JPH02263772A - Joint plate of ceramic and method for joining this joint plate to metallic plate - Google Patents

Abstract

PURPOSE:To enhance joint strength by continuously arranging ceramics chips, connecting and fixing the mutually connected parts with joint metal and then fixing this fixed ceramics joint plate to a metallic plate by a bolt. CONSTITUTION:A ceramics joint plate 3 is formed by zigzag arranging the ceramics chips 1 such as SiC made of a square of 20 to 30mm and applying an Ag-Cu-Ti-based active metallic paste-brazing material to the contact parts X of the respective ceramics chips 1 and arranging the ringlike joint metallic pieces 2 such as Cu, Ni, W and Mo, heating and joining them. Bolts 4 are uniformly dispersed and provided at the prescribed intervals to the installation parts of the joint metal of this joint plate 3. The intervals between the bolts 4 and the joint metal 2 are buried by the brazing material and both are heated and joined. The bolts 4 are perforated through the metallic plate and fixed by mechanical joint for clamping them by nuts. Further brazing material is applied to one part or the whole part of many joint metals 2. The applied faces are allowed to coincide with the metallic plate. This metallic plate can be tightly joined to the ceramics joint plate 3 by locally heating it with high frequency induction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a large-area ceramic bonding plate by bonding small-area ceramic chips (chips) and a ceramic bonding method for bonding the same to a metal plate.

(Prior Art) Ceramics have excellent heat resistance and wear resistance, and various products that actively utilize these properties have been put into practical use. However, although ceramics have these characteristics, they lack toughness and are brittle, making them unreliable as structural materials and are rarely used alone.

That is, it is usually used in combination with a metal material having high toughness.

Various methods have been developed to combine ceramics and metal materials. For example, JP-A-60-166
Methods using Ag-Cu brazing filler metal containing active metals as disclosed in Japanese Patent Laid-open No. 165 and No. 62-217533, and methods for improving bonding strength as in Japanese Patent Application Laid-open No. 139088-1988. A method has been proposed in which metallizing metal (T1.Zr) powder is applied to the ceramic surface, a plate-shaped brazing material is placed, and the metal feed is bonded to the ceramic surface.

When bonding these ceramic-metal materials, a metallizing metal and a brazing filler metal are applied to the entire surface of the ceramic and then heated to join the ceramic to the metal. Ceramics and metal materials each have different coefficients of thermal expansion; for example, alumina has a coefficient of 8 x 10'/'C, whereas iron has a coefficient of 12 x 10'/'C, and copper has a coefficient of expansion of 17 to 18 /°C. Therefore, stress is generated in the ceramic due to thermal deformation of the metal material during bonding, and this may cause cracks in the ceramic. The residual stress generated in the ceramic increases as the bonding surface with the metal material increases. Therefore, in order to disperse the stress that occurs, it is necessary to use small pieces of ceramic.

Another method for reducing the residual stress is a method of attaching (brazing) a smaller circular stress-buffering copper plate to ceramics and joining this to a metal material with a brazing material, as disclosed in Japanese Patent Application Laid-Open No. 131-198. It is disclosed in Japanese Patent No. 117170.

(Problems to be Solved by the Invention) As described above, in a composite material of a metal material that is metallized or brazed on the entire surface of a ceramic, stress remains inside the ceramic. Therefore, in order to reduce the generation of residual stress, there is a restriction that a ceramic piece of small area must be used.

In addition, even for large-area ceramic pieces, a method is used to reduce the bonding area by distributing and bonding small (small pieces) stress buffering materials, but large-area ceramics are expensive to manufacture and are brittle materials, making them difficult to handle and work with. There are some difficulties.

The present invention solves the above-mentioned 1. problems when conventional ceramics and metal materials are composited. sized ones are easy to work with,
That is, it is an object of the present invention to provide a method for easily obtaining a relatively large-area ceramic bonding plate and for easily bonding this bonding plate to a metal material.

(Means for Solving the Problems) The present invention provides a large IFI in which ceramic chips are arranged in succession and the parts where these ceramics come in contact with each other are connected and fixed by a bonding metal that spans each adjacent ceramic chip. The first invention is a ceramic bonded plate of the same type.

On the surface of the ceramic bonding plate on which the bonding metal is installed,
A second invention is that bolts are planted at predetermined intervals,
The third invention is a method of fixing and joining a ceramic bonding plate and a metal plate (metal material) using the implanted bolts.

In order to bond a metal plate to the bonding plate of the first invention, when stacking the metal plate through the bonding metal, a brazing material is attached between a predetermined number or all of the bonding metals and the metal plate, and the ceramic High-frequency local heating is applied to one or all of the many joint metal parts from the chip side. This is the fourth invention.

The present invention will be explained in detail below.

The ceramics used in the present invention can be almost any conventionally used ceramics.

That is, oxide-based, nitride-based, or other types of materials may be used, but materials with too large an area should be avoided. In other words, manufacturing cost and manufacturing 1J? J: There are problems with accuracy, etc., and also when repairing the actual machine. Also, if the pieces are too small, the work efficiency will be poor and the cost will increase. Therefore 20-3
01 square chips are preferred.

However, this size is not a limitation of the invention. Further, the shape of the ceramic chip is not limited to a square, but may be any other polygon.

A description will be given below based on an example of a rectangle.

The ceramic chips are arranged in a staggered manner, and a bonding metal is bonded to the contact portions. As shown in one embodiment in FIG. 1, the ceramic snaps 1 are arranged in a staggered manner in a plurality of rows. In other words, the corners of the ceramic chip a and the adjacent ceramic snap b in one row contact the side of the ceramic step C in the next row at point X, and the corners of the adjacent ceramic chips C and d contact the side of the ceramic step b in the previous row. and is in contact at point Y. In the present invention, the contact portion of the ceramic chip is this point X, Y
Points (including their neighbors).

In the example shown in the figure, a joining metal piece 2 is placed at each of the contact parts X described above, and the ceramic steps a and b are bonded by heating.
, c are fixed to form a ceramic bonded plate. Joint part Y
Of course, it is also possible to join with the joining metal piece 2 for X.

Whether to select the entire Y point or any portion may be determined based on the size of the ceramic chip, the required bonding strength, etc.

When the shape of the joining metal is square or polygonal, stress concentration occurs at some corners during joining. Therefore, a circular shape is best because the stress is uniform in all directions, and a ring shape as shown in the figure is especially convenient because it allows the brazing material to be supplied to the center and has the function of storing the brazing material and retaining the brazing material. . The size of the bonding metal is approximately 1/3 to 1/2 of the length of the ceramic chip, and these should be made of soft metals such as copper and nickel, or metals with thermal expansion coefficients similar to those of ceramics such as tungsten and molybdenum. To be elected.

In order to bond ceramic chips to form a large-area bonded plate, the ceramic chips are arranged in a staggered arrangement to an appropriate size to form a ceramic aggregate.
Apply metallizing paste (for example, Ag-Cu-TI brazing filler metal) to the contact area
iL, and a circular bonding metal (for example, Cu) is placed thereon. In this case, it is preferable to apply the metallizing paste only to the area where the bonding metal is to be placed. Heating the ceramic assembly with this bonded metal placed on it (in vacuum or in an inert atmosphere)
Thus, metallization and bonding can be performed simultaneously to manufacture the ceramic bonded plate 3.

In the present invention, the area of the bonding surface between the ceramic chip and the bonding metal is extremely small, so even if there is a difference in the coefficient of thermal expansion between the two, the generation of stress is small and hardly a problem. In this state, the ceramic chips are firmly bonded to each other.

In FIG. 2, bolts 4 are implanted at specific intervals on the metal joining surface of the ceramic joining plate 3 shown in FIG. Since these bolts are for mechanically joining the ceramic bonding plate to the metal plate, at least two bolts may be provided per ceramic bonding plate so that the bonding plate can be fixed on a flat surface. Therefore, the spacing is not particularly specified, and the bolts may be planted so as to be evenly distributed on the joint plate surface. In addition, if further bonding strength is required depending on the usage environment, the bolts may be planted more densely and evenly.

The bolts 4 can be installed by interposing a brazing material between the joining metal and the bolt, heating and brazing, and 1. At the same time as the above-mentioned metallization, a joining metal to which bolts have been joined in advance may be joined to the contact portion of the ceramic chip.

The ceramic bonded plate is bonded to metal to form a composite. In this case, a brazing filler metal is applied in paste form to the surface of the bonded metal, the coated surface is aligned with the metal plate, and a high-frequency induction coil is placed on the ceramic chip surface. The joints of each chip are locally heated in sequence by bringing them close to each other. As a result, the joining metal is melted, and the joining plate and the metal plate are firmly joined at the locally heated portion.

It is not necessarily necessary to apply the brazing filler metal to all the bonded metals, and it may be selected as appropriate, such as every other metal. There is also a brazing method in which the filler metal is supplied from the chip gap (joint) to the center (core) of the ring-shaped joining metal. Then, local heating is sequentially applied to this part using high frequency. In short, it is sufficient if it can be firmly bonded to the metal plate. In addition, when the paste is supplied in the form of a ring, the working efficiency can be improved by filling the core portion of the bonding metal.

In the bolted joint plate of the present invention, the bolts can be passed through the metal plate and fixed by mechanical joining using well-known nuts or the like. In this example, there is no need to attach a brazing filler metal.

Also, bolts that protrude above the metal plate can be cut off.

The case where square ceramic chips are arranged in a staggered manner has been explained above.
, Y can also be applied.

(Example) Alumina ceramic piece (20X 20X 4 lll
5 part 20X IOX 4m+s) are arranged in a staggered arrangement, and at the contact area where the three chips touch (X in Figure 1), Ag-Cu is applied only to the part joined by the joining metal piece (copper, φ1OX0.5w). - Apply Tl-based active metal paste brazing material. A joining metal piece was placed on the ceramic and the metallizing was performed at the same time as the joining of the joining metal piece to produce a L20 x 140 x 4 ceramic joining plate as shown in Fig. 1 (the joining metal piece was a medium heat plate instead of a ring).

Compared to conventional full-surface bonding, the metallized area was reduced to about 115, and the number of bonding metal pieces used was also about 115. - Compared to spot bonding of large-area ceramics, the metallized area and the number of metal pieces to be bonded were large, but the cost of the ceramics was low.

The prepared ceramic bonded plate was applied to a fan blade. Among the metal pieces bonded to the ceramic bonding plate, apply silver brazing filler metal and flux to five metal pieces at the center and four corners, place them face down on a metal wing plate, and perform high-frequency brazing from the ceramic side using the equipment. The part where the brazing material was set was locally heated to perform brazing. Care was taken not to spend much time on bonding and to avoid heat effects between bonding spots.

There were no cracks in the ceramic, and a good joint was achieved.

Attached to the tip of the sending machine's 2m long blade, approximately 140m long
Hot air at about 200°C was continuously sent for 24 hours while rotating at a speed of /s. The centrifugal force caused by the rotation of a normal blower was small, and the strength of spot bonding was sufficient. At the same time, we also conducted comparative tests on full-surface bonding of small ceramic pieces and spot bonding of large-area ceramic sheets. There were no particular problems with the blades that were bonded over the entire surface of small pieces of ceramics, but with the spot bonding of two large-area ceramic pieces, the ceramics could crack due to distortion of the blades when the rotation speed became unstable and thermal distortion caused by heating. Has entered. The ceramic bonded plate according to the present invention is
It deforms following the deflection of the blade, and a slight gap opens between the small ceramic pieces due to the expansion of the joined metal pieces.
No cracking or falling off of the ceramics was observed.

(Effects of the invention) 1) Ceramic plates for metal bonding of any large area can be easily obtained by collectively connecting ceramic chips of a single standard, 2) Small ceramic chips are bonded to each other via a stress-buffering metal. Because of this structure, it is easy to absorb distortion due to differences in thermal expansion in gaps between chips. 3) Since the ceramics are bonded together to form a single piece, it is not necessary to bond all the metal pieces to the metal plate, and the metal pieces can be spaced apart at appropriate intervals to buffer stress. It is possible to obtain a composite material having excellent workability such as being able to be bonded, and having high bonding strength at a low cost.

[Brief explanation of drawings]

The figures show embodiments of the present invention, and Fig. 1 is a perspective view of a ceramic bonding plate in which rectangular ceramics of the present invention are arranged in a staggered manner, and Fig. 2 is a perspective view showing an example in which the same bolts are installed. It is. FIG. 3 shows an example in which the present invention is applied to a regular array of square chips, and FIG. 4 shows an example in which the invention is applied to a regular hexagonal chip. 1... Ceramic chip 2... Joining metal 3...
・Ceramics joint plate 4... Installation bolts a, b, c
, d...Example of ceramic chip

Claims (1)

[Claims] 1. In a ceramic bonding plate formed by connecting small pieces (chips) of ceramics, the ceramic chips are arranged in succession, and the parts where these chips contact each other are separated from each other by adjacent ones. A ceramic bonding board characterized by connecting and fixing with a bonding metal that spans the chip. 2. The ceramic bonded plate according to claim 1,
A ceramic bonding plate with bolts planted at predetermined intervals on the bonding metal installation surface. 3. A method for joining a ceramic joining plate and a metal plate, comprising fixing the ceramic joining plate according to claim 2 to a metal plate using bolts implanted in the joining plate. 4. When joining the ceramic bonding plate according to claim 1 with a metal plate, a brazing material is attached to one or all selected parts of a large number of bonding metals fixing the ceramic bonding plate, and the brazing material is attached. A method for bonding a ceramic bonding plate and a metal plate, which is characterized by bringing the surface into contact with the metal plate and locally heating it using high frequency waves.