JPH1071569A - Super abrasive grain sintered member, tool using it, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the strength of a bonding metal sintered body, while sufficiently holding the content of super abrasive grain without reducing the sharpness and provide a long-life member by sintering a metal piece and super abrasive of a specific concentration by HIP, providing a uniform organization, and setting a theoretical density rate to a specific % or more. SOLUTION: As for mix powder of a using material, diamond powder super abrasive of concentration 5-200 and mix powder of bonding metal powder are compression-molded into a ring shape. A material formed by inserting and assembling the ring embossed body 3 around the outer circumference of the central part of an iron cylinder 5 is sealed into a rubber cylinder and applied with CIP so that the ring embossed body 3 is compressed and fixed to the iron cylinder 5. A lot of compressed assemblies 13 are loaded in a capsule 9. The sealed capsule 9 is loaded in the HIP device and sintered so that the super abrasive grain sintered member whose component distribution of a bonding metal phase 16 is uniform across the whole section, density is uniform, and theoretical density ratio is 96% or more can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of sintering a metal piece and a superabrasive such as diamond, cubic boron nitride (CBN) or a mixture thereof with a metal powder such as a single metal powder or an alloy powder. The present invention relates to a super-abrasive grain sintered member integrally joined to a metal sintered body, a super-abrasive tool such as a saw, a grindstone, and a dresser using the same, and a method of manufacturing the same.

[0002]

2. Description of the Related Art As a method of manufacturing a superabrasive layer and a superabrasive tool, a mixture of a superabrasive and a binding metal powder or a mixture of the mixture and a base metal are charged into a mold, and then hot-pressed. (HP)
A method of sintering is well known.

[0003]

In the case of a superabrasive tool, for example, diamond beads 2 attached at intervals in the length direction of a wire in a wire saw 1 shown in FIGS. When cutting stones, concrete, etc., it is necessary that the bonding metal phase 16 sufficiently retains the diamond particles 4 and does not drop them. Then, as the cutting progresses, the surface of the beads 2 gradually wears out, and finally reaches the end of its life. Therefore, it is required that the surface of the beads 2 is hardly worn out and has a long life. It is also desired that the attrition be uniform throughout the beads. 7 (a) is a rubber coating, and (b) is AA of (a).
In the sectional view, reference numeral 5 denotes an iron cylinder serving as a support for attachment, and reference numeral 6 denotes a wire rope.

[0004] For the long life, it is necessary that the composition distribution and density of the binder metal phase 16 be uniform throughout, high in density, and high in mechanical strength. However, in the conventional manufacturing method using HP, mold costs and the like are bulky and costly, and at the time of sintering, the liquid phase of Cu and Sn flows out to the outermost layer, and as shown in FIG. Causes burrs,
As shown in Table 1, the composition distribution of the bonding metal phase 16 is often inhomogeneous. Since the uniaxial compression is performed in the vertical direction, in a thin-walled shape as shown in the figure, a density difference between the central portion and the upper and lower portions is likely to occur, and the average density of the whole is about 94.0% or more of the theoretical density. , And it is difficult to expect a sufficient improvement in strength.

[0005]

[Table 1]

On the other hand, as a method for producing a super-hard and high-hardness dense sintered body different from the object of the present invention, there is the following proposal using the HIP method.

One is disclosed in JP-A-3-150303.
In this method, a high temperature and a high pressure are applied to a raw material containing diamond or CBN as a main component and a small amount of binder metal powder by a HIP method using a BN powder compact. Another one is disclosed in Japanese Patent Application Laid-Open No. 5-61226, in which a large amount of periodic table Nos. 4a, 5a, 6a is added to diamond powder.
A raw material to which at least one of oxides, nitrides, carbides, and carbonitrides of group III transition metals, Si, B, and Al is added, similarly to HIP
It is said that a high hardness sintered body of Hv 800 or more is manufactured by applying high temperature and high pressure by the method.

[0008] In any of the above proposals, a statement showing the necessity and possibility of adopting the HIP method in a member made of a metal piece and a metal sintered body containing superabrasive grains, which are the object of the present invention. There is no point in suggesting a specific method for adoption. As a means for solving the above problems, the present inventors have completed the following new superabrasive sintered members based on the HIP method and a method for forming the same as a result of various trial production studies.

[0009]

The first feature of the superabrasive sintered member according to the present invention is that a metal piece and a metal sintered body containing a superabrasive having a concentration of 5 to 200 are sintered. A member integrally joined by sintering, the sintering is performed by HIP, the structure is homogeneous, and the theoretical density ratio is 96%.
That is all. And as the metal to be sintered,
Most preferably, it is a multi-phase non-ferrous metal with or without a filler such as W ₂ C.

[0010] Examples of the use of the super-abrasive sintering member include diamond beads for a wire saw, a pencil-edge type wheel, a saw blade, and the like, in which a metal part containing no super-abrasive acts as a tool base for supporting and mounting. Is preferred. Of course, it is also used as other grinding wheels and dressers.

The second characteristic of the superabrasive sintered member of the present invention having such characteristics is that it can be easily and economically manufactured by the following method. (1) A step of embossing and compressing a mixture obtained by adding superabrasive grains of 50 vol% or less to a bound metal powder, and a step of combining one or more of the compression molded bodies with a metal part prepared in advance. And cold isostatic compression (C
IP), temporarily fixing and charging into a capsule, filling in a pressure medium powder, depressurizing and sealing the inside of the capsule, and charging the capsule into a HIP device to perform HIP.
And a step of applying.

(2) A manufacturing method in which the combination is temporarily fixed at a relatively low temperature instead of being subjected to CIP and temporarily fixed.

(3) The metal piece is formed by a cylindrical body serving as a tool base for supporting and fixing the metal sintered body or a disk-shaped body provided with a concave portion on the outer peripheral end face, and is combined with this. A manufacturing method in which the molded body is formed into a second cylindrical body that can be inserted into the outer periphery of the cylindrical body or a fan shape that is fitted into a concave portion of the outer peripheral end surface.

(4) The porosity of the embossed compression molded article is 40
% Production method.

(5) One preferable method is to pre-compress the pressure medium powder to be filled in the capsule into a combination receiving shape corresponding to the shape, number and position of the combination to be charged. is there.

(6) Diamond, CB as super abrasive
N or a mixture thereof is used, and as the binding metal, a solid phase sintered with Co or the like is also used, but this is replaced with Ni, and further a liquid phase such as Cu, Sn, etc. is added thereto. It is preferable to use a multi-phase non-ferrous metal powder to which a metal or alloy powder that causes the above is added. If necessary, a filler such as W ₂ C can be added to the metal powder. (7) In a special case, the capsule is omitted, the combination of the compression molded body of the mixture of the super-abrasive grains and the binding metal powder and the metal piece is wrapped in a metal foil and sealed under reduced pressure. It is also possible to perform HIP by charging the battery. This sealed metal foil is placed in a capsule, embedded in a pressure medium powder, and
It is of course possible to apply IP.

The reason why the superabrasive powder to be mixed is set to 50 vol% or less is that the concentration of the superabrasive in a grindstone, a dresser, or a saw blade using the superabrasive is 200 or less even in an exceptionally high concentration. This is because it is usually lower than about 100. The present inventors have paid attention to the fact that in order to withstand the severe conditions of cutting stones, this diamond bead requires a particularly strong bonding metal phase, and the density of the bonding metal phase is determined by the method described above. To enhance and achieve its purpose.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The specific contents will be described below with reference to embodiments.

[0019]

(Example 1) An example of trial production of a diamond bead 2 for a wire saw shown in FIG. 5 will be described as Example 1 and Comparative Example 1. (1) Raw materials used Mixed powder Super-abrasive grains Diamond powder # 40 Content 0.5 ct / ke Bonded metal powder component (wt%) Co 81 Cu 6.3 Sn 2.7 W ₂ C10 Iron cylinder as support 5. Material SUM24L Cu plating thickness 10μm dimension [Figure 1 (b)] Height H10mm internal diameter D ₁ 3 mm outer diameter D ₂ 7 mm

The mixed powder is formed into a ring shape as shown in FIG. Height H ₁ Example 7 mm Comparative Example 7 mm Inner Diameter D ₃ Example 7.1 mm Comparative Example 7.1 mm Outer Diameter D ₄ Example 11.5 mm Comparative Example 10.5 mm Porosity Example 40% Comparative Example 40%

As shown in FIG. 1C, the ring-shaped press body 3 is inserted and fitted to the outer periphery of the central portion of the iron tube 5 and assembled. , 200k
g / cm ² and sintering for 120 minutes to form diamond beads 2 as shown in FIG. By compression sintering, the height H ₁ shrinks in 6.5 mm, the inner diameter D ₃ is joined fixed to the outer periphery of the iron cylinder 5, burrs 8 occurs by pressing on the outer diameter side. The burrs 8 cause the liquid phase at the time of sintering to flow out, which causes the distribution of the binding metal component to become non-uniform as described above. Further, the central portion in the height direction in which the burrs 8 are formed has a low degree of compression and a low density, and the theoretical density ratio as a whole is 94.0% and the hardness is HR.
B 97.2.

In the embodiment, the combination as shown in FIG. 1C is sealed in a rubber cylinder, CIP is applied, and the ring-shaped pressing body 3 is fixed to the iron cylinder 5 by compression. As a result of this compression, the outer diameter D ₄ takes on a small diameter portion of 11.3 mm as shown in FIG. Many of the compressed combinations 13
As shown in FIGS. 2 (a) and 2 (b), a capsule 9 made of a mild steel plate having a thickness of 2 mm is charged.

At the time of charging, as shown in FIG. 2, alumina powder of # 100 is well spread as the pressure medium powder 12, and embedded in the powder at intervals so that they do not directly contact each other. To After the embedding, the lid 10 was welded 14 to the capsule 9 as shown in (b), heated to 300 ° C. to blow off moisture, evacuated from the deaeration port 11 and tightened and sealed 15.

The sealed capsule 9 is charged into a HIP apparatus, and is sintered by holding at 850 ° C., 200 kg / cm ³ for 120 minutes, and the diamond beads 2 as shown in FIG.
Was formed. By the compression sintering, the height H ₁ is 6.5 mm, the outer diameter D ₄ is a large-diameter portion 10.6 mm, and the small-diameter portion 10.3 mm has a shroud shape,
Burrs do not occur. As shown in Table 2, the component distribution of the bonded metal phase was uniform over the entire cross section as compared with that of HP, the density was uniform, the theoretical density ratio was 97.4%, and the hardness was HRB 103.1.

[0025]

[Table 2]

[0026] Diamond bead 2 of the above Examples and Comparative Example, respectively subjected to barrel polishing, deburring for what remains burr, the inner diameter D ₂ of the iron cylinder 5
The deformed member was subjected to inner diameter processing, and inserted into the wire rope 6 with a space therebetween to produce a wire saw 1 as shown in FIG.

When a cutting test of reinforced concrete was carried out using this wire saw, as shown in FIG. 4, the degree of wear of the outer diameter of the diamond beads 2 with the increase in the cutting area was not constant, but in the embodiment, In many cases, the number was smaller, and as a result, the total wear amount of the example was about half that of the comparative example, and the life was nearly doubled. The outer diameter of the wire saw is apt to cause uneven wear.
It was estimated that the life was exceeded when the ratio exceeded / 2.

When comparing the manufacturing equipment cost and the operating cost between the comparative example and the example, the example shows that the largest mold cost in the comparative example is reduced to less than half, depending on the scale and the operation rate. And is much more economical. And, as described above, the resulting member has excellent characteristics.

Further, in the above embodiment, the sintered product subjected to barrel polishing is shown. However, unlike the comparative example, the outer surface of the diamond bead 2 is formed in direct contact with the pressure medium powder by sintering. Therefore, since the tip of the diamond particle 4 is exposed, it can be omitted. The reason why the porosity of the compression-molded product is set to about 40% is that if it is less than this, the pressing work is liable to be hindered, and the die is severely worn. This is because operations such as handling are difficult. The application of the CIP is important for improving the operability, particularly for maintaining and fixing the combined shape of the combination of the ring-shaped press body 3 and the iron tube 5, which is HI.
It also leads to ease of P.

The inner diameter of the iron tube 5 was modified by cutting the deformation caused by HIP, but a round bar was used for the iron tube.
If this is replaced with a hole forming process after the HIP, the material cost and the processing cost can be further reduced. In this case, it is important to provide an indication such as a conical recess indicating the center point of the hole processing on the upper and lower end surfaces of the round bar.

The alumina powder of # 100 is shown as the pressure medium powder. However, any powder that does not deform and react during sintering may be used. Therefore, boron nitride (BN), graphite, SiC,
Moderate grain size such as SiO, SiO ₂ or foundry sand,
Alternatively, a mixture of these materials having good heat conductivity and low flow resistance may be selected and used. In addition, in the embodiment, after being buried in the pressure medium powder, it was heated to 300 ° C. and degassed.
It may be heated to 0 ° C. or higher.

As the HIP device, a device having a heating temperature of 1200 ° C. using argon, a pressure of 500 kg / cm ² , and a charging volume of 500 cm ² × 100 cm was used, but other specifications may of course be used. The HIP in the present invention is not limited to purely theoretical hot isostatic compression (HIP), but includes pseudo-HIP.
According to IP, the liquid phase infiltration in sintering is also performed uniformly, so the strength of the sintered body can be measured by reducing the compounding ratio of the liquid phase product, and the performance of superabrasives may deteriorate. It is also possible to increase the sintering temperature and pressure within a range not to shorten the sintering time and to improve the strength of the sintered body by solid phase sintering.
In the embodiment, Cu plating is applied to promote sintering bonding with the iron tube 5, but this may be omitted.

In the above embodiment, the combination was embedded in the pressure medium powder in the capsule 9. However, in some cases, this powder was previously adjusted to the shape, number and position of the combination. It is also possible to form a plurality of combined receiving-type compression bodies so as to form a receiving die, and to fill the receiving die.

(Example 2) Next, in the production of diamond beads 2 similar to the above-mentioned example, of the components of the ring-shaped embossed body 3, Co of the binding metal powder component was replaced with Ni, and the embossed body was replaced with Ni. A description will be given of a second embodiment in which the combination of the steel 3 and the iron tube 5 is fixed by low-temperature temporary sintering instead of compression-fixing by CIP.

A ring-shaped embossed body 3 having a theoretical density ratio of about 66% formed by a mechanical press as shown in FIG.
As shown in (c), it is inserted and fitted around the outer periphery of the central portion of
As shown in the schematic diagram of FIG. 3, a large number of the grooves are formed in the grooves 18 of the carbon plate 17 having the stepped grooves 18 along the shape of the combination 13.

The carbon plate 17 is inserted into a sintering furnace while maintaining the arrangement state, that is, the state in which the ring-shaped embossing body 3 is inserted and fitted in the upper central portion of the outer periphery of the iron tube 5 by the upper groove 18. After holding at 750 ° C. for 90 minutes at atmospheric pressure under an inert atmosphere, about 9
The mixture was gradually cooled in 0 minutes to obtain a temporarily sintered combination 13.

The theoretical density ratio of the portion of the ring-shaped stamping body 3 is increased to about 75% by pre-sintering, and the combination 13 contracts as shown in FIG. Is temporarily fixed by being adhered to the outer periphery.

Although the above-mentioned temporary sintering is mainly performed for temporary fixing, it is more excellent in facilities, man-hours and safety and is more suitable for mass production as compared with the case of performing the CIP in the first embodiment.

The temporary sintering temperature depends on the composition of the embossing body 3. However, if the temperature is lower than about 700 ° C., the temporary sintering may be insufficient, and if it is higher than about 800 ° C., cracks may occur. Therefore, the temperature range during this period is preferable.

The pre-sintered combination 13 was placed in a capsule 9 as shown in FIG. 2, embedded in a pressure medium powder 12, and degassed and sealed 15, as in the first embodiment.

The sealed capsule 9 is charged into a HIP device, and 950 is heated at a temperature higher than the preliminary sintering temperature by about 100 ° C. or more.
At ° C., subjected to HIP holds 500kg / cm ^2, 120 minutes. By this HIP, the ring-shaped embossed body 3 became a sintered metal binding phase 16 having a theoretical density ratio of about 100%.

Using the diamond beads 2 formed by applying the above HIP, a wire saw 1 was manufactured in the same manner as in Example 1, and a cutting test was performed. It was found that the cutting speed was excellent by about 30% less than that of the comparative example (HP product) in Example 1.

(Embodiment 3) FIG. 6 is a schematic view showing a trial production example of a pencil edge type diamond wheel.
(B) is a side view of the fan-shaped pressing body 19 and its AA sectional view. (C) and (d) show the fan-shaped pressing body 19,
FIG. 3 is a side view showing a state where the wheel body 20 is fitted into a concave portion 21 provided on an outer peripheral edge of the wheel body 20 and a cross-sectional view taken along a line BB of FIG.

The outer diameter of the steel wheel body 20 is 204
mm, the thickness T of the outer peripheral portion is 15 mm, and the fan-shaped pressing body 19 for forming the abrasive surface on the outer peripheral edge is obtained by dividing the abrasive surface into 20 equal parts.
It was decided to form zero.

This sector-shaped pressing body 19 is obtained by combining a bonded metal powder (Co90, Cu7.5, Sn2.5 wt%) containing 2.2 ct / cm ³ of ♯40 / 50 diamond powder by mechanical pressing with a theoretical density ratio of 65%. % By compression molding. The obtained fan-shaped pressing body 19 is inserted into and closely fitted to the recess 21 of the wheel body 20 and temporarily fixed as shown in FIGS.

In the same manner as in the above embodiment, the above-mentioned combination was charged into a capsule 9, embedded in a pressure medium powder 12, sealed by degassing, and charged into a HIP device at 830 ° C. and 200 kg / kg.
cm ^2, 120 minutes holding sintering, to obtain a diamond wheel pencil edge type.

The shape and position of the fan-shaped pressing body 19 are maintained as set by the recesses of the wheel body 20 during the HIP processing, so that a pencil-edge type diamond wheel as designed can be easily obtained. In the above description, a pencil-edge type diamond wheel having a concave cross section of the sector-shaped pressing body 19 has been described.
The same applies to diamond wheels 9 having a convex cross section.

[0048]

As described in the above sections, according to the present invention, homogeneous and high-density sintering can be easily performed.
The strength of the bonded metal sintered body can be increased, and a long-life member can be provided, while maintaining the content of the superabrasive grains sufficiently so as not to reduce the sharpness.

[0049]

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional side view showing a production process of a diamond bead in Example 1, (a) is an iron cylinder, (b)
Is a pressed compact of a mixture of diamond powder and binding metal powder,
(C) is the combination of (a) and (b), (d) is (c)
(C), and (D) shows HI
(F) shows a state in which (C) is directly stamped and sintered by HP.

FIGS. 2 (a) and 2 (b) are a vertical cross-sectional view and a schematic side view illustrating a state in which the molded article of FIG. 1 (d) is inserted into a capsule and sealed.

FIG. 3 is a schematic perspective view illustrating a state of a carbon plate on which a combination is arranged according to a second embodiment.

FIG. 4 is a table showing the state of outer diameter wear caused by cutting reinforced concrete in Comparative Example 1 and Example 1.

FIGS. 5A and 5B are a side view illustrating a configuration of a wire saw and a schematic diagram of an AA cross section thereof.

FIGS. 6A and 6B are schematic views for explaining a third embodiment; FIGS.
FIG. 3 is a side view and a sectional view taken along the line AA of the fan-shaped pressing body, and FIGS. 3C and 3D are a side view and a sectional view taken along the line BB of the wheel body.

[Explanation of symbols]

1. Wire saw 20. 1. Wheel body (metal parts) 2. Diamond beads 21. 20 recesses 3. 3. Ring-shaped embossed body (compression molded body) Diamond grains 5. Iron tube (metal piece) 6. Wire rope 7. Rubber coating 8. Burr 9. Capsule 10. Lid 11. Deaeration port 12. Pressure medium powder 13. Combination 14. Welding 15. Sealed 16. Binder metal phase containing superabrasive grains 17. 18. Stepped groove of carbon plate 18.17 Sector-shaped pressing body (compression molded body)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Koji Kusada, Inventor 2-80, Hokita-cho, Sakai-shi, Osaka Inside Osaka Diamond Industry Co., Ltd. (72) Kensaku Sasaki 2-80, Horikita-cho, Sakai-shi, Osaka Osaka Diamond Industry Co., Ltd.

Claims (10)

[Claims] 1. A member in which a metal piece and a metal sintered body containing superabrasive grains having a concentration of 5 to 200 are joined together by sintering, wherein the sintering is performed by hot working or the like. Compression (HIP)
The structure is homogeneous and the theoretical density ratio is 96%
A superabrasive sintered member characterized by the above. 2. The member according to claim 1, wherein the metal sintered body is formed of a multiphase non-ferrous metal containing or not containing a filler by liquid phase sintering. 3. The super-abrasive grain sintered member according to claim 1, wherein the metal part is a tool base for supporting and fixing the metal sintered body, and the outer surface of the metal sintered body is a ground surface, or A super-abrasive tool characterized by being used with additional processing. 4. The tool according to claim 3, wherein the superabrasive tool is one of the following A, B and C. A. The metal part is a bead having a cylindrical shape, and the metal sintered body is integrally joined to the outer periphery of the cylindrical shape to form an outer peripheral abrasive surface. B. The beads described in A are inserted through the wire rope,
A saw wire fixed at intervals in the length direction. C. The metal piece has a disk shape with a concave portion on the outer peripheral end surface,
A wheel or saw blade in which a plurality of metal sintered bodies are joined together in a disc-shaped concave portion continuously or at intervals to form an abrasive surface. 5. A step of stamping and compression molding a mixture obtained by adding 50 vol% or less of superabrasive grains to a binder metal powder containing or not containing a filler, and one or more of the compression-molded articles and a metal part. And combining the combined product as it is,
Alternatively, after adding cold isostatic pressing (CIP), charging the capsule into a capsule and burying it in a pressure medium powder; depressurizing and sealing the capsule; and loading the capsule into a HIP device. The method for producing a superabrasive sintered member or a superabrasive tool according to claim 1 or 2, further comprising a step of performing HIP. 6. The method according to claim 5, wherein the sintering is performed in place of adding CIP to the combination, and the HIP is performed at a temperature higher than the sintering temperature. A method for producing a superabrasive member or a superabrasive tool according to claim 3. 7. The method according to claim 5, wherein the porosity of the compression-molded body is set to about 40%. 8. The pressure medium powder for filling the combination is pre-compressed and formed into a combination receiving shape corresponding to the shape, the number of charging, and the position of the combination. Item 8. The production method according to Item 7. 9. The super-abrasive grains are diamond, the binding metal powder is a multi-phase non-ferrous metal powder, and the sintering is liquid phase sintering. Manufacturing method. 10. A step of sealing a combination of a compression molded body of a mixture of superabrasive grains and a binding metal powder and a metal part or a metal compact with a metal foil, and placing the sealed substance in a capsule. The method according to claim 1, further comprising the steps of: charging, burying in a pressure medium powder, sealing, and then charging the HIP device to apply HIP. 5. Manufacturing method of abrasive grain sintered member or super abrasive tool.