layers (glass layer 16 having the largest coefficient of thermal expansion). A difference in coefficients of thermal expansion between neighboring glass layers of the joining material 10 in a range of 30°C to 500°C is each 1.5 ppm/K or less. Further, in each glass layer, an alkali component is not contained.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bonding material. Specifically, the present invention relates to a bonding material that can be suitably used for bonding between members having greatly different coefficients of thermal expansion (bonding of a ceramic member and a metal member).

In recent years, there has been a demand for members that can be exposed to harsh atmospheres (for example, high temperatures of about 100 ° C. to 200 ° C., strong acid, and strong alkali) such as automotive parts, semiconductor devices, and environmental devices. The properties to be achieved (for example, resistance and durability) are becoming stricter. In connection with this, the situation where metal materials, such as stainless steel and a special alloy which were conventionally used for this kind of application, is corroded. For this reason, use of a ceramic material (for example, alumina (Al ₂ O ₃ )) excellent in heat resistance, chemical stability, and the like has been studied. However, since the ceramic material is a brittle material and is also a difficult-to-process material, it is difficult to create a member having a complicated shape or a large shape. For this reason, such a member is constructed by joining and combining parts made of a ceramic material and parts made of a metal material.
Conventionally, for joining ceramic members, as a bonding material, for example, the thermal expansion coefficient is approximately the same as the ceramic material constituting the ceramic member (for example, the thermal expansion coefficient at 30 ° C. to 500 ° C. is 6 ppm / K to 8 ppm / K). Glass bonding material (see Patent Document 1), metal materials having a slightly lower thermal expansion coefficient than that, and typically Kovar metal having a thermal expansion coefficient of approximately 6 ppm / K.

JP-A-5-85844 JP 2003-55034 A

However, Kovar metal has a problem that it can be used only for special purposes because of its low distribution and high price. In addition, the thermal expansion coefficient of the metal member at 30 ° C. to 500 ° C. is generally 10 ppm / K or more, and the thermal expansion coefficient is greatly different from that of the ceramic member. For this reason, when a conventional bonding material is used for bonding the ceramic member and the metal member, defects such as cracks and peeling may occur by repeating the heat cycle over a long period of time, for example. Accordingly, there is a demand for a bonding material that can hold a bonded portion between members having greatly different thermal expansion coefficients in an airtight manner over a long period of time.
In addition, in recent years, efforts to use inexpensive metal materials (for example, stainless steel, copper, aluminum, etc.) without film treatment (surface treatment) have been promoted in the industrial world due to cost reduction. In connection with this, the alkali component (for example, potassium (K) and sodium (Na)) contained in a glass bonding material may become a problem. That is, the alkali component is useful for imparting fluidity to the glass to lower the softening point and adjust the coefficient of thermal expansion. On the other hand, when used for a joint of the inexpensive metal material, It may react with a metal material (for example, chromium (Cr) component) in a high temperature range of not lower than 0 ° C. to cause a decrease in stability of the joint (for example, a decrease in adhesion and a decrease in durability). Moreover, it is feared that the above reaction produces a highly toxic hexavalent chromium compound. Under such circumstances, there is a demand for a bonding material that does not contain an alkali component (alkali-less) depending on, for example, the type of member to be bonded, the environment in which the bonded body is used, the application, and the like.

  The present invention has been made in view of such circumstances, and an object thereof is a bonding material that does not contain an alkaline component, and firmly bonds between members having different thermal expansion coefficients (for example, between a ceramic member and a metal member). Another object of the present invention is to provide an alkali-less bonding material that can be used and can realize a bonded portion having high durability (particularly, heat cycle resistance). Another related object is to provide a joined body provided with a joined portion using such a joining material.

  The bonding material disclosed here is for bonding members having different thermal expansion coefficients. Such a bonding material is composed of three or more glass layers, and heat of 30 ° C. to 500 ° C. from the glass layer at one end toward the glass layer at the other end in the stacking direction of the glass layers. It is a laminated glass whose expansion coefficient increases stepwise, and the difference in thermal expansion coefficient at 30 ° C. to 500 ° C. between the adjacent glass layers is 1.5 ppm / K or less. And neither glass layer contains an alkali component.

  By making the bonding material have a laminated glass structure of three or more layers and changing the thermal expansion coefficient between adjacent glass layers in stages, the bonding material (bonding portion) can be given a gradient of thermal expansion coefficient. Thereby, the difference of the thermal expansion coefficient between the members from which a thermal expansion coefficient differs can be relieve | moderated. As a result, these members can be firmly bonded, and high heat resistance, chemical stability, and durability can be imparted to the bonded portion. Furthermore, since none of the glass layers contains an alkali component, for example, when a ceramic member and a chromium-based metal member are joined and used in a high temperature environment, the joint between both members is high for a long period of time. Airtightness and mechanical strength can be maintained. That is, it is possible to stably realize a joint having excellent reliability and durability (long-term high-temperature durability).

In this specification, “thermal expansion coefficient” refers to an average expansion coefficient (average linear expansion coefficient) measured in a temperature range from 30 ° C. to 500 ° C. with a general thermomechanical analyzer (TMA). The value obtained by dividing the amount of change in the sample length with respect to the initial length of the sample by the temperature difference. The measurement of the thermal expansion coefficient can be performed according to JIS R 3102 (1995). Further, in the present specification, “not containing an alkali component” means that the component is not added at least actively. In other words, as an unavoidable impurity or the like, for example, at a ratio of about 1% by mass (typically 0.1% by mass or less, preferably 0.01% by mass or less) of the entire bonding material (laminated glass). Ingredients can be allowed to enter.
Patent Document 2 is given as a prior art document regarding a laminated glass-ceramic material.

In a preferred embodiment of the bonding material disclosed herein, the thermal expansion coefficient of the entire laminated glass at 30 ° C. to 500 ° C. is 5 ppm / K or more and 20 ppm / K or less.
Thereby, for example, a member having a thermal expansion coefficient of 30 to 500 ° C. of about 6 ppm / K to 8 ppm / K and a member having a thermal expansion coefficient of 30 to 500 ° C. of about 10 ppm / K to 23 ppm / K Can be suitably joined.

In a preferred embodiment of the bonding material disclosed herein, the three or more glass layers are each independently one or more of Ba, Si, Al, Ti, Zn, B, and Ca. Contains oxides of the elements.
The oxides of these elements can be useful for adjusting the thermal expansion coefficient of each glass layer and controlling various properties such as stability. Therefore, the effect of the present invention can be exhibited at a higher level.

In one preferred embodiment of the bonding material disclosed herein, overall the laminated glass, the mass ratio of the oxide conversion, BaO: 50-65 _wt%, SiO 2: 20 to 35 _wt%, Al _{2 O} 3: 5-15 _wt%, TiO 2: _1~10 wt%, ZnO: 0 to 5 _{wt%, B} 2 O 3: 1~5 wt%, MgO, CaO and at least one of SrO: 1 to 5 mass % Component.
By setting it as such a composition, at least 1 can be improved among heat resistance, chemical stability, and durability. Furthermore, the range of the thermal expansion coefficient can be suitably realized, and the effects of the present invention can be exhibited at a higher level.

In a preferred aspect of the bonding material disclosed herein, the glass layer at the one end has a thermal expansion coefficient at 30 ° C. to 500 ° C. of 6 ppm / K or more and 8 ppm / K or less, and the other end. The thermal expansion coefficient at 30 ° C. to 500 ° C. of the glass layer is 10 ppm / K or more and 16 ppm / K or less.
Thereby, for example, a member having a thermal expansion coefficient of about 6 ppm / K to 8 ppm / K at 30 ° C. to 500 ° C. and a member having a thermal expansion coefficient of about 10 ppm / K to 15 ppm / K at 30 ° C. to 500 ° C. is firmly joined. It is possible to form a joint having excellent durability.

  The bonding material disclosed herein is preferably used particularly for bonding between different parts having different thermal expansion coefficients (for example, different thermal expansion coefficients of 4 ppm / K or more), for example, bonding between a ceramic member and a metal member. In addition, the joint can be stably maintained in a high airtight state for a long time even in a high temperature range. Therefore, as another aspect of the present invention, there is provided a joined body including a ceramic member, a metal member, and a joint portion that joins the two members.

  In a preferred aspect of the joined body disclosed herein, the ceramic member is made of a ceramic material having a thermal expansion coefficient of 30 ppm to 500 ° C. of 6 ppm / K or more and 8 ppm / K or less. Examples of such a ceramic member include alumina-based ceramics. Moreover, the said metal member is comprised with the metal material whose thermal expansion coefficient of 30 to 500 degreeC is 10 ppm / K or more and 23 ppm / K or less. An example of such a metal member is stainless steel.

It is sectional drawing which shows typically one form of joining material (laminated glass).

  Hereinafter, preferred embodiments of the present invention will be described. Note that matters other than matters specifically mentioned in the present specification and necessary for the implementation of the present invention can be grasped as design matters of those skilled in the art based on the prior art in this field. The present invention can be carried out based on the contents disclosed in this specification and common technical knowledge in the field.

≪Bonding material≫
The bonding material (glass bonding material) disclosed herein is a bonding material for bonding two or more members having different thermal expansion coefficients, for example, between ceramic members, between metal members, or between a ceramic member and a metal member. It is. Such a bonding material is a laminated glass composed of three or more glass layers having different thermal expansion coefficients in stages (typically in steps). In other words, it is composed of three or more glass layers, and in the stacking direction of the glass layers, the thermal expansion coefficient increases stepwise from the glass layer at one end toward the glass layer at the other end. Laminated glass. A difference in thermal expansion coefficient between two adjacent glass layers (hereinafter, “difference in thermal expansion coefficient between two adjacent glass layers” may be simply referred to as “difference in thermal expansion coefficient”). Is also 1.5 ppm / K or less.
According to such a configuration, for example, from a glass layer having a relatively small thermal expansion coefficient (a glass layer having a small thermal expansion coefficient) to a glass layer having a relatively large thermal expansion coefficient (a glass layer having a large thermal expansion coefficient), The thermal expansion coefficient can be gradually changed (increased). Then, the glass material side of the bonding material having a large thermal expansion coefficient is brought into contact with a member to be bonded (for example, a metal member) having a relatively large coefficient of thermal expansion, and the glass material side of the bonding material having a small coefficient of thermal expansion is relatively heated. It is possible to match the thermal expansion coefficient of a member having a small thermal expansion coefficient and a member having a large thermal expansion coefficient by bringing the member into contact with a member to be joined (for example, a ceramic member) having a small expansion coefficient and joining the two members. it can. As a result, even when the heat cycle is repeated in a normal temperature range to a high temperature range, for example, it is difficult for thermal stress to be generated in the joint portion, and generation of residual stress can be suppressed. That is, a joint having excellent heat cycle resistance can be realized.

  In the technique disclosed herein, the difference in thermal expansion coefficient between two adjacent glass layers of the bonding material (laminated glass) is 1.5 ppm / K or less, typically 1.4 ppm / K or less, for example, 0 It is good that they are 5 ppm / K or more and 1.4 ppm / K or less. By setting the difference in thermal expansion coefficient to 1.4 ppm / K or less, higher heat cycle resistance can be realized. Further, if the difference in thermal expansion coefficient is 0.5 ppm / K or more, the number of glass layers to be laminated can be reduced, which is preferable from the viewpoint of workability and cost.

The specific thermal expansion coefficient of each glass layer constituting the bonding material (laminated glass) is not particularly limited because it may vary depending on the thermal expansion coefficient of the members to be bonded. Typically, the thermal expansion coefficient of each glass layer is equal to or higher than the thermal expansion coefficient of one bonded member (for example, approximately 5 ppm / K or higher) and is equal to or lower than the thermal expansion coefficient of the other bonded member (for example, About 23 ppm / K or less).
In a preferred embodiment, the glass layer at one end (the small thermal expansion coefficient glass layer) has a thermal expansion coefficient comparable to or slightly lower than that of the ceramic member, and the glass layer at the other end. The thermal expansion coefficient of the (thermal expansion coefficient large glass layer) is the same as or slightly lower than the thermal expansion coefficient of the metal member. For example, the thermal expansion coefficient of the glass layer having a small thermal expansion coefficient is 6 ppm / K or more and 8 ppm / K or less (for example, 6.0 ppm / K or more and 7.9 ppm / K or less), Is 10 ppm / K or more and 16 ppm / K or less (for example, 11.6 ppm / K or more and 15.0 ppm / K or less). According to this aspect, for example, an alumina-based ceramic member (thermal expansion coefficient is approximately 10 ppm / K to 15 ppm / K) and a general-purpose stainless steel (thermal expansion coefficient is approximately 6 ppm / K to 8 ppm / K) as a metal member, Can be bonded firmly, and a bonded portion with excellent physical stability and durability can be realized.
In another preferred embodiment, the thermal expansion coefficient of the entire bonding material (laminated glass) is 5 ppm / K or more and 20 ppm / K or less. Such a joining material joins a member having a thermal expansion coefficient of 6 ppm / K to 8 ppm / K and a member having a thermal expansion coefficient of 10 ppm / K to 23 ppm / K (for example, the ceramic member and the metal member). Therefore, it can be used suitably.

The glass matrix (glass composition) constituting each glass layer of the bonding material (laminated glass) disclosed herein is not particularly limited except that it does not substantially contain an alkali component, and is optional according to various applications. Can be determined.
In a preferred embodiment, each glass layer contains a barium component, a silicon component, and an aluminum component. By including these three components in all the glass layers, there is an effect of improving the integrity and physical stability as laminated glass. From such a viewpoint, in particular, the total of the barium component, silicon component, and aluminum component in the glass matrix of each glass layer is preferably 80% by mass or more (for example, 85% by mass or more).

  The barium component (typically, barium oxide (BaO)) is a component for adjusting the thermal expansion coefficient of each glass layer and improving the thermal stability of the glass matrix. The ratio of the barium component in the glass matrix of each glass layer is not particularly limited as long as the range of the difference in thermal expansion coefficient is realized, but is approximately 20% by mass or more (for example, 25% by mass) in terms of an oxide-converted mass ratio. Or more) and 85% by mass or less (for example, 83% by mass or less).

A silicon component (typically, silicon oxide (SiO ₂ )) is a component constituting a skeleton of glass. The ratio of the silicon component in the glass matrix of each glass layer is not particularly limited as long as the range of the difference in thermal expansion coefficient is realized, but is approximately 5% by mass or more (for example, 10% by mass) in terms of an oxide-converted mass ratio. Or more) and may be 55% by mass or less (for example, 53% by mass or less). Thereby, it can prevent that the softening point of each glass layer becomes high too much, and it can join at a comparatively low temperature. Furthermore, at least one of water resistance, chemical resistance, and thermal shock resistance of a joint portion using the bonding material can be improved.

An aluminum component (typically aluminum oxide (Al ₂ O ₃ )) is a component that controls fluidity during melting of the glass matrix and participates in adhesion stability. The proportion of the aluminum component in the glass matrix of each glass layer is not particularly limited as long as the range of the difference in thermal expansion coefficient is realized, but is approximately 1% by mass or more (for example, 2% by mass) in terms of a mass ratio in terms of oxide. Or more) and may be 15% by mass or less (for example, 13% by mass or less). Thereby, it can prevent that the softening point of each glass layer becomes high too much, and it can join at a comparatively low temperature. Further, the members to be joined can be joined stably (homogeneously). Furthermore, the chemical resistance of the joint part using the said joining material can be improved.

  The glass matrix (glass composition) constituting each glass layer typically contains one or more optional additive components in addition to the barium component, silicon component, and aluminum component. Examples of such additive components include alkaline earth metal components in a broad sense other than Ba (for example, magnesium (Mg), calcium (Ca), strontium (Sr). In particular, calcium.), Zinc (Zn), titanium (Ti), boron (B), zirconium (Zr), vanadium (V), niobium (Nb), iron (Fe), copper (Cu), tin (Sn), phosphorus (P), lanthanum (La), cerium (Ce) and the like.

In a preferred embodiment, the glass matrix constituting each glass layer independently oxidizes one or more elements of Ti, Zn, B, and Ca in addition to Ba, Si, and Al. Contains things.
For example, a titanium component (typically titanium oxide (TiO ₂ )) is a component that can increase the thermal expansion coefficient. Thereby, the thermal expansion coefficient of the glass layer can be maintained at a relatively high value.
A zinc component (typically zinc oxide (ZnO)) is a component that has a high effect of improving the thermal stability of the glass frit. Furthermore, there is an effect that a chemically stable property and durability can be realized, such as high thermal shock resistance and being hardly attacked by water.
Further, the calcium component (typically calcium oxide (CaO)) is a component having a high effect of adjusting the thermal expansion coefficient and improving the thermal stability of the glass matrix, like the barium component. Furthermore, there is an effect that the hardness of the glass matrix can be increased and the wear resistance of the joint can be improved.
Further, the boron component (typically boron oxide (B ₂ O ₃ )) improves the thermal stability of the glass frit (adjusts the coefficient of thermal expansion) and reduces the softening point of the glass frit. Is a high component.
For this reason, the glass layer which is provided with the desired thermal expansion coefficient and excellent also in the various characteristics according to a use etc. is realizable by adjusting the component of the glass matrix which comprises each glass layer, and its content rate. .

  The components constituting each glass layer are typically 3 or more, for example, 4 or more and 10 or less. When the glass matrix is composed of a multi-component system having three or more components, physical stability is improved. From the viewpoint of workability and cost, the glass matrix is preferably composed of 10 components or less.

In a preferred aspect, at least one of the glass constituent elements (components) of one glass layer does not exist in the other glass layer between adjacent glass layers (hereinafter referred to as such element). Sometimes called “adjacent non-covalent elements”.) In other words, for each glass layer constituting the bonding material (laminated glass), at least one of the glass constituent elements (components) of one glass layer between at least one adjacent glass layer is the other glass. It may be configured not to exist in the layer. More preferably, each glass layer may be configured such that such glass layers are present continuously or intermittently (for example, every other or every second). For example, between any adjacent glass layers constituting the bonding material (laminated glass), at least one of the glass constituent elements of one glass layer is configured not to exist in the other glass layer. Also good. In addition, the kind of said adjacent non-covalent element may be the same between all the glass layers, and may differ.
According to the study of the present inventors, when the constituent components of the adjacent glass layers are exactly the same and only the mass ratio in terms of oxide is different, for example, the adjacent glass layers are mixed and homogenized. It is possible that The presence of adjacent non-covalent elements prevents the above-mentioned adjacent glass layers from being homogenized (typically, fusion during high-temperature firing), and can more stably ensure the gradient of the thermal expansion coefficient of the joint. . As a result, the joint portion between the members can be made stronger. Therefore, the effect of the present invention can be exhibited at a higher level.

In another preferred embodiment, the entire bonding material (laminated glass) is an oxide-converted mass ratio,
BaO 50-65 mass% (for example, 54-59 mass%),
SiO ₂ 20 to 35 wt% (e.g. 24 to 29 wt%),
Al ₂ O ₃ 5 to 15 wt% (e.g., 7-9 wt%),
TiO ₂ 1 to 10% by mass (eg 4 to 6% by mass),
ZnO 0-5 mass% (for example, 0-1 mass%),
B ₂ O ₃ 1 to 5 wt% (e.g., 1-3 wt%),
1-5 mass% (for example, 2-3 mass%) of at least 1 sort (s) of MgO, CaO, and SrO,
Contains ingredients. By making the whole glass matrix which comprises laminated glass into such a composition, stability of a junction part can be improved further and the effect of this invention can be exhibited at a still higher level.

Each glass layer of the bonding material (laminated glass) disclosed herein does not substantially contain an alkali component. In other words, an alkali component is not positively added to the glass matrix constituting each glass layer of the bonding material disclosed herein (mixing as an inevitable impurity can be permitted). Alkali components (for example, potassium component and sodium component) are likely to be scattered in a high-temperature environment, which may change the thermal expansion coefficient of the glass layer or decrease the mechanical strength. Further, as described above, for example, when a chromium-based metal material or an inexpensive metal material is used without a film treatment, the stability of the joint may be reduced by reacting with the metal material. For this reason, by not including an alkali component in any glass layer, for example, regardless of the type of a member to be joined (metal member) or the use environment of the joined body, the durability of the joined portion (long-term high temperature) A bonded body having high durability can be realized.
In addition, it is preferable that each glass layer does not contain an arsenic component (As) or a lead component (Pb). These components are not preferable from the viewpoints of environmental performance, workability, and safety because they can adversely affect the human body and the environment.

A preferred embodiment of the bonding material (laminated glass) disclosed herein is schematically shown in FIG. In the embodiment shown in FIG. 1, the bonding material 10 includes three glass layers having different thermal expansion coefficients, that is, an X layer (a small thermal expansion coefficient glass layer) 12, a Y layer (a medium thermal expansion coefficient glass layer) 14, and a Z layer ( It is a laminated glass having a three-layer structure composed of a glass layer having a large thermal expansion coefficient. The thermal expansion coefficients (ppm / K) of the three glass layers are in a relationship of X layer 12 <Y layer 14 <Z layer 16. Then, the difference in thermal expansion coefficient between the X layer 12 and the Y layer 14 (that is, (thermal expansion coefficient of the Y layer 14) − (thermal expansion coefficient of the X layer 12)), and the Y layer 14 and the Z layer 16 The difference in thermal expansion coefficient between (ie, (thermal expansion coefficient of Z layer 16) − (thermal expansion coefficient of Y layer 14)) is 1.5 ppm / K or less.
When the members to be joined are joined, the first surface 10a of the joining material (laminated glass) 10 is disposed so as to be in contact with a member having a relatively small thermal expansion coefficient. Further, the second surface 10b of the bonding material (laminated glass) 10 is disposed so as to be in contact with a member having a relatively large thermal expansion coefficient.

  The thickness of each glass layer (that is, the length in the vertical direction from the first surface 10a to the second surface 10b of the bonding material (laminated glass) 10) may be the same or different. In the embodiment shown in FIG. 1, the thicknesses of the X layer 12, the Y layer 14, and the Z layer 16 are substantially equal. In addition, the thickness of each glass layer is not particularly limited, but typically, the thickness of each glass layer is preferably several μm to several hundred μm, for example, about 1 μm to 100 μm. By setting the thickness of each glass layer to approximately 1 μm or more, the thermal expansion coefficient of the bonding material 10 can be stably and gradually changed from the first surface 10a toward the second surface 10b. For this reason, a more reliable joining part is realizable. Further, by setting the thickness of each glass layer to about 100 μm or less, it is possible to further suppress the occurrence of residual stress and to realize a joint portion that is further excellent in heat cycle resistance.

  In addition, in the aspect shown in FIG. 1, although the joining material 10 is comprised from 3 glass layers, it is not limited to this, For example, it may comprise from 4 glass layers or 5 or more glass layers. it can. The upper limit of the number of suitable glass layers is not particularly limited because it depends on, for example, the thickness of each glass layer, but in consideration of work efficiency, productivity, etc., typically 20 layers or less, for example, 10 layers or less. Good.

  The method for producing such a bonding material (laminated glass) is not particularly limited. For example, first, industrial products, reagents, oxides, carbonates, nitrates, composite oxides, and the like containing the components of each glass layer, Alternatively, various mineral raw materials are prepared and mixed so as to have a desired composition. The raw material powder can be prepared, for example, by putting the raw material into a mixer such as a ball mill and mixing for several hours to several tens of hours. After the glass raw material powder thus obtained is dried, the glass is prepared by heating and melting under high-temperature conditions (typically 1000 ° C. to 1500 ° C.), respectively, and cooling or quenching. In a preferred embodiment, the obtained glass is then sized appropriately (typically, the average particle size is about 0.5 μm to 50 μm. For example, the average particle size is about 0.1 μm to 10 μm). It grind | pulverizes until it becomes, and prepares in forms, such as glass cullet or glass powder. Next, after compression-molding the obtained glass (glass cullet and glass powder after pulverization), the glass is calcined at a temperature at which the glass particles are bound to each other and processed into a pellet or plate shape. These operations are repeated to produce at least three glass layers. And after measuring the thermal expansion coefficient of each obtained glass layer and laminating | stacking in order of a thermal expansion coefficient, it press-processes with the pressure of about 50 MPa-150 MPa, for example, and is integrated. Thereby, a bonding material (laminated glass) as disclosed herein can be obtained.

≪Join method≫
The bonding material (laminated glass) obtained as described above is different from the conventional bonding material in the laminating direction of the glass layer, from the glass layer (one glass layer surface) at one end to the other end. The coefficient of thermal expansion gradually increases (or decreases) toward the glass layer (the surface of the other glass layer). For this reason, it can use suitably for the joining of the member from which a thermal expansion coefficient differs greatly, for example, a ceramic member and a metal member.
In other words, the present invention provides a method for joining a ceramic member and a metal member. Such a bonding method includes the following steps: preparing a ceramic member and a metal member; applying the bonding material to a bonded portion between the ceramic member and the metal member; and preventing the applied bonding material from flowing out from the bonded portion. Firing in a temperature range.

  Specifically, first, a ceramic member and a metal member are prepared as members to be joined. Next, it arrange | positions so that these members may mutually contact and connect, and the bonding | jointing material disclosed here is arrange | positioned at the said connection site | part. And these composites are baked in the temperature range (typically 600 degreeC or more, for example, 700 to 900 degreeC) more than the softening point of a joining material (glass), and a glass component is hardened. Thereby, a joint part with high airtightness can be formed between to-be-joined members.

  The material to be joined (members to be joined) is not particularly limited. As a preferred example, a ceramic member made of a ceramic material such as alumina, mullite, steatite, forsterite, titania, yttria, chromia, zirconia, or partially stabilized zirconia is used. Can be considered. These may be a single element of any one ceramic material, or may be made of a ceramic composite material (for example, alumina zirconia, mullite, etc.) in which two or more of the ceramic materials exemplified above are combined. May be. Among these, fine ceramic materials such as alumina having various excellent properties mechanically, thermally, electrically, magnetically, and chemically can be preferably used. The thermal expansion coefficient of these ceramic members can be 6 ppm / K or more and 8 ppm / K or less as a rough guide.

  As another preferred example, a metal member made of a metal material such as stainless steel, aluminum, chromium, iron, nickel, copper, silver, manganese, and alloys thereof can be considered. More specifically, it may be ferritic or austenitic stainless steel, pure aluminum, aluminum alloy (duralumin, aluminum bronze, etc.), silver, silver alloy (Western silver, etc.), copper, copper alloy (phosphor bronze, etc.), etc. . In particular, the effect of the present invention is more exhibited when using a chromium-based material that easily reacts with an alkali component in a high-temperature environment or an inexpensive metal material that is not subjected to a film treatment (for example, stainless steel). obtain. The coefficient of thermal expansion of these metal members can be 10 ppm / K or more and 23 ppm / K or less (typically 10 ppm / K or more and 20 ppm / K or less, for example, 11 ppm / K or more and 17 ppm / K or less) as an approximate guide.

≪Joint body≫
In this way, it is possible to obtain a joined body including two or more members having different thermal expansion coefficients and a joint portion that joins the members. According to the bonding material disclosed herein, excellent heat resistance, chemical stability, and long-term durability can be imparted to the bonding portion between the members. Therefore, the joined body can be stably used over a long period of time in various environments (for example, in a high temperature environment or a strong acid or strong alkali atmosphere). In one preferred example, a joined body including a ceramic member and a metal member having different thermal expansion coefficients and a joint portion that joins the two members can be obtained.
Specifically, the joined body disclosed herein includes various power generation systems such as semiconductor devices, liquid crystal panels, power storage elements and solar cells, manufacturing devices for manufacturing them, waste incinerators, sewage treatment devices, and exhaust gas. It is an assembly of ceramic members and metal members used to construct environmental devices such as removal devices, exhaust gas treatment devices for vehicles, engine combustion test devices, vacuum supply / exhaust devices, medical devices, semiconductor devices, etc. obtain.

  Hereinafter, some test examples relating to the present invention will be described, but the present invention is not intended to be limited to those shown in the test examples.

  Here, a total of eight types of glass bonding materials (S1 to S8) were produced using the plate-like glasses a to j having the compositions shown in Table 1, and the bonding property was evaluated.

[Evaluation of thermal expansion coefficient]
The said plate-like glass aj was cut out to the column shape of about (PHI) 5mm x 10mm-20mm with the diamond cutter, respectively, and it was set as the test piece for a measurement. This test piece was evaluated using a thermomechanical analyzer (manufactured by Rigaku Corporation, TMA8310). Specifically, the average linear expansion amount between 30 ° C. and 500 ° C. when the temperature was raised from room temperature (25 ° C.) to 1000 ° C. at a constant rate of 10 ° C./min was calculated. The results are shown in Table 1.

[Jointability evaluation]
First, those selected from the plate glasses a to j were laminated in the order shown in Table 2, and integrated by press molding at about 50 MPa to 150 MPa, respectively, to obtain laminated glasses (S1 to S8). . Next, these laminated glasses were placed between the members to be joined (metal and ceramics) shown in Table 2, and were fired at 800 ° C. to 1100 ° C. for 1 hour in a nitrogen atmosphere, thereby attempting to join the members to be joined. .
In addition, the thermal expansion coefficient of the metal member and ceramic member which were used for the test is as follows.
-Ferritic stainless steel (SUS430) Thermal expansion coefficient: 11.5ppm / K
Ferritic stainless steel (SUS310) Thermal expansion coefficient: 16.5 ppm / K
・ Alumina Thermal expansion coefficient: 7.0 ppm / K

After that, it was confirmed whether each laminated body was bonded or whether airtight bonding was realized when bonded. Specifically, in order to consider the effect of residual stress, after being left in a room temperature environment for 3 days, the two parts are mechanically bonded depending on whether the bonded part can be peeled off from the material to be bonded using tweezers. It was confirmed whether or not. About the joined body which can confirm joining, a penetration flaw inspection was further performed and the presence or absence of the crack was confirmed.
The results are shown in the column of bondability in Table 3. In Table 3, “◎” indicates that both were mechanically bonded and no crack was observed, and “×” indicates that a bonding failure (peeling) or a crack was observed at the bonded portion. .

  Table 3 shows the difference in thermal expansion coefficient between adjacent glass layers simultaneously with the result of evaluation of bondability. As shown in Table 3, compared to S5 to S8, stainless steel and alumina were favorably bonded in S1 to S4. For this reason, laminated glass having a thermal expansion coefficient that differs stepwise between two adjacent glass layers and that has a difference in thermal expansion coefficient between the adjacent glass layers of 1.5 ppm / K or less is used as the glass bonding material. It was found that a highly airtight joint can be realized.

[Reactivity evaluation with stainless steel]
About the joined body (S1-S4) by which the favorable joining property between to-be-joined members was confirmed, it was confirmed whether reaction with the stainless steel used as a to-be-joined member had arisen. Stainless steel is mainly composed of iron (Fe) (50 mass% or more) and contains 10% or more of chromium (Cr) component. Therefore, here, stainless steel and glass are based on the diffusibility of Cr element. The reactivity of the bonding material was evaluated. Specifically, an observation image obtained by observing a cross section of the joined body with a scanning electron microscope (SEM) and using energy dispersive X-ray spectroscopy (EDX). By mapping Cr with the Cr element, it was confirmed whether Cr was diffused in the joint. In addition, as a comparative example, a separate joined body was prepared using a glass joining material containing potassium oxide, which is an alkaline component, in the joint portion, and similarly, it was confirmed whether Cr was not diffused in the joint portion. The results are shown in the column of reactivity with SUS in Table 3. In Table 3, “◎” represents that no Cr element was observed at the joint, and “x” represents that Cr element was observed at the joint.

  As shown in Table 3, in the comparative example, the diffusion of Cr element into the bonded portion was recognized, and the reaction between stainless steel as the member to be bonded and the glass bonding material occurred. On the other hand, in S1 to S4 not containing an alkali component, no diffusion of Cr element to the joint was observed, and no reaction with stainless steel was confirmed. This result shows the technical significance of the present invention.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

10 Bonding material (laminated glass)
10a First surface (surface on the ceramic member side)
10b Second surface (surface on the metal member side)
12 X layer (thermal expansion coefficient small glass layer)
14 Y layer (medium thermal expansion coefficient glass layer)
16 Z layer (Glass layer with large thermal expansion coefficient)

Claims (8)

A bonding material used for bonding between members having different thermal expansion coefficients,
It is composed of three or more glass layers, and in the laminating direction of the glass layers, a thermal expansion coefficient of 30 ° C. to 500 ° C. is stepwise from the glass layer at one end toward the glass layer at the other end. A laminated glass that increases to
The difference in thermal expansion coefficient between 30 ° C. and 500 ° C. between adjacent glass layers is 1.5 ppm / K or less,
A bonding material in which none of the glass layers contains an alkali component.   The three or more glass layers each independently include an oxide of one or more elements selected from the group consisting of Ba, Si, Al, Ti, Zn, B, and Ca. The bonding material according to 1.   The bonding | jointing material of Claim 1 or 2 whose thermal expansion coefficient in 30 to 500 degreeC of the said laminated glass is 5 ppm / K or more and 20 ppm / K or less. The entire laminated glass is a mass ratio in terms of oxide,
BaO 50-65 mass%,
SiO ₂ 20~35% by weight,
Al ₂ O ₃ 5 to 15 wt%,
TiO ₂ 1-10% by mass,
ZnO 0-5% by mass,
B ₂ O ₃ 1-5% by mass,
1 to 5% by mass of at least one of MgO, CaO and SrO,
The bonding | jointing material of any one of Claims 1-3 containing these components. The coefficient of thermal expansion at 30 ° C. to 500 ° C. of the glass layer at the one end is 6 ppm / K or more and 8 ppm / K or less,
The bonding | jointing material of any one of Claims 1-4 whose coefficient of thermal expansion in 30 to 500 degreeC of the glass layer of said other edge part is 10 ppm / K or more and 16 ppm / K or less. A ceramic member, a metal member, and a joining portion for joining the two members;
The said junction part is a joined body comprised with the joining material of any one of Claims 1-5. The ceramic member is made of a ceramic material having a thermal expansion coefficient of 30 to 500 ° C. of 6 ppm / K or more and 8 ppm / K or less,
The said metal member is a joined body of Claim 6 comprised with the metal material whose thermal expansion coefficient of 30 to 500 degreeC is 10 ppm / K or more and 23 ppm / K or less. The ceramic member is made of alumina ceramics,
The joined body according to claim 6 or 7, wherein the metal member is made of stainless steel.

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