JP2014047123A - Joining material and method of manufacturing joined body using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining material capable of minimize residual stress after joining regardless of an application temperature or kinds of a low expansion material to be joined.SOLUTION: A joining material contains a crystalline glass depositing 20 to 70 mass% of a LiO-AlO-SiO-based crystal and 1 to 75 mass% of a RO-AlO-SiO-based crystal (R=Mg, Ca, Sr, Ba) or a R'O-AlO-SiO-based crystal (R'=Na, K) by a heating treatment.

Description

  The present invention relates to a bonding material suitable for firmly bonding members to be bonded having a low linear thermal expansion coefficient.

  Quartz glass, low-expansion crystallized glass, low-expansion ceramics, and the like are excellent in heat resistance and thermal shock resistance, and are therefore widely used as jigs for high-temperature treatment, cookers, engines, and other members. In general, since these members are required to have a complicated shape, they are often difficult to produce by integral molding. In that case, the member of a desired shape is produced by joining each part of a member with a joining material.

  Conventionally, sealing glass and ceramic bonding materials have been mainly used as bonding materials for the above applications. However, generally, the linear thermal expansion coefficient of the sealing glass is higher than that of the member to be joined, and there is a problem that the bonding strength of the ceramic-based joining material is not sufficient. On the other hand, Patent Documents 1 and 2 disclose a bonding material (or sealing material) made of crystalline glass in which a low expansion crystal such as β-spodumene solid solution or β-quartz solid solution is precipitated as a main crystal. .

  The bonding material realizes low thermal expansion by offsetting the thermal expansion of each of the precipitated crystal (negative expansion) and the remaining glass phase (positive expansion), and the linear heat of the low expansion bonded member and the bonded portion. It is possible to match the expansion coefficients and to perform bonding with a small residual stress.

Patent Publication No. 2602187 Japanese Patent Publication No. 2715138

  When the bonding material is used, even if the average linear thermal expansion coefficient of the member to be bonded and the bonded portion are matched in a certain temperature range, the stress value generated between the two is due to the difference in the shape of the thermal expansion curve. It varies depending on the operating temperature range. Therefore, it is difficult to suppress the generation of stress during use. Also, when joining members with anisotropic thermal expansion (linear thermal expansion coefficients differ depending on the crystal axis direction), the residual stress varies depending on the crystal axis direction of the member to be joined. Uneven stress is likely to occur. For example, in a member for optical use, a slight residual stress may affect optical characteristics such as refractive index, which may cause problems in practice.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a bonding material that can extremely reduce the residual stress after bonding, regardless of the operating temperature and type of the low expansion bonded member. To do.

In the present invention, by heat treatment, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal 20 to 70 mass% and RO—Al ₂ O ₃ —SiO ₂ -based crystal (R = Mg, Ca, Sr, Ba) Alternatively, the present invention relates to a bonding material comprising crystalline glass in which 1 to 75% by mass of R ′ ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal (R ′ = Na, K) is precipitated.

The present inventor believes that crystals precipitated by heat treatment of crystalline glass are Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals, RO—Al ₂ O ₃ —SiO ₂ -based crystals, or R ′ ₂ O. It has been found that in the case of a mixed phase of —Al ₂ O ₃ —SiO ₂ -based crystals, it is possible to effectively suppress the occurrence of residual stress at the joint. The operation mechanism of the present invention is described below.

  Generally, the linear thermal expansion coefficient of crystallized glass is additively determined by the respective linear thermal expansion coefficients and contents of the precipitated crystals and the remaining glass phase. On the other hand, the bonding material of the present invention exhibits a linear thermal expansion coefficient lower than the linear thermal expansion coefficient predicted from the additive rule after the heat treatment. The reason is explained as follows.

Li ₂ O—Al ₂ O ₃ —SiO ₂ crystal, RO—Al ₂ O ₃ —SiO ₂ crystal, and R ′ ₂ O—Al ₂ O ₃ —SiO ₂ crystal are all anisotropic to thermal expansion. (The linear thermal expansion coefficient differs depending on the crystal axis). In crystalline glass in which these crystals are mixed and precipitated, a large thermal stress is generated between crystal grains depending on the combination of crystal axes in adjacent crystals, and accordingly, voids are generated in the glass after crystallization.

  The voids generated in the glass effectively act to reduce the residual stress at the joint after the heat treatment. That is, the gap has an action of absorbing the distortion generated at the interface between the member to be joined and the joined portion due to the difference in linear thermal expansion coefficient and suppressing the generation of thermal stress. In other words, the presence of voids exhibits plastic fluidity at the joint and has the effect of reducing elastic strain. Therefore, even when there is a difference in the coefficient of linear thermal expansion between the member to be joined and the joined portion, it is possible to suppress the occurrence of residual stress. Furthermore, even when the linear thermal expansion coefficient of the member to be joined has anisotropy, distortion generated in the direction of each crystal axis can be absorbed, so that uneven thermal stress is unlikely to occur at the joint.

  In addition, since the bonding material of the present invention can control the degree of void formation by changing the heat treatment conditions for crystallization, the thermal expansion coefficient of the bonded portion is independent of the material composition and the crystallinity. It is also possible to control. Therefore, the degree of freedom in material design of the bonding material is also increased.

  In the present invention, “crystalline glass” refers to glass having the property of precipitating desired crystals by heat treatment. “Heat treatment” refers to heat treatment at a temperature (at least above the softening point) at which desired crystals are precipitated from the crystalline glass.

The bonding material of the present invention, crystalline glass, in _{mass%, SiO 2 55~72%, Al} 2 O 3 14~30%, Li 2 O 1.5~10%, Na 2 O 0~10%, _{K 2 O 1~10%, 0~10%} MgO, CaO 0~10%, SrO 0~10%, BaO 0~10%, 0~5% ZnO, TiO 2 0~5%, ZrO 2 0~3 %, B ₂ O ₃ 0-3% and P ₂ O ₅ 0-1%.

  If it is the said structure, it will become easy to precipitate a desired crystal | crystallization by heat processing.

  In the bonding material of the present invention, the crystalline glass preferably precipitates β-spodumene solid solution and sanidine by heat treatment.

  If it is the said structure, the residual stress in the junction part after heat processing will become small easily.

The bonding material of the present invention preferably has an average linear thermal expansion coefficient at 30 to 530 ° C. of 15 × 10 ⁻⁷ / K or less after heat treatment.

  The bonding material of the present invention preferably has an average particle size of precipitated crystals of 0.5 μm or more.

  Moreover, this invention arrange | positions one of the said bonding | jointing materials between the 1st to-be-joined member and the 2nd to-be-joined member, and heat-processes, and thereby the 1st to-be-joined member and the 2nd to-be-joined The present invention relates to a method for manufacturing a joined body characterized by joining members.

  In the method for manufacturing a joined body according to the present invention, it is preferable that the first member to be joined and / or the second member to be joined is quartz glass.

  Furthermore, the present invention relates to a joined body manufactured by the above method.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the joining material which can make the residual stress after joining extremely small irrespective of the operating temperature and kind of a low expansion | swelling to-be-joined member.

In Example 1, it is a photograph which shows the joined body obtained by joining quartz glass using the joining material of this invention.

By the heat treatment, the bonding material of the present invention is Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal and RO—Al ₂ O ₃ —SiO ₂ based crystal (R = Mg, Ca, Sr, Ba) or R It is characterized by being made of crystalline glass on which ' ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals (R ′ = Na, K) are precipitated. The content (precipitation amount) of each crystal after the heat treatment is as follows.

The content of the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal is 20 to 70% by mass, and preferably 30 to 60% by mass. If the content of the Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal is too small, the linear thermal expansion coefficient of the joint portion increases, which may make it unsuitable for joining low-expansion joined members. On the other hand, if the content of Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal is too large, the heat treatment temperature tends to be high (for example, 1300 ° C. or higher), which may not be suitable for a normal heat treatment furnace.

Specific examples of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal include β-spodumene and β-spodumene solid solution.

The content (total amount) of RO—Al ₂ O ₃ —SiO ₂ crystal and R ′ ₂ O—Al ₂ O ₃ —SiO ₂ crystal is 1 to 75% by mass, preferably 5 to 60% by mass, More preferably, it is 10-50 mass%, More preferably, it is 20-45 mass%. If the content of RO—Al ₂ O ₃ —SiO ₂ -based crystal and R ′ ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal is too small, voids are not sufficiently generated at the joint, and the desired strain absorption effect And low thermal expansion properties are difficult to obtain. On the other hand, if the content of _{RO-Al 2} O 3 -SiO 2 based crystal and _{R '2 O-Al 2 O} 3 -SiO 2 based crystal is too large, the mechanical strength of the joint tends to decrease. In addition, these crystals may contain only 1 type and may contain 2 or more types.

Specific examples of the RO—Al ₂ O ₃ —SiO ₂ based crystal include the following. As MgO—Al ₂ O ₃ —SiO ₂ crystal, cordierite, etc .; CaO—Al ₂ O ₃ —SiO ₂ crystal, pyroxene, Ca feldspar, etc .; SrO—Al ₂ O ₃ —SiO ₂ crystal, Slowsonite and the like; BaO—Al ₂ O ₃ —SiO ₂ -based crystals include heavy feldspar.

Specific examples of the R ′ ₂ O—Al ₂ O ₃ —SiO ₂ based crystal include the following. Examples of Na ₂ O—Al ₂ O ₃ —SiO ₂ based crystals include feldspar and nepheline; and examples of K ₂ O—Al ₂ O ₃ —SiO ₂ based crystals include potassium feldspar such as orthofeldspar, sanidine and microclinic It is done.

Each crystal was listed as specific examples of the above _{RO-Al 2} O 3 -SiO 2 based crystal and _{R '2 O-Al 2 O} 3 -SiO 2 system crystal, it may be a solid solution.

  The bonding material of the present invention is preferably made of a crystalline glass that precipitates β-spodumene solid solution and sanidine by heat treatment. Thereby, it becomes possible to obtain a bonding material having a small residual stress in the bonded portion after the heat treatment.

The total amount of Li ₂ O—Al ₂ O ₃ —SiO ₂ crystal, RO—Al ₂ O ₃ —SiO ₂ crystal and R ′ ₂ O—Al ₂ O ₃ —SiO ₂ crystal is 40% by mass or more. It is preferably 50% by mass or more. If the total amount of these crystals is too small, the generation of voids at the joint tends to be insufficient. The upper limit is not particularly limited, but it is preferably 99% by mass or less, and more preferably 95% by mass or less in order to obtain good bondability.

  The average grain size of each crystal is preferably 0.5 μm or more, and more preferably 1 μm or more. If the average grain size of the crystal is too small, the expression of thermal stress due to the anisotropy of the linear thermal expansion coefficient of the crystal grain becomes small, and it becomes difficult to form sufficient voids at the joint. The upper limit is not particularly limited, but if the average particle size of these crystals is too large, the size of the generated voids tends to be too large, and the mechanical strength of the joint tends to decrease. Therefore, the average particle size of each crystal is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 100 μm or less.

The average grain size of the crystal is calculated based on a reflected electron image obtained by observing the crystallized glass surface with a scanning electron microscope. Specifically, the average crystal grain size is calculated as follows. First, the reflected electron image is binarized using an image processing system, and the area of each crystal particle is measured. Next, from the area, the diameter (d _ni ) of the crystal particle converted into a perfect circle is calculated by the formula d _ni = √ (4 / π · A). In addition, A is the area of the crystal grain calculated by image analysis of the reflected electron image. Subsequently, the average particle diameter (d _n ) of the crystals with respect to the number of particles _n is calculated according to the formula d _n = Σd _ni / n.

As the composition of the crystalline glass constituting the bonding material of the present invention, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal and RO—Al ₂ O ₃ —SiO ₂ -based crystal or R ′ ₂ O—Al There is no particular limitation as long as a predetermined amount of ₂ O ₃ —SiO ₂ -based crystals can be precipitated. For example, as a glass composition, in _{mass%, SiO 2 55~72%, Al} 2 O 3 14~30%, Li 2 O 1.5~10%, Na 2 O 0~10%, K 2 O 1~10 %, 0~10% MgO, CaO 0~10 %, SrO 0~10%, BaO 0~10%, 0~5% ZnO, TiO 2 0~5%, ZrO 2 0~3%, B 2 O 3 0-3% and those containing _P 2 _O 5 _0~1% is preferred.

  The reason for limiting the content of each component as described above will be described below. In the following description regarding the content of each component, “%” means “mass%” unless otherwise specified.

SiO ₂ is a main constituent of glass and a crystal constituent. The content of SiO ₂ is preferably 55 to 72%, more preferably 60 to 70%. When the content of SiO ₂ is too small, crystal precipitation tends to be unstable. On the other hand, if the content of SiO ₂ is too large, the softening point becomes high to decrease the softening fluidity of the crystalline glass, bonding property as a result tends to decrease. Moreover, there exists a tendency for meltability to fall and for preparation of homogeneous glass to become difficult.

Al ₂ O _{3 is} also a crystal constituent. The content of Al ₂ O ₃ is preferably 14 to 30%, more preferably 16 to 25%. When the content of Al ₂ O ₃ is too small, the precipitated crystal is coarsened and the mechanical strength of the joint tends to be lowered. On the other hand, when the content of Al ₂ O ₃ is too large, with the meltability decreases, it tends to be devitrified during molding liquidus temperature becomes high.

Li ₂ O is also a crystal constituent. The content of Li ₂ O is preferably 1.5 to 10%, more preferably 3 to 7%. When the Li 2 _O content is too small, there is a tendency for foreign crystals precipitate a desired crystal becomes difficult to obtain. On the other hand, when the content of Li 2 _O is too large, the softening fluidity is lowered crystallinity becomes strong, the bonding property as a result tends to decrease.

Na ₂ O is a constituent component of the Na ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which affects the softening fluidity. The content of Na ₂ O is preferably 0 to 10%, more preferably 0 to 7%. When the content of Na ₂ O is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, desired voids and linear thermal expansion coefficient is difficult to obtain.

K ₂ O is a component constituting a K ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which affects the softening fluidity. The content of K ₂ O is preferably 1 to 10%, more preferably 3 to 7%, and still more preferably 3.5 to 7%. When K ₂ O content is too _{small, K 2 O-Al 2 O} 3 -SiO 2 based crystal is less likely to precipitate. On the other hand, when the content of _{K 2} O is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, desired voids and linear thermal expansion coefficient is difficult to obtain.

The total amount of K ₂ O and Na ₂ O is preferably 1 to 20%, more preferably 3 to 10% in view of the above effects.

MgO is a constituent component of the MgO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which affects the softening fluidity. The content of MgO is preferably 0 to 10%, more preferably 0.1 to 9%, further preferably 1 to 8%, and particularly preferably 2 to 7%. When the content of MgO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, desired voids and linear thermal expansion coefficient is difficult to obtain.

CaO is a constituent component of the CaO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which affects the softening fluidity. The content of CaO is preferably 0 to 10%, more preferably 0 to 7%. When the content of CaO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, desired voids and linear thermal expansion coefficient is difficult to obtain.

SrO is a constituent component of the SrO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which affects the softening fluidity. The content of SrO is preferably 0 to 10%, more preferably 0 to 7%. When the content of SrO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, desired voids and linear thermal expansion coefficient is difficult to obtain.

BaO is a constituent component of a BaO—Al ₂ O ₃ —SiO ₂ based crystal. It is also a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. Furthermore, the softening point is adjusted by adjusting the proportion of the glass phase, which affects the softening fluidity. The content of BaO is preferably 0 to 10%, more preferably 0.1 to 9%, still more preferably 1 to 8%, and particularly preferably 2 to 7%. When the content of BaO is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, desired voids and linear thermal expansion coefficient is difficult to obtain.

The total amount of MgO, CaO, SrO and BaO is preferably 1 to 20%, more preferably 3 to 10% in view of the above effects.
In order to facilitate precipitation of desired crystals, the total amount of R ′ ₂ O (R ′ = Na, K) and RO (R = Mg, Ca, Sr, Ba) is preferably 1 to 20%. More preferably, it is 3 to 10%.

ZnO is a component that facilitates melting and a constituent component of garnite crystals. Since the garnite crystal has a relatively high refractive index, it is easy to obtain a bonded portion with high whiteness by positively containing ZnO. However, if the content of ZnO is too large, the precipitation of garnite crystals increases, and Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystals, RO—Al ₂ O ₃ —SiO ₂ based crystals and R ′ ₂ O precipitation amount -Al ₂ O ₃ -SiO ₂ based crystal tends to decrease. In view of the above, the content of ZnO is preferably 0 to 5%, more preferably 0 to 4%.

TiO ₂ and ZrO ₂ are components that become the nucleus of the precipitated crystal, and have an action of suppressing the coarsening of the crystal and an action of stably depositing the crystal. However, when the content is too large, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystals are preferentially precipitated, and RO—Al ₂ O ₃ —SiO ₂ -based crystals and R ′ ₂ O -Al ₂ O ₃ -SiO ₂ based crystal is less likely to precipitate. In addition, the crystallization speed increases and the glass tends to devitrify, and the softening fluidity tends to decrease.

Since TiO ₂ has a strong effect of accelerating the crystallization speed, if its content is too large, voids are excessively generated during the cooling process in the crystallization step, and the mechanical strength tends to decrease. On the other hand, ZrO ₂ has a smaller effect of promoting the crystallization rate than TiO ₂ , and if its content is too large, the growth of crystal grains in the crystallization process becomes insufficient, and the generation of voids is rather reduced. In view of the above, it is preferable to appropriately adjust the contents of TiO ₂ and ZrO ₂ . Specifically, the content of TiO ₂ is preferably 0 to 5%, more preferably 0 to 3%, and still more preferably 0.1 to 2%. The content of ZrO ₂ is preferably 0 to 3%, more preferably 0 to 2%, further preferably 0 to 1.4%, and particularly preferably 0.1 to 1%. The total amount of TiO ₂ and ZrO ₂ is preferably 0 to 5%, more preferably 0 to 3%, still more preferably 0 to 2%, particularly preferably 0 to 1.4%, and most preferably 0. 1-1%.

B ₂ O ₃ is a component for controlling the crystallinity of the Li ₂ O—Al ₂ O ₃ —SiO ₂ based crystal. In addition, the softening point is adjusted by adjusting the proportion of the glass phase, which affects the softening fluidity. The content of B ₂ O ₃ is preferably 0 to 3%, more preferably 0 to 2%. If the B ₂ O ₃ content is too _large, the less amount of precipitation of _{Li 2 O-Al 2 O 3} -SiO 2 based crystal, desired voids and linear thermal expansion coefficient is difficult to obtain.

P ₂ O ₅ is a component having an action of suppressing the coarsening of crystals. However, when there is too much the content, there exists a tendency for devitrification to become strong. Therefore, the content of P ₂ O ₅ is preferably 0 to 1%, more preferably 0 to 0.8%.

Also, depending on the color of the joint of interest, as a coloring component in the glass composition, may CoO, NiO, be contained _Fe 2 _{O 3} or _V 2 _{O 5.} The content of CoO + NiO + Fe ₂ O ₃ + V ₂ O ₅ is preferably 0.01 to 5%, more preferably 0.05 to 3%, and still more preferably 0.1 to 1%. When the content of CoO + NiO + Fe ₂ O ₃ + V ₂ O ₅ is too small, it is difficult to obtain a coloring effect. On the other hand, if the content of CoO + NiO + Fe ₂ O ₃ + V ₂ O ₅ is too large, the content of other components is relatively reduced, for example, the linear thermal expansion coefficient becomes too high due to a decrease in the amount of precipitated crystals, etc. May affect physical properties.

In the bonding material of the present invention, the absolute value of the average linear thermal expansion coefficient at 30 to 530 ° C. after heat treatment is preferably 15 × 10 ⁻⁷ / K or less, more preferably 10 × 10 ⁻⁷ / K or less. .

  The bonding material of the present invention may be composed of either bulk crystalline glass or powdered crystalline glass. When using powdery crystalline glass, the particle size is preferably 1 to 300 μm or less, and more preferably 10 to 200 μm or less, from the viewpoint of workability. The crystalline glass powder softens during the heat treatment and the particles are fused to each other, so that the size of the precipitated crystal may exceed the size of the initial glass powder particle.

  Next, an example of a method for manufacturing the bonding material of the present invention and a method for manufacturing a bonded body using the bonding material of the present invention will be described.

  First, the raw material powder prepared so as to have a desired composition is melted until it is uniform, and the molten glass is formed into a desired shape and slowly cooled to obtain a crystalline glass. Next, the crystalline glass is processed into a suitable form as a bonding material by a method such as grinding, polishing, and pulverization. For example, when obtaining a powdery crystalline glass, the glass after molding is pulverized by a pulverizer such as a ball mill and adjusted to a predetermined particle size.

When a bonding material made of powdered crystalline glass is used, water or an organic liquid and, if necessary, a binder or the like are added to the crystalline glass powder to form a slurry or paste. It arrange | positions by apply | coating or filling a bonding material to the desired site | part of a 1st to-be-joined member, and also makes a 2nd to-be-joined member contact a joining material. Here, when it is not preferable to use moisture or organic matter, the bonding material may be filled by a dry method. Next, the entire laminate of the first and second members to be bonded and the bonding material is heat-treated at a temperature equal to or higher than the softening point of the crystalline glass to cause the bonding material to flow and crystallize. The heat treatment temperature is equal to or higher than the softening point of the crystalline glass, and it is particularly preferable that the viscosity is in a temperature range where the viscosity is 10 ^4.5 to 10 ^5.5 poise (10 ^4.5 to 10 ^5.5 dPa · s). . Specifically, although it depends on the glass composition, the heat treatment temperature is preferably 950 ° C. or higher, more preferably 1030 ° C. or higher, and further preferably 1040 ° C. or higher. When the heat treatment temperature is too low, it is difficult to precipitate a desired type of crystal. On the other hand, if the heat treatment temperature is too high, the precipitated crystals are likely to melt, and the desired crystals are difficult to precipitate during the cooling process. As a result, it becomes difficult to obtain a desired air gap and linear thermal expansion coefficient. In addition, the burden on the heat treatment furnace increases, and the fuel cost tends to rise. In view of the above, the firing temperature is preferably 1300 ° C. or lower.

After being held at the heat treatment temperature for a predetermined time and then cooled, a joined body joined with the joining material of the present invention is obtained. In the present invention, the linear thermal expansion coefficient after heat treatment of the bonding material is greatly influenced by the cooling rate particularly in the cooling process. Therefore, by changing the cooling rate, it is possible to control the degree of void formation in the crystal phase or glass phase without changing the crystallinity, and to obtain the desired strain absorption effect and linear thermal expansion coefficient. Become. In the bonding material of the present invention, the degree of void generation can be increased by reducing the cooling rate in the cooling process. Specifically, the cooling rate is preferably 300 ° C./hour or less, more preferably 200 ° C./hour or less, and further preferably 100 ° C./hour or less. As a result, a predetermined amount of Li ₂ O—Al ₂ O ₃ —SiO ₂ crystal and RO—Al ₂ O ₃ —SiO ₂ crystal or R ′ ₂ O—Al ₂ O ₃ —SiO ₂ crystal were precipitated. Thus, an internal structure having a desired void and a linear thermal expansion coefficient can be easily obtained, and the residual stress at the joint can be extremely reduced.

  The heat treatment furnace is not particularly limited, and for example, a continuous furnace such as a roller hearth kiln or a tunnel kiln, or a batch furnace such as a shuttle kiln or a box furnace can be used. In addition to electricity, gas, and oil, microwaves can be used as the heating source.

  The method for heat-treating the entire laminate of the member to be bonded and the bonding material has been described above, but only the bonding material may be locally heated using a laser or the like.

Although it does not specifically limit as a material of a 1st to-be-joined member and a 2nd to-be-joined member, If the joining material of this invention is used, quartz glass (Linear thermal expansion coefficient: 5.5 * 10 < ^-7 > / K) In addition, a material having a low linear thermal expansion coefficient, such as low expansion crystallized glass and low expansion ceramics, can be bonded with a small residual stress.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples.

(Examples 1-3)
(A) Production of crystalline glass After melting glass raw materials prepared so as to have the respective glass compositions shown in Table 1 at a predetermined temperature in an electric furnace for 12 hours, the molten glass is poured into twin rollers and rapidly cooled. And formed into a 0.5 mm thick plate. Next, the plate glass was pulverized using a ball mill, and a crystalline glass powder (bonding material) having an average particle size of 150 μm was obtained using a sieve.

(B) Manufacture of joined body After adding ion-exchanged water to crystalline glass powder to form a slurry, the slurry is applied to a rectangular surface of quartz glass having dimensions of 50 mm × 5 mm × 5 mm, and the same size is applied thereon. Quartz glass was stacked in the same direction and dried at 80 ° C. for 1 hour. Then, the quartz glass joined body joined by the joining material was obtained by heat-processing in the temperature of Table 1 in an electric furnace. The residual stress in the vicinity of the joint of the obtained joined body was measured by the Senarmon method. The measurement results are shown in Table 1. In addition, FIG. 1 shows a polarizing microscope photograph near the joint.

  The heat treatment conditions in the joining process were as follows. First, after raising the temperature from room temperature to 500 ° C. at a rate of 500 ° C./h, the temperature was further raised to a predetermined firing temperature shown in Table 1 at a rate of 100 ° C./h, and then kept for 1 hour. Then, after cooling to 500 ° C. at a rate of 100 ° C./h, it was further cooled to room temperature at a rate of 300 ° C./h.

(C) Measurement of physical properties of bonding material The crystalline glass powder obtained in (a) is pneumatically press-molded with a pressing device so as to be a prismatic column of 80 mm × 5 mm × 5 mm, and is subjected to heat treatment under the same conditions as above. Crystallized glass was obtained. Part of the obtained crystallized glass was used to identify the precipitated crystals and measure the amount of crystals with an X-ray diffractometer (RINT2100 manufactured by Rigaku Corporation). The amount of crystals was measured by a multiple peak separation method. The measurement results are shown in Table 1.

  Furthermore, the linear thermal expansion coefficient in 30-530 degreeC was measured using the remaining sample using the dilatometer (TD5010 by Bruker AXS). The measurement results are shown in Table 1.

Example 4
(A) Production of crystalline glass A glass raw material prepared so as to have the same composition as in Example 3 was melted in an electric furnace at a predetermined temperature for 12 hours. The molten glass was cast out into a carbon plate shape, molded, annealed, and then polished into a plate shape having a thickness of 50 mm × 5 mm × 1 mm to obtain a crystalline glass plate (joining material).

(B) Manufacture of joined body A crystalline glass plate on a rectangular surface of quartz glass having a size of 50 mm × 5 mm × 5 mm, and a quartz glass having the same size as that of the quartz glass are stacked in the same direction on the rectangular surface. By performing heat treatment at the temperature shown in Table 1, a quartz glass joined body joined with a joining material was obtained. The residual stress in the vicinity of the joint of the obtained joined body was measured by the Senarmon method.

(C) Measurement of physical properties of bonding material Crystallized glass processed into a prismatic shape of 80 mm × 5 mm × 5 mm was subjected to heat treatment under the same conditions as above to obtain crystallized glass. Using the resulting crystallized glass, identification of precipitated crystals and measurement of the amount of crystals were carried out in the same manner as in Examples 1 to 3, and the linear thermal expansion coefficient at 30 to 530 ° C. was measured.

(Comparative Examples 1 and 2)
A crystalline glass powder was prepared in the same manner as in Examples 1 to 3 except that a glass raw material prepared so as to have the glass composition shown in Table 1 was used, and each physical property was measured. The results are shown in Table 1.

  As is clear from Table 1, in Examples 1 to 4, the residual stress value at the joint is as small as 3 MPa or less. Moreover, the photograph of FIG. 1 shows that the light transmission state in the quartz glass near the joint is uniform and the residual stress value is extremely small.

On the other hand, although the crystallized glass bonding materials of Comparative Examples 1 and 2 had a relatively low linear thermal expansion coefficient of 10 × 10 ⁻⁷ / K or less, the residual stress value increased to 15 MPa or more.

1 Quartz glass 2 Joint

Claims (8)

By heat treatment, Li ₂ O—Al ₂ O ₃ —SiO ₂ -based crystal 20 to 70 mass%, and RO—Al ₂ O ₃ —SiO ₂ -based crystal (R = Mg, Ca, Sr, Ba) or R ′ _{2 O-Al 2} O 3 -SiO ₂ based crystal (R '= Na, K) 1~75 wt% bonding material, characterized in that it consists of crystalline glass to deposit. Crystalline glass, in _{mass%, SiO 2 55~72%, Al} 2 O 3 14~30%, Li 2 O 1.5~10%, Na 2 O 0~10%, K 2 O 1~10% , 0~10% MgO, CaO 0~10% , SrO 0~10%, BaO 0~10%, 0~5% ZnO, TiO 2 0~5%, ZrO 2 0~3%, B 2 O 3 0 bonding material according to claim 1, characterized in that it contains 3% and _P 2 _O 5 _0~1%.   The bonding material according to claim 1 or 2, wherein the crystalline glass precipitates β-spodumene solid solution and sanidine crystals by heat treatment. 4. The bonding material according to claim 1, wherein an absolute value of an average linear thermal expansion coefficient at 30 to 530 ° C. is 15 × 10 ⁻⁷ / K or less after the heat treatment.   The bonding material according to any one of claims 1 to 4, wherein an average particle size of the precipitated crystals is 0.5 µm or more.   By arranging the bonding material according to any one of claims 1 to 5 between the first bonded member and the second bonded member and performing a heat treatment, the first bonded member and the second bonded member. A method for manufacturing a joined body comprising joining members to be joined.   The method for manufacturing a joined body according to claim 6, wherein the first member to be joined and / or the second member to be joined is quartz glass.   A joined body produced by the method according to claim 6 or 7.