JPH06305846A - Box-like member made of silicon nitride-based ceramic - Google Patents

Abstract

PURPOSE:To provide a sintered compact of silicon nitride-based ceramics being more lightweight than a metal material conventionally used, having high strength, high stiffness and low thermal expansion and excellent in abrasion resistance. CONSTITUTION:This box-like member is made of silicon-based ceramic sintered compact excellent in lightweight properties, high strength, high stiffness and low thermal expansion property as well as abrasion resistance and is obtained by joining a member 51 having a lid face and at least other two members with an adhesive. Further, a reinforcing rib is provided in the interior of the box-like member and the box-like member may have irregular shape on the surface or have holes in a part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded body of silicon nitride ceramics. More specifically, the present invention relates to a silicon nitride ceramic box-shaped member having high strength, high rigidity, and excellent wear resistance.

[0002]

2. Description of the Related Art Silicon nitride ceramics (including sialon) is a material suitable for applications that require high strength and high rigidity and wear resistance.

Therefore, if a hollow molded body can be formed from such a silicon nitride ceramics, it can replace various solid or hollow molded articles, containers, etc. which are conventionally manufactured from steel, cemented carbide and the like. Therefore, it is possible to further improve the characteristics such as weight, strength, rigidity and wear resistance.

Specifically, in a measuring device or the like that involves a plane movement such as a dimension measurement, a linear table or an XY stage capable of precise alignment is required.

In order to satisfy the requirements for extremely precise positioning, not only the position detection / control technology, but also the weight reduction, high rigidity and low thermal expansion of the constituent members are required, and the high elastic modulus and low heat of ceramics are required. Focusing on the expansion coefficient, proposals have been made to use this material.

For example, a hollow prismatic ceramic rod material pre-sintered / formed is stacked in a grid pattern between two ceramic plate materials pre-sintered, and each member is made of ceramics. It is a ceramic member that is heated to near the sintering temperature and solid-phase bonded (Actual Kaihei 2-900).
No. 78).

However, the preparation of hollow prismatic ceramics with uniform dimensional accuracy complicates the manufacturing process, and the solid-phase bonding method applied to the means for manufacturing a ceramics component generally requires a bonding pressure. Since the joining temperature is high and the joining temperature is high, the grain growth of the crystal grains of the ceramic member may be caused, and the deformation and strength of the joining member may be impaired.
There is a demand for a joining method that can easily obtain a joined body having high strength, high rigidity, and low thermal expansion.

[0008]

In view of the above problems, the present invention is a sintered compact of silicon nitride ceramics which is lightweight, has high strength, high rigidity, low thermal expansion and is excellent in wear resistance. It is intended to provide.

[0009]

The present invention is to solve the above-mentioned various problems, and is a box made of a silicon nitride-based ceramics sintered body excellent in lightweight, high strength, high rigidity, low thermal expansion and wear resistance. A box-shaped member made of silicon nitride ceramics, which is formed by joining a member on the lid surface and at least two other members with an adhesive.

Further, a reinforcing rib is provided inside the box-shaped member, and the lid member of the box-shaped member has an uneven shape or a partial hole on its surface. Good.

[0011]

The box-shaped member made of silicon nitride ceramics of the present invention is a box-shaped molded body having a hollow, and at least two members made of a silicon nitride ceramics sintered body have a specific adhesive as described later. Since the adhesive strength is extremely high at the joint, it does not impair the properties of silicon nitride ceramics such as high strength, high elastic modulus, and excellent wear resistance, and is lightweight and highly rigid. To form a molded body of.

In order to manufacture the silicon nitride ceramic box-shaped member of the present invention, a plate having a simple shape obtained by dividing each member constituting the box-shaped member with a reinforcing rib inside the lid into two or more parts. A molded body can be formed by using a bar or a rod.

The above-mentioned materials such as plates and rods having a simple shape have no difficulty in forming them, and thus they are produced by various known forming methods such as a uniaxial pressure forming method, a slip casting method and a CIP method. It is possible to

A base material having a desired shape is obtained by various molding methods as described above, and the base material is fired according to a conventional method. If necessary, further secondary processing can be performed before and after firing.

The silicon nitride ceramic constituting each of these members should have a composition containing silicon nitride (Si ₃ N ₄ ) as a main component, preferably 80% by weight, more preferably 90% by weight or more. There is no particular limitation, and a sialon composition which is particularly excellent in high rigidity, low thermal expansion and wear resistance for solving the above problems can also be preferably used from the above-mentioned compositions.

It should be noted that the shape of each constituent member may be any shape as long as it can be formed into a box shape having an internal space by combining them.

When the final product shape is a box having an internal space, for example, as shown in FIGS. 1 and 2, a box-shaped member 11 having an open upper end and a lid closing the upper end. It is possible to combine the two constituent members, such as the member 12 in the shape of a circle, into the final shape.

Depending on the final shape to be obtained, the lid-shaped member 12 may have a single plate shape as shown in FIG. 1 or a complicated shape as shown in FIG. It may be.

In particular, for a lid with a complicated shape having irregularities or holes on its surface, the present invention will be described with reference to a linear table or X
When it is applied to a Y stage, it is used as a planar moving part for positioning or the like, and is given a shape for the purpose of facilitating the combination with other parts through a hole provided on the lid surface.

On the other hand, even if the box-shaped member 11 is shaped as shown in FIG.
And one having only one recess as shown in FIG. 4, or one having a plurality of recesses defined by reinforcing ribs (partitions) 13 as shown in FIGS. 5 and 6. good.

According to the numerical calculation, the rigidity of the silicon nitride ceramic box-shaped member constituted by the reinforcing ribs is improved by about 10 times that of the conventional metal member, for example, the cast iron box-shaped member having the same shape.

Further, the silicon nitride ceramics used in the present invention have preferable physical properties such as a specific gravity of 1/2 to 1/3 that of cast iron and a thermal expansion coefficient of about 1/5.

Therefore, the physical properties of the ceramics used in the present invention and the features such as the structure of the box-shaped member having the lid and the reinforcing ribs are one of the factors for solving the problem.

The shape of the box-shaped member 11 having a plurality of recesses as shown in FIGS. 5 and 6 is a general molding such as the above-mentioned uniaxial pressure molding method, slip casting method, CIP method or the like. Since it is relatively difficult to manufacture by the method, the box-shaped member 11 having the plurality of recesses is further composed of a plurality of members. For example, each of the members forms the box-shaped member 11 with each reinforcing rib (partition) 13. It can have a shape that is divided in parts.

When joining these to the lid-shaped member 12,
You may form a box-shaped member by joining mutually simultaneously.

Further, in a box-shaped member having a large and complicated recess, as shown in, for example, FIGS. 7 and 8, a lower box-shaped member 31 having an open upper end and an open lower end formed by inverting the lower box-shaped member 31. In combination with the two upper and lower box-shaped members 32, or alternatively, as shown in FIGS. 9 and 10, for example, a hollow rectangular member 4 having an open right end is opened.
1, the hollow rectangular member 42 with both ends open, and the hollow rectangular member 43 with the left end opened can be combined into the final shape.

Further, in FIGS. 11 and 12, a lid portion 51 having an uneven surface and a sleeve strong rib (partition) 53 produced by any of the methods described in FIGS. 3 to 9 and 10 are provided. The lower box-shaped member 52 can be joined to form a component such as a linear table or an XY stage.

The lid 51, the lower box-shaped member 52 and the reinforcing rib 53 may be joined at the same time.

Next, in manufacturing the silicon nitride ceramics compact of the present invention, when the above-mentioned constituent members are joined together, the end faces of the joined portions of the constituent members are R _max.
It is desirable that the thickness is less than 10 μm, more preferably 8 μm or less, in order to improve the adhesiveness of the bonding surface and achieve good bonding.

Further, as the adhesive used for joining, it is desirable to use the adhesive disclosed in JP-A-2-192471.

Detailed adhesive components are Y ₂ O ₃ 13 to 56.
% By weight, more preferably 25-40% by weight, Al ₂ O ₃
4 to 42% by weight, more preferably 10 to 15% by weight, S
iO ₂ 0.7 to 28% by weight, more preferably 5 to 10% by weight, and the composition of Si ₃ N ₄ balance (hereinafter referred to as adhesive A).

Further, 36% by weight of Y ₂ O ₃ and Al ₂ O ₃ 1
A composition having a composition close to ₂ % by weight, 7% by weight of SiO ₂ and 45% by weight of Si ₃ N ₄ is most desirable.

In the adhesive A, the average particle size of Si ₃ N ₄ is 1.0 μm or less, more preferably 0.3 to 0.5 μm.
A value of m is desirable in order to obtain a stronger bonding strength.

The adhesive A is applied to the joint end surfaces of a plurality of constituent members used for joining, by mixing the adhesive A (powder) with an appropriate developing solvent to form a slurry, which is sprayed and dipped. Or by brushing.

The thickness of the adhesive on the joint surface of the adhesive A is preferably 20 μm or less, more preferably about 10 to 15 μm after the solvent is removed.

Then, after applying such an adhesive A to the joint end faces, the joint end faces of the respective constituent members are brought into contact with each other, and heat treatment is carried out while pressurizing so as to join them.

The applied pressure at this time is 10
-30 kgf / cm ² , more preferably 10-20 kg
A pressure of about f / cm ² may be applied.

Under this condition, good adhesion of the joint surface is maintained and the ceramic compact is not deformed.

The heat treatment conditions are 1500 to 1700 ° C. in a nitrogen atmosphere, more preferably 1550 to
1650 ° C., 10 to 60 minutes, more preferably 20 to 3
It is desired to heat and hold for about 0 minutes.

Under these conditions, crystal grain growth does not occur in the sintered ceramics-to-be-bonded, and the material strength does not decrease due to this.

Y ₂ O ₃ , Al ₂ O ₃ and S in adhesive A
During this heating, the io ₂ component melts and reacts with Si ₃ N _4, and during the heat treatment, the adhesive A changes into a composite ceramic of β-sialon crystals and a sialon glass phase, and the crystalline β- The abundance ratio of sialon to sialon glass is about 40:60 by volume.

During the heat treatment, a part of the melted component permeates / diffuses into the silicon nitride ceramics base material forming each of the above-mentioned constituent members, and a part thereof protrudes out of the joint surface under pressure. Therefore, if the coating thickness of the adhesive A on the joint surface is set to 20 μm or less as described above, the thickness will be 6 μm or less after the heat treatment.

As described above, when the adhesive A is used, the needle-like β-sialon crystals existing in the vitreous matrix after the heat treatment are bonded to each other and to the nitriding object to be bonded which constitutes the constituent member. Interlocking with the interface of the silicon-based ceramics base material to form a so-called interlocking state, and since the elements that constitute the amorphous component diffuse into the ceramics base material that constitutes each constituent member, The compositional change becomes gradual, and a strong bonding strength is obtained.

During the joining operation, if a connecting portion matching frame body (joining jig) fitted to the outer peripheral surfaces of the constituent members is arranged at the connecting portions of the constituent members, the joining end surfaces are displaced from each other. It is desirable because the alignment can be achieved without any damage and the desired final shape can be obtained with high accuracy.

As a material for forming the connecting portion matching frame body, it is sufficiently stable at a heating temperature at the time of bonding and has reactivity with the adhesive agent A to be used or a silicon nitride ceramics sintered body constituting each constituent member. There is no particular limitation, and the coefficient of thermal expansion thereof is substantially the same as that of the silicon nitride ceramics sintered body forming each component, but it is not particularly limited, but graphite is preferable.

Further, the alignment frame body of this connecting portion is required to have an inner frame dimension slightly larger than the outer frame dimension of the connecting portion of the component to be connected. The clearance between the outer surface and the inner surface of the connecting portion matching frame is 0.3 to 0.5 mm, more preferably 0.
It is about 1 to 0.2 mm.

The silicon nitride ceramics molded body of the present invention formed in this manner is extremely excellent in strength, rigidity, wear resistance and the like and is light in weight.
It is preferably used as a substitute for various solid or hollow molded articles and containers made of cemented carbide or the like.

In particular, FIGS. 1, 7 and 8 and FIG.
A box member having an internal space as shown in, for example, is a linear table or XY used in a precision measuring device or the like.
It is desirable as a structural member such as a stage, and among these, those having a structure in which the internal space is divided by the partition wall 13 as shown in FIGS. 8 and 10 have more strength and rigidity as a structural body. It is more desirable because it is expensive.

[0049]

EXAMPLES The present invention will be described in more detail below with reference to examples.

[0050]

Example 1 A hollow sialon box-shaped member having a 100 mm square and a height of 50 mm, a flat plate-like member (part number 12) having a wall thickness of 5 mm, and two partitioned internal spaces, and a side wall. And a box-shaped member (part number 11) with an opening at the upper end in which the thickness of the central partition wall is 7 mm, as shown in FIG.

Both of these members are uniaxially pressurized and further C
The base material was processed after IP molding.

The sialon ceramic used is one of silicon nitride ceramics having excellent wear resistance.

The adhesive applied to the joint between the lid member and the box-shaped member has a composition of 36% by weight of Y ₂ O ₃ and Al ₂ O _3.
It is composed of 12% by weight, 7% by weight of SiO ₂ and 45% by weight of Si ₃ N ₄ , and was applied by a spray coating method so that the adhesive thickness was about 15 μm.

Then, the joint end surfaces of both members were brought into contact with each other and held at 1600 ° C. for 15 minutes in a hot press heating furnace having a large hot zone capable of accommodating all of them.

It should be noted that a pressure of 10 kgf / cm ² was applied to the both members in the direction in which their joint end faces were pressed against each other until the temperature was heated from room temperature to 1600 ° C. and then cooled to room temperature again.

The box-shaped member thus obtained is bonded to the joint.
The joint strength is 4 for the joint part of the joint test piece, which was performed separately.
80kgf / mm2 from the result of point bending bending test Above
It is presumed that there is a lightweight, high-strength and highly rigid structure.
Was obtained.

[0057]

Example 2 Two hollow 100 mm cubic hollow sialon box-shaped members (part numbers 31 and 3) used in Example 1
2) was prepared by joining side surfaces on the opening side or ribs (part number 33) to each other as shown in FIG.

The adhesive composition used for joining, the temperature at the time of joining, the holding time, and the pressure were the same as in Example 1. As a result, the bonding strength at the bonding portion was 8 as in Example 1.
A high-strength and lightweight box, which is estimated to be 0 kgf / mm ² or more, was obtained.

[0059]

Example 3 Length 300 mm, Width 600 mm, Height 45
As shown in FIGS. 11 and 12, a sialon box-shaped member having an outer diameter of mm, a thickness of the thinnest portion of the wall surface of 4 mm, an upper surface lid portion having irregularities, and reinforcing ribs inside is formed. Lower box-shaped member with open upper end (part number 52)
And a reinforcing rib (part number 53) having a wall thickness of 4 mm and a height of 35 mm arranged in a grid pattern and a lid member (part number 51) having irregularities were joined.

Both of these members used in the manufacture of this box were uniaxially pressed and further subjected to CIP molding, processed into a predetermined shape, and immediately fired. Further, the lower box-shaped member and the rib surface that come into contact with the lid portion after firing were finished.

Adhesive composition used for joining, temperature at joining,
The holding time and the pressing force were the same as in Example 1, and the lid portion, the reinforcing rib, and the lower box-shaped member were simultaneously joined.

As a result, as in Example 1, the joint strength at the joint portion is estimated to be 80 kgf / mm ² or more, and the weight is about 1 / compared with the cast iron member having the same structure.
3. A silicon nitride-based ceramic member having a rigidity improved by about 8 times was obtained, and it was suitable for use as an XY stage of a precision measuring device.

[0063]

As described above, the silicon nitride ceramic molded body of the present invention is a box-shaped member having an internal space, and has various solid or hollow shapes conventionally made of steel, cemented carbide or the like. It is preferably used as an alternative to a molded product container, and when applied as a constituent member such as a linear table or an XY stage used in a precision side-by-side device, for example, high accuracy not obtained with conventional products can be obtained. Further, the life of the box-shaped member itself can be improved by, for example, the excellent wear resistance of silicon nitride ceramics and the strengthening of the joint.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the structure of one embodiment of a silicon nitride ceramics molded body of the present invention.

FIG. 2 is a vertical sectional view showing the structure of another embodiment of the silicon nitride ceramics molded body of the present invention.

3 is a cross-sectional view of a box-shaped member used in the embodiment shown in FIG.

FIG. 4 is a vertical sectional view of the box-shaped member.

FIG. 5 is a cross-sectional view showing another structural example of the box-shaped member.

FIG. 6 is a vertical sectional view of the box-shaped member.

FIG. 7 is a longitudinal sectional view showing the structure of another embodiment of the silicon nitride ceramics molded body of the present invention.

FIG. 8 is a longitudinal sectional view showing the structure of another embodiment of the silicon nitride ceramics molded body of the present invention.

FIG. 9 is a vertical cross-sectional view showing the structure of a silicon nitride ceramics compact according to another embodiment of the present invention before joining.

FIG. 10 is a vertical cross-sectional view showing the structure after joining of the embodiment.

FIG. 11 is a sketch drawing showing the structure of a lid portion having irregularities made of silicon nitride ceramics of the present invention.

FIG. 12 is a sketch drawing showing the lower box-shaped member of the embodiment and the reinforcing ribs arranged inside thereof.

[Explanation of symbols]

 11 Box-shaped member 12 Lid-shaped member 13 Reinforcing rib (partition wall) 31 Lower box-shaped member 32 Upper box-shaped member 41 Left hollow rectangular member 42 Central hollow rectangular member 43 Right hollow rectangular member 51 Lid part 52 Lower part Box-shaped member 53 Reinforcing rib

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidemi Nakayama 2-6-3 Otemachi, Chiyoda-ku, Tokyo Within Nippon Steel Corporation (72) Inventor Shuji Asada 2-6-3 Otemachi, Chiyoda-ku, Tokyo Within Nippon Steel Corporation

Claims (4)

[Claims] 1. A box-shaped member made of a silicon nitride-based ceramics sintered body, which is a box-shaped member made of a silicon nitride-based ceramics obtained by joining at least two members of a lid surface member and other members with an adhesive. . 2. A box-shaped member made of a silicon nitride-based ceramics sintered body, wherein the box-shaped member has a reinforcing rib inside, and at least two members of a lid surface member and other members are bonded together. Box-shaped member made of silicon nitride-based ceramics, which is bonded with a chemical. 3. The box-shaped member made of a silicon nitride ceramics according to claim 1, wherein the member of the lid surface has an uneven shape or a hole in a part thereof. 4. The box-shaped member made of a silicon nitride ceramics according to claim 1, which is used as a component of an XY stage.