JPH0780709A - Ceramic cutting tool and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a ceramics-made cutting tool, capable of sufficiently coping with the cutting of high strengtn graphite cast iron and excellent in abrasion resistance and chipping resistance; and a manufacturing method thereof. CONSTITUTION:This tool is a ceramic cutting tool composed of Al2O3 of 5-30wt.% ZrO2 of 1-12wt.% an SiC whisker of 3-40wt.%, and the rest of TiC having a mean particle diameter of actually 2mum. A mean diameter and length of the SiC whisker are 0.1-1mum and 2-50mum, and 50% or more of the SiC whisker has alpha-type or beta-type crystal structure respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic cutting tool and a method for manufacturing the same, and more particularly, it comprises a multi-reinforced titanium carbide-alumina-zirconia-silicon carbide whisker, which has high fracture resistance and wear resistance at high speed cutting. An excellent cutting tool and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years,
Cutting technology has undergone a marked revolution due to the high precision and high functionality of machine tools. Also in the cutting industry,
Along with this, there is a strong demand for higher efficiency and accuracy, especially for higher efficiency. Especially in the automobile industry, there is a tendency toward weight reduction, and there is a tendency to take measures to reduce the wall thickness by using high-strength materials. Therefore, the work material is also strengthened and is one of the important raw materials. Spheroidal graphite cast iron also has a tensile strength of 40 kg / mm ² (FCD40) level of 60 kg /
mm ² (FCD60), 70 kg / mm ² (FCD7
0), and even 100 kg / mm ² (FCD100) level is beginning to appear. Therefore, it is required to cut a high-strength work material at a higher speed, and the demand for tool performance is becoming more severe.

Generally, as a tool material, a cemented carbide or cermet in which WC or TiC is bonded with a metal such as Co or Ni,
Further, those whose surfaces are coated with chemically stable Al ₂ O ₃ or the like, and further, ceramics having excellent high temperature characteristics such as Al ₂ O ₃ , Al ₂ O ₃ —TiC, Si ₃ N ₄ and Al ₂ O.
_3- SiC whisker ceramics are used. However, when attempting to cut the spheroidal graphite cast iron having a tensile strength of 60 kg / mm ² or more using a ceramics tool, the Al ₂ O ₃ or Al ₂ O ₃ —TiC-based tool is damaged,
SI ₃ N ₄ and Al ₂ O ₃ —SiC whisker-based tools have a problem of wear due to reaction. In this way, the current situation is that the current ceramic cutting tools have not been used in a satisfactory state. Therefore, cutting of these high-strength spheroidal graphite cast iron is performed at a relatively low speed using a coding tool or a cermet tool, and therefore high-speed cutting is possible and a cutting tool with excellent wear resistance and fracture resistance. There is a strong need for.

As a cutting tool for the purpose of cutting spheroidal graphite cast iron, a composite ceramic in which Al ₂ O ₃ is added to an iron-based work material with TiC as a matrix having excellent high temperature hardness from the viewpoint of wear resistance is used. Some are on the market. Besides this, not only Al ₂ O ₃ but also composite ceramics reinforced with SiC whiskers are being investigated.
The reality is that it has not yet reached the level of practical use.

For example, Japanese Patent Application Laid-Open No. 61-26564 discloses that
In TiC-Al ₂ O ₃ composite ceramics, MgO,
A manufacturing method is disclosed in which a sintering aid such as CaO, SiO ₂ , ZrO ₂ , or NiO is added, and sintering is performed from a raw material in which a part of TiC is replaced with Ti. Also, JP-A-63-22
The No. 5579, the TiC-Al ₂ O ₃ -SiC whisker composite ceramics, MgO, CaO, SiO _2, Zr
A ceramic tool material to which a sintering aid such as O ₂ , NiO, Y ₂ O ₃ or AlN is added, or a part of TiC is Ti, or a carbide, nitride, or oxide of IVa group, Va group, or VIa group, Ceramic tool materials substituted with one selected from borides are disclosed.

However, according to the research conducted by the present inventors, the TiC-Al ₂ O ₃ composite ceramic disclosed in Japanese Patent Laid-Open No. 61-26564 is still insufficient in fracture resistance. Further, in Japanese Patent Laid-Open No. 225579/1988, a TiC having a particle diameter of 1 to 2.5 μm is used as a raw material and a hot press sintering method is applied to 1800
Only sintering at a sintering temperature of 1950 ° C. is disclosed. In such a manufacturing method, the particle size of the TiC matrix is relatively coarse, and in the case where high-strength spheroidal graphite cast iron is cut at a high speed, sufficient wear resistance is not actually obtained.

[0007] Therefore, an object of the present invention is to provide a ceramic cutting tool having excellent wear resistance and chipping resistance capable of sufficiently cutting high-strength graphite cast iron, and a method for manufacturing the same.

[0008]

As a characteristic evaluation as a cutting tool, taking the wear of the flank in a cutting test using an iron-based material as a work material as an example, Katsumura et al. Powder Metallurgy "(Journal of the Japan Society
of Powder and Metallurgy, vol. 137, N
o. 7, 1082-1087, 1990), a cutting tool made of Al ₂ O ₃ —SiC particles has better wear resistance than a cutting tool made of Al ₂ O ₃ —SiC whiskers. ing. This seems to mean that the ceramic structure in the cutting tool material should be as fine as possible with respect to the improvement of wear resistance.

[0009] One of the inventors of the present invention is "boundary".
(Vol. 5, No. 8, pages 44 to 47, 1989), Al ₂ O ₃ —ZrO ₂ —SiC whisker composite ceramics contains Zr during the sintering process.
O ₂ tends to come into contact with SiC whiskers, and when using a ZrO ₂ raw material having sufficiently fine primary particles, SiC
It is observed that the whiskers are distributed in a size corresponding to the diameter of the whiskers. Considering the fine dispersion of ZrO ₂ , it is preferable that the SiC whiskers have a small diameter.

On the other hand, if whiskers are introduced into ceramics to form a composite, basically, high toughness can be achieved. F. Beocher et al., "Journal of America
n Ceramic Society "(vol.71, No.12, 1
As is reported in (pp. 050-1061, 1988), the increase in fracture toughness ΔK of whisker reinforced ceramics (composite) is generally expressed by the equation ΔK = σ _f [V _f · r · E ^c · G ^m / 6 ( 1-ν ² ) E
^w · G ⁱ ] ^1/2 . Where σ _f is the breaking strength of the whiskers, V _f is the volume fraction of the whiskers, r is the radius of the whiskers, E ^c is the Young's modulus of the composite, and G ^m is the strain energy release of the matrix. Is the velocity, ν is the Poisson's ratio of the composite, E ^w is the Young's modulus of the whiskers, and G ⁱ is the strain energy release rate of the whiskers / matrix interface.

According to this equation, if the blending amount of whiskers is the same (volume ratio), the fracture strength of the whiskers is high, and the fracture toughness of the ceramic composite is improved as the whisker diameter is increased.

However, in reality, there may be defects inside the whiskers. Kelly's “Strong
As described in Solids "(Oxford University Press, 1966), it is expected that the smaller the diameter of the whiskers, the smaller the probability of having internal defects and the greater the strength.

Further, as described in the above-mentioned book, the high-strength whiskers have an essentially smooth surface. Comparing two crystal types of α-type (hexagonal) and β-type (cubic) in the SiC whiskers, the α-type whiskers growing in the c-axis direction tend to have a smoother surface. Further, the β type also has a lot of stacking faults (irregularities) in the growth direction (in the x-ray diffraction pattern, the peak of 2θ = 41.4 °, which appears in a normal β type crystal, does not appear, and 2θ = 33.6 ° Peak appears)
It has been observed that the product has excellent straightness and has a smooth surface. Such whiskers have higher strength than ordinary whiskers having a β-type crystal structure.

As a result of earnest research on the cutting tool in consideration of the above points, the present inventors
A system in which Al ₂ O ₃ , ZrO ₂ and SiC whiskers are introduced is selected. As SiC whiskers, SiC is used from the viewpoint of chipping resistance.
The whisker itself has a high fracture strength, that is, it is basically an α type or a β type that has many irregularities, and from the viewpoint of wear resistance, the structure of the ceramic composite is selected. Is made as fine as possible, that is, fine TiC, Al ₂ O ₃ , and ZrO ₂ raw material powders and a small diameter.
It has been discovered that a ceramic cutting tool excellent in fracture resistance and abrasion resistance can be obtained by using SiC whiskers and by finely controlling the sintering conditions in the production thereof to form a fine ceramic structure. The present invention was conceived.

That is, the ceramic cutting tool of the present invention comprising TiC, Al ₂ O ₃ , SiC whiskers and ZrO ₂ is
Al ₂ O ₃ is 5 to 30% by volume, ZrO ₂ is 1 to 12% by volume
The SiC whiskers are 3 to 40% by volume, and the balance is substantially composed of TiC having an average particle size of 2 μm or less. The SiC whiskers have an average diameter and an average length of 0.1 to 1 μm, respectively.
m and 2 to 50 μm, and 50% or more of the SiC whiskers have an α-type crystal structure or a β-type crystal structure.

The method for producing a ceramic cutting tool according to the present invention comprises (a) TiC powder having an average particle size of 1 μm or less, (b) Al ₂ O ₃ powder having an average particle size of 1 μm or less, and (c) ZrO ₂ Powder, and (d) average diameter and average length are 0.1-1μ each
m and 2 to 50 μm, and using 50% or more of a raw material powder containing SiC whiskers having an α type crystal structure or a β type crystal structure, a temperature of 1500 to 1800 ° C. and 150 to 500 kg / cm ² It is characterized by performing pressure sintering for 30 minutes to 10 hours under the pressure of.

The present invention will be described in detail below.

In the present invention, the average diameter is 0.1 to 1 μm.
Then, a SiC whisker having an average length of 2 to 50 μm is used. If the average diameter of the SiC whiskers is less than 0.1 μm,
If the toughness and strength are not sufficiently improved, and if the toughness and strength are larger than 1 μm, the fine structure of the composite ceramic is not so fine, resulting in poor wear resistance.
If the average length of the SiC whiskers is less than 2 μm, the strength of the whiskers will not be sufficiently improved. On the other hand, if the average length exceeds 50 μm, the probability of introducing defects into the sintered body increases, and thus the strength of the composite decreases.

Preferably, the average diameter is 0.2 to 0.8 μ.
m, more preferably about 0.4 to 0.6 μm and having an average length of 10 to 40 μm, more preferably about 30 μm.
Use C whiskers.

Further, in the present invention, at least 50% or more of the SiC whiskers used have an α-type crystal structure or a peak at 2θ = 33.6 ° in the x-ray diffraction pattern, and 2θ = 41.4 °. Β which has substantially no peak at
Type crystal structure, that is, a β type crystal structure having many stacking faults (irregularities) in the growth direction. α
If the content of SiC whiskers having a crystal structure of γ-type or a β-type crystal structure with many irregularities is less than 50%, the strength and toughness of the cutting tool are not improved. Preferably Si
80% or more of C whiskers are α-type or β-type with many irregularities.

As will be described later, although ZrO ₂ is dispersed in the ceramic matrix of the present invention, since ZrO ₂ tends to disperse in contact with SiC whiskers, it is relatively small as described above. By using the SiC whiskers, the dispersed state of ZrO ₂ is also improved, and a composite ceramic having a fine structure can be obtained. As a result, the wear resistance of the cutting tool is significantly improved.

In the present invention, Al ₂ O is added to the TiC matrix.
₃ , ZrO ₂ and SiC whiskers are compounded at the same time, and the toughness of ceramics can be increased by multi-toughing. Al
The composite of ₂ O ₃ brings about a toughening effect of crack interaction (crack deflection or crack bowing) due to the dispersion of the second phase. It also acts as a sintering aid for TiC. High Toughness mechanism of ZrO ₂ is due to the energy of destruction by transformation ZrO ₂ (transformation from cubic to monoclinic martensite) (crack energy upon the occurrence of) is absorbed. In addition, the compressive stress to the whiskers becomes large in the ZrO ₂ transformation region behind the crack (behind the crack tip with respect to the running direction of the crack), and the additional effect of strengthening the bridging mechanism of the whisker is obtained. To be Further, the composite of Al ₂ O ₃ and ZrO ₂ enables low temperature firing, suppresses grain growth of the matrix, and achieves finer structure.

Raw material powders of TiC, Al ₂ O ₃ and ZrO ₂ are
In order to make the ceramic matrix as fine as possible from the viewpoint of improving wear resistance, the average particle size is 1 μm or less. When the raw material powder having a particle size of 1 μm or more is used, the structure of the composite ceramic becomes coarse and the wear resistance becomes poor. Preferably, a raw material powder having an average particle size of TiC of 0.2 to 0.5 μm is preferably used.

The composition of each component is as follows. Ti
The total of C, Al ₂ O ₃ , ZrO ₂ and SiC whiskers is 10
As 0% by volume, Al ₂ O ₃ is 5 to 30% by volume, ZrO ₂ is 1 to 12% by volume, SiC whiskers are 3 to 40% by volume, and the balance is substantially TiC.

When Al ₂ O ₃ is less than 5% by volume, the toughness due to the crack interaction is not sufficient, and it becomes difficult to obtain a dense composite ceramic forming a cutting tool.
On the other hand, when Al ₂ O ₃ is blended in an amount of more than 30% by volume, the amount of TiC, which is relatively excellent in high temperature hardness, decreases, so that the wear resistance of the cutting tool decreases. Preferably Al ₂ O
The amount of ₃ is 10 to 25% by volume.

If ZrO ₂ is less than 1% by volume, the toughness and strength of the finally obtained composite ceramic cannot be expected to increase. Further, the fineness of the ceramic structure becomes insufficient and the wear resistance becomes poor. On the other hand, ZrO
_{When 2} is blended in an amount exceeding 12% by volume, the hardness of the composite ceramic is lowered and the cutting tool does not have sufficient wear resistance. Preferably, the amount of ZrO ₂ is 2-10% by volume.

Further, if the amount of SiC whiskers is less than 3% by volume, the strength and toughness of the composite ceramic forming the cutting tool will not be sufficiently improved. On the other hand, when the SiC whiskers in an amount exceeding 40% by volume are blended, the wear resistance of the cutting tool is lowered due to the reaction with the spheroidal graphite cast iron of the work material.
Preferably, the SiC whiskers are 8 to 35% by volume.
Among them, 8-20% by volume when the wear resistance is important,
When emphasizing chipping resistance, it is 20 to 35% by volume.

The average grain size of TiC in the ceramics obtained by sintering the raw material having the above component ratio is preferably 2 μm or less. If the average particle size exceeds 2 μm, the wear resistance decreases. In addition, in order to make the average particle diameter of TiC in the ceramics 2 μm or less, sintering may be performed by a manufacturing method described later using a raw material powder having the above-described amount and having an average particle diameter of 1 μm or less.

Next, a method of manufacturing the TiC-Al ₂ O ₃ -ZrO ₂ -SiC whisker composite ceramics will be described.

First, the raw material TiC powder, Al ₂ O ₃ powder,
A predetermined amount of ZrO ₂ powder and the above-specified SiC whiskers are taken and mixed. It is preferable that the mixing is sufficiently performed (for example, 48 hours or more) using a ball mill or the like. When starting with a raw material powder having an average particle size of 1 μm or more, first use Ti
C powder, Al ₂ O ₃ powder, and ZrO ₂ powder may be sufficiently crushed with an attritor, etc., and then SiC whiskers may be added and mixed with a ball mill.

Further, this mixed powder was mixed with Mg as a sintering aid.
Oxides such as O, CaO, SiO ₂ , Y ₂ O ₃ , NiO, and TiO ₂ may be added.

As the raw material ZrO ₂ , Y
₂ O _3, CaO, may be used as the partially stabilized with HfO ₂ or the like.

Next, after drying the obtained mixed powder, it is put into a mold having a desired shape and pressure-baked at 1500 to 1800 ° C. for 30 minutes to 10 hours while applying a pressure of 150 to 500 kg / cm ^2. To conclude.

The pressure is less than 150 kg / cm ² at a sintering does not densification enough for practical use as a cutting tool. Further, even if the pressure exceeds 500 kg / cm ² , there is no difference in effect, so the upper limit is made 500 kg / cm ² .

On the other hand, if the sintering temperature is less than 1500 ° C., densification of ceramics cannot be achieved. Further, when the sintering is performed at a temperature higher than 1800 ° C., the TiC matrix grows grains, and it is not possible to achieve a fine crystal structure, and as a result, the wear resistance decreases. As described above, in the method of the present invention, it is important to carry out the sintering at a relatively low temperature, which allows TiC in the ceramics.
The average particle size of the matrix is preferably suppressed to 2 μm or less.

If the sintering time is less than 30 minutes, densification of ceramics cannot be achieved. On the other hand, if the sintering time exceeds 10 hours, the TiC matrix will undergo grain growth and wear resistance will decrease.

Next, the obtained sintered body is ground by a known method to produce a target cutting tool.

[0038]

The present invention will be described in more detail with reference to the following specific examples.

Example 1 60% by volume of TiC (average particle size 0.27 μm), α-Al
₂ O ₃ (average particle size 0.7 μm) is 10% by volume, Y ₂ O ₃
Partially stabilized ZrO ₂ (average particle size 0.4
5% by volume, and SiC whiskers (average diameter 0.4 μm, average length 30 μm, α-type crystal ratio (α
/ (Α + β)) 85%) was mixed at 25% by volume, and the mixed powder was wet-mixed for 96 hours with a ball mill and dried.

Using the obtained mixed powder, at 1650 ° C. in an argon gas stream while applying a pressure of 450 kg / cm ^2.
Pressure sintering was performed for an hour to obtain a sintered body of 90 mmφ × 6 mm.

From the obtained sintered body, the model number SNGN120
A cutting tip having a shape of 408 was cut out and ground.

Using the cutting tip obtained above, a cutting test was conducted under the following cutting conditions (cutting condition 1).

Cutting condition 1 Work material: FCD70 Cutting speed: 180 m / min Feed: 0.4 mm / rotation Depth of cut: 1 mm Holder: FN11R-44A Cutting agent: Not used

The flank wear width (V _a ) after cutting for 4 minutes was 0.06 mm.

A cutting test was conducted on the cutting tip under the following conditions (cutting condition 2).

Cutting condition 2 Work material: FCD60 Cutting speed: 300 m / min Feed: 0.1 mm / rotation Depth of cut: 1.5 mm Cutter: CSBRN2525 (150 mmφ, single blade test) Cutting agent: Not used

The flank wear width (V _a ) when cutting 250 mm by 3 passes was 0.18 mm in this cutting tip.

Example 2 Average diameter 0.8 μm, average length 20 μm, peak at 2θ = 33.6 ° in x-ray diffraction pattern, 2θ =
A cutting tool made of composite ceramics was produced in the same manner as in Example 1 except that SiC whiskers having a β-type crystal structure having substantially no peak at 41.4 ° were used.

The cutting tip was subjected to a cutting test under the cutting condition 1 of Example 1, and the flank wear width after cutting for 4 minutes was measured and found to be 0.05 mm.

In addition, for this cutting tip, Example 1
The cutting test was performed under the cutting condition 2 of No. The flank wear width (V _a ) when 250 mm was cut by 3 passes was 0.16 mm in this cutting tip.

Comparative Example 1 For comparison, a cutting tool made of composite ceramics was produced in the same manner as in Example 1 except that TiC having an average particle size of 1.8 μm was used.

The cutting tip was subjected to a cutting test under the cutting condition 1 of Example 1 to measure the flank wear width after cutting for 1 minute. The result was 0.18 mm.

In addition, for this cutting tip, Example 1
When a cutting test was conducted under cutting condition 2 of
Was lost in one pass.

Table 1 shows the average diameter of the SiC whiskers used in Examples 3 to 5 and Comparative Examples 2 to 11 , the ratio of crystal forms, and the amounts of TiC, Al ₂ O ₃ , ZrO ₂ and SiC whiskers to be compounded. T is the same as in Example 1 except that
The cutting tip made of _{iC-Al 2 O 3 -ZrO 2} -SiC whisker composite ceramic was produced.

Table 1 TiC Al ₂ O ₃ Zr O ₂ SiC whisker compounding compounding compounding compounding compounding average diameter α / (α + β) Example No. (volume%) (volume%) (volume%) (volume%) (μm) (% ) example 3 60 20 10 10 0.4 85 example 4 50 25 5 20 0.4 85 example 5 55 10 5 30 0.4 85 Comparative example 2 68 2 5 25 0.4 85 Comparative example 3 35 35 5 25 0.4 85 Comparative Example 4 65 10 0 25 0.4 0.4 85 Comparative Example 5 50 10 15 25 0.4 0.4 85 Comparative Example 6 83 10 5 2 0.4 85 Comparative Example 7 40 10 5 45 0.4 85 Comparative Example 8 50 25 5 20 1.5 90 Comparative Example 9 50 25 5 20 0.5 0.5 Comparative Example 10 50 25 5 20 20 1.8 0 Comparative Example 11 50 25 5 20 20 0.3 30

A cutting test was performed on the obtained cutting tip under the cutting conditions 1 and 2 of Example 1. Under cutting condition 1 of this test, flank wear width after cutting for 4 minutes,
Under cutting condition 2, the flank wear width after cutting 250 mm for 3 passes was measured. The results are shown in Table 2.

Table 2 Example of flank wear width (mm) No. Cutting condition 1 Cutting condition 2 Example 3 0.04 0.19 Example 4 0.06 0.18 Example 5 0.08 0.20 Comparative example 2 0.16 0.38 Comparative example 3 0.20 0.32 Comparative example 4 0.08 Two-pass defect Comparative example 5 0.26 0.45 Comparative example 6 0.07 One-pass defect Comparative example 7 0. 14 0.35 Comparative Example 8 0.19 0.29 Comparative Example 9 0.112 Two-pass defect Comparative Example 10 0.28 0.69 Comparative Example 11 0.15 Two-pass defect

Examples 6 to 8 and Comparative Examples 12 to 17 Cutting chips were produced in the same manner as in Example 1 (with the same composition as in Example 1) except that pressure sintering was carried out under the conditions shown in Table 3. did.

The obtained cutting tip was subjected to a cutting test under the same conditions as the cutting condition 2 in Example 1. In this cutting test, the flank wear width after cutting 250 mm for 3 passes was measured. The results are also shown in Table 3.

Table 3 Pressure Sintering Pressure Sintering Pressure Sintering Flank Surface Temperature Pressure Time Wear Width Example No. (° C) (kg / cm ² ) (hours) (mm) Example 6 1550 450 10.0. 19 Example 7 1650 350 1 0.20 Example 8 1750 450 1 0.20 Comparative Example 12 1450 450 1 1 One-pass defect Comparative Example 13 1850 450 1 0.39 Comparative Example 14 1650 450 0.25 One-pass defect Comparative Example 15 1650 450 12 Two-pass defect Comparative Example 16 1650 100 1 One-pass defect Comparative Example 17 1650 600 1 0.18

Examples 9 to 13 and Comparative Examples 18 to 22 The cutting chips obtained in Examples 1 to 5 ( Examples 9 to 1 in that order).
3) and the cutting chips obtained in Comparative Examples 1, 8, 10, 13, and 15 (Comparative Examples 18 to 22 in that order) were further subjected to a cutting test under the following conditions (cutting conditions 3). The results are shown in Table 4. Further, with respect to each cutting tip, the structure of the TiC matrix was observed by a scanning electron microscope, and the average particle size was measured. The results are also shown in Table 4.

Cutting condition 3 Work material: FCD70 Cutting speed: 180 m / min Feed: 0.4 mm / rotation Depth of cut: 1 mm Chip model number: SNGN120408 Holder: FN11R-44A Cutting agent: APC-10 (10) Cutting time: 5 minutes

[0063] Table 4 flank wear width TiC average particle size Example No. (mm) (μm) Example 9 0.05 0.8 Example 10 0.07 1.2 Example 11 0.06 1.3 Embodiment Example 12 0.05 0.9 Example 13 0.08 0.7 Comparative Example 18 0.16 4.2 Comparative Example 19 0.14 3.5 Comparative Example 20 0.25 5.4 Comparative Example 21 0.21 4.8 Comparative Example 22 0.18 3.2

[0064]

As described above, the cutting tool according to the present invention is excellent in fracture resistance and wear resistance. The cutting tool according to the present invention can satisfactorily cut not only spheroidal graphite cast iron but also work materials such as gray cast iron and high hardness alloy steel.

The cutting tool according to the present invention is suitable for various cutting tips, drills and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C04B 35/80 C04B 35/80 C

Claims (9)

[Claims] 1. TiC, Al ₂ O ₃ , SiC whiskers and Zr
In a ceramic cutting tool composed of O ₂ , Al ₂ O ₃ is 5 to 30% by volume, ZrO ₂ is 1 to 12% by volume, SiC whiskers are 3 to 40% by volume, and the balance is substantially 2 μm in average particle size. It consists of the following TiC, and the SiC whiskers have an average diameter and an average length of 0.1 to 1 μm and 2 respectively.
A ceramic cutting tool having a thickness of 50 μm and 50% or more of the SiC whiskers having an α-type crystal structure or a β-type crystal structure. 2. The ceramic cutting tool according to claim 1, wherein the SiC whiskers have an average diameter and an average length of 0.2 to 0.8 μm and 10 to 40 μm, respectively. 3. The ceramic cutting tool according to claim 1, wherein 80% or more of the SiC whiskers have an α-type crystal structure, or 2θ = 3 in an x-ray diffraction pattern.
A ceramic cutting tool having a β-type crystal structure having a peak at 3.6 ° and substantially no peak at 2θ = 41.4 °. 4. The ceramic cutting tool according to claim 1, wherein the content of the SiC whiskers is 8 to 19% by volume. 5. The ceramic cutting tool according to claim 1, wherein the content of the SiC whiskers is 20 to 35% by volume. 6. The ceramic cutting tool according to claim 1, wherein the TiC has an average particle size of 1.5.
Ceramic cutting tool characterized by having a size of less than μm. 7. The ceramic cutting tool according to claim 1, wherein the TiC has an average particle size of 1.0.
Ceramic cutting tool characterized by having a size of less than μm. 8. (a) TiC powder having an average particle size of 1 μm or less,
(b) Al ₂ O ₃ powder having an average particle size of 1 μm or less, and (c) ZrO ₂
Powder, and (d) the average diameter and the average length are each 0.1 to
A raw material powder containing 1 μm and 2 to 50 μm, and 50% or more of SiC whiskers having an α-type crystal structure or a β-type crystal structure is used, and the temperature is 1500 to 1800 ° C. and 150 to 500 kg / cm ² 30 minutes to 10 minutes
A method for manufacturing a ceramic cutting tool, which comprises performing pressure sintering for a period of time. 9. The method of claim 8, wherein the Ti
A method for manufacturing a ceramic cutting tool, wherein the average particle diameter of C is 0.2 to 0.5 μm.