JP2013234093A - SiAlON-BASED PARTICLE, SINTERED BODY AND TOOL - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide SiAlON-based particles having excellent grinding resistance, a sintered body having excellent abrasion resistance and defect resistance, and a tool using the sintered body.SOLUTION: SiAlON-based particles contain at least either of α-phase type SiAlON and β-phase type SiAlON, and γ-phase type SiAlON, have the average particle diameter of ≥0.1 μm and ≤100 μm when being ultrasonically dispersed into an ethanol solvent, and contain, with respect to the total mass of silicon, aluminum, oxygen and nitrogen in the SiAlON-based particles, ≥18.68 to ≤59.33 mass% silicon, ≥0.96 to ≤38.72 mass% aluminum, ≥2.08 to ≤24.44 mass% oxygen, and ≥18.16 to ≤37.63 mass% nitrogen, wherein the peak intensity Iα of an X-ray diffraction line on (201) plane of the α-phase type SiAlON by an X-ray diffraction method, the peak intensity Iβ of the X-ray diffraction line on (101) plane of the β-phase type SiAlON by the X-ray diffraction method, and the peak intensity Iγ of the X-ray diffraction line on (400) plane of the γ-phase type SiAlON by the X-ray diffraction method are expressed by the following formula (I): 0.09≤(Iα+Iβ)/(Iα+Iβ+Iγ)≤0.88.

Description

  The present invention relates to SiAlON base particles, a sintered body, and a tool, and more specifically, SiAlON base particles including at least one of α-phase type SiAlON and β-phase type SiAlON and γ-phase type SiAlON, and the base particles. The present invention relates to a sintered body and a tool using the sintered body.

Since diamond particles and cubic boron nitride (hereinafter also referred to as cBN) particles have higher hardness than Al ₂ O ₃ particles and SiC particles, hard particles for grinding and cutting tools are used as hard particles instead of these particles. It is used as

  The required characteristics for hard particles vary depending on the type of work material and the processing method. For example, diamond powder is suitable for processing ceramics and non-ferrous metals. On the other hand, in iron-based metals such as steel and cast iron, carbon in diamond reacts with the work material at a high temperature, and therefore cBN powder having a lower affinity with iron group elements than diamond is used.

However, since cBN reacts with iron group metals such as Fe, Ni, and Co at high temperatures, development of hard particle raw materials that have higher hardness and better toughness than Al ₂ O ₃ particles and SiC particles is desired. It is rare.

  The hard particle material that replaces cBN is not only a material for cutting and cutting tools, but also in the fields of plastic working and friction stir welding represented by punches and dies, made of high-speed steel, cemented carbide It is expected to be used as a tool material in place of tools made of ceramics, ceramics, diamond sintered bodies, or cBN sintered bodies.

  SiAlON (hereinafter also referred to as sialon) has a structure in which aluminum and oxygen are dissolved in silicon nitride, and α-phase SiAlON (hereinafter also referred to as α-SiAlON) belonging to hexagonal system and β-phase SiAlON. There are two types of crystal forms (hereinafter also referred to as β-SiAlON). Since a sintered body using sialon has a characteristic of low reactivity with a workpiece, research as a cutting tool material has been advanced.

For example, Patent Document 1 (Japanese Patent Laid-Open No. 2002-121013) discloses that the chemical formula Si _(6-x) Al _x O _x N _(8-x) (0 _{) is obtained} by instantaneously pressurizing β-SiAlON with a shock wave. A method of synthesizing a high-pressure phase spinel sialon (hereinafter also referred to as γ-SiAlON) powder represented by <x ≦ 4.2) is disclosed.

  Since γ-SiAlON is a high-pressure phase of β-SiAlON, it can be inferred that it has a higher density and higher hardness than β-SiAlON powder, but its toughness is not sufficient and wear resistance is also high. Further improvements are required.

  Therefore, the present inventors conducted a grinding test of the γ-SiAlON powder and a cutting evaluation of a Ni-based heat-resistant alloy with a sintered body made of the powder, and compared with conventional α-SiAlON, β-SiAlON powder, and cBN powder. The comparison was carried out. Surprisingly, γ-SiAlON particles have better wear resistance than α-SiAlON and β-SiAlON under low load conditions (low stress conditions), but α-SiAlON under high load conditions (high stress conditions). And β-SiAlON were found to be inferior in wear resistance and fracture resistance. As a result of observing the damage state, it is confirmed that, under high load conditions, the damage of γ-SiAlON is larger than that of α-SiAlON and β-SiAlON, and crushing of γ-SiAlON particles and accumulation of chipping are confirmed. The γ-SiAlON disclosed in No. 1 is presumed to result in wear and fracture due to insufficient toughness.

  In Patent Document 2 (Japanese Patent Laid-Open No. 2011-256067), β-SiAlON is converted into γ-SiAlON by treatment with β-SiAlON and converted into γ-SiAlON, and β-SiAlON and the first compound (iron, cobalt, nickel, period) At least one element selected from the group consisting of Group 4a element, Group 5a element, and Group 6a element) and the second compound (Group 4a element, Group 5a element, and Group 6a element) At least one compound selected from the group consisting of at least one compound selected from the group consisting of carbon, nitrogen, and boron) and sintering. A sintered body is disclosed.

  The sintered body is prepared by individually preparing γ-SiAlON particles, β-SiAlON particles, a first compound, and a second compound, and sintering a powder obtained by mixing these. Patent Document 2 aims to improve the bonding force between SiAlON particles by using at least one of the first compound and the second compound. However, since the toughness of the main component γ-SiAlON particles itself is not sufficient, in cutting applications, etc., fractures and wear resistance of the sintered body starting from crushing and cracks generated in the γ-SiAlON particles due to the generation of high stress. There is a problem of causing variation in sex.

Japanese Patent Laid-Open No. 2002-121013 JP 2011-256067 A

  An object of the present invention is to provide SiAlON-based particles having excellent abrasion resistance, a sintered body having excellent wear resistance and fracture resistance, and a tool using the sintered body.

  The SiAlON-based particles of the present invention contain at least one of α-phase type SiAlON and β-phase type SiAlON and γ-phase type SiAlON, and have an average particle size of 0.1 μm or more and 100 μm or less when ultrasonically dispersed in an ethanol solvent. The silicon is 18.68% by mass to 59.33% by mass and the aluminum is 0.96% by mass to 38.72% by mass with respect to the total mass of silicon, aluminum, oxygen and nitrogen in the SiAlON group particles. % Of oxygen phase in the range of 2.08 mass% or more and 24.44 mass% or less and nitrogen in the range of 18.16 mass% or more and 37.63 mass% or less. ) Plane X-ray diffraction line peak intensity Iα, X-ray diffraction method β-phase type SiAlON (101) plane X-ray diffraction line peak intensity Iβ, and X-ray Peak intensity Iγ of X-ray diffraction line at (400) plane of γ-phase type SiAlON by folding method, represented by the following formula (I).

0.09 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.88 (I)
In the SiAlON group particles of the present invention, preferably, the SiAlON group particles are 34.71% by mass or more and 58.29% by mass or less of silicon with respect to the total mass of silicon, aluminum, oxygen, and nitrogen in the SiAlON group particles. 1.93 mass% or more and 23.83 mass% or less of aluminum, 2.65 mass% or more and 15.62 mass% or less of oxygen, and 25.84 mass% or more and 37.13 mass% or less of nitrogen, Iα, Iβ, and Iγ are represented by the relationship of the following formula (II).

0.13 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.82 (II)
In the SiAlON group particles of the present invention, preferably, the SiAlON group particles contain 45.02% by mass or more and 57.26% by mass or less of silicon with respect to the total mass of silicon, aluminum, oxygen, and nitrogen in the SiAlON group particles. Aluminum is contained in the range of 2.89% to 14.61% by mass, oxygen 2.84% to 10.2% by mass, and nitrogen 30.17% to 36.63% by mass, Iα, Iβ, and Iγ are represented by the following formula (III).

0.18 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.75 (III)
As a result of intensive studies in view of the above problems, the present inventors have found that the SiAlON-based particles include at least one of α-phase SiAlON and β-phase SiAlON and γ-phase SiAlON, and silicon in the SiAlON-based particles, It has been found that when the contents of aluminum, oxygen, and nitrogen and the relationship between Iα, Iβ, and Iγ satisfy the above ranges, they have excellent abrasion resistance. This is presumably because the SiAlON-based particles of the present invention have a high hardness and an excellent balance between hardness and toughness. It is conceivable that the reason why the SiAlON-based particles have high hardness is that the SiAlON-based particles include γ-phase SiAlON having higher density and hardness than α-phase SiAlON and β-phase SiAlON. The reason why the balance between the hardness and the toughness of the SiAlON-based particles is excellent is that the SiAlON-based particles, together with the γ-phase type SiAlON, are at least α-phase type SiAlON and β-phase type SiAlON having toughness superior to the γ-phase type SiAlON. It is conceivable to include either.

In the SiAlON group particles of the present invention, preferably, the SiAlON group particles further include a toughening component, and the toughening component is boron, carbon, magnesium, calcium, yttrium, iron, nickel, cobalt, Group 4a element of the periodic table , Group 5a element, Group 6a element, Si ₃ N ₄ , AlON, AlN, and Al ₂ O ₃ , and a toughening component by Iα, Iβ, Iγ, and X-ray diffraction The peak intensity Is (hkl) of the strongest diffraction line is represented by the following formula (IV).

0.01 ≦ Is (hkl) / (Iα + Iβ + Iγ) ≦ 0.3 (IV)
In the SiAlON-based particles of the present invention, Iα, Iβ, Iγ, and Is (hkl) are preferably represented by the following formula (V).

0.01 ≦ Is (hkl) / (Iα + Iβ + Iγ) ≦ 0.2 (V)
The toughening component exhibits the effect of toughening due to the presumed effect of applying the residual stress resulting from the difference in thermal expansion coefficient, Young's modulus, or solid solution after the synthesis of the SiAlON-based particles of the present invention. Therefore, the SiAlON-based particles containing the toughening component at a ratio where the value of Is (hkl) / (Iα + Iβ + Iγ) falls within the range of the above formula (IV) or formula (V) has an excellent balance between hardness and toughness. Excellent abrasion resistance.

  In the SiAlON-based particles of the present invention, the half width of the X-ray diffraction line on the (400) plane of the γ-phase type SiAlON is preferably 0.4 ° or more and 2.0 ° or less.

  The SiAlON base particles of the present invention in which the full width at half maximum of the X-ray diffraction line at the (400) plane of γ-phase type SiAlON is 0.4 ° or more and 2.0 ° or less are firmly bonded with fine primary particles. Since it becomes a sintered abrasive grain, it exhibits particularly high toughness and high abrasion resistance. When the half-value width is less than 0.4 °, the primary particles are too coarse, so that the primary particles have a weak holding force, and cleaving may occur, so that the abrasion resistance decreases. On the other hand, when the half width exceeds 2.0 °, the primary particles become fine particles, and the propagation resistance of cracks generated at the grain boundaries of the primary particles may be low, and the toughness may be reduced.

  The sintered body of the present invention contains 20% by volume or more and 95% by volume or less of the SiAlON base particles of the present invention.

  When the content of the SiAlON group particles in the sintered body is 20% by volume or more and 95% by volume or less, the chipping resistance and wear resistance of the sintered body are improved. This is considered because the effect of dispersion strengthening by SiAlON group particles is obtained.

  Preferably, in the sintered body of the present invention, the sintered body is composed of SiAlON-based particles and the balance, and the balance is aluminum, boron, silicon, iron, nickel, cobalt, magnesium, calcium, yttrium, and 4a of the periodic table. At least one element selected from the group consisting of Group elements, Group 5a elements and Group 6a elements, and at least one element selected from the group consisting of carbon, nitrogen, oxygen and boron It includes at least one selected from the group consisting of a compound and a solid solution of the compound.

  In the sintered body of the present invention, preferably, the balance includes at least one of AlN and BN.

  When the above-mentioned compound and the solid solution of the compound are contained in the remaining part of the sintered body, the fracture resistance and the wear resistance of the sintered body are improved. This is presumably because the above-mentioned compound and the solid solution of the compound increase the bonding force between the SiAlON group particles in the sintered body.

  The sintered body of the present invention is used for the tool of the present invention. A tool using the sintered body of the present invention as a material has excellent wear resistance and fracture resistance.

  ADVANTAGE OF THE INVENTION According to this invention, the SiAlON group particle | grains excellent in abrasion resistance, the sintered compact which has the outstanding abrasion resistance and fracture resistance, and the tool using this sintered compact can be provided.

[Embodiment 1]
In one embodiment of the present invention, the SiAlON-based particles include at least one of α-phase SiAlON and β-phase SiAlON, and γ-phase SiAlON.

(SiAlON base particles)
In this specification, “SiAlON-based particles” means particles containing at least one of α-phase SiAlON, β-phase SiAlON, and γ-phase SiAlON.

  SiAlON is a general term for a group of Si-Al-O-N compounds. SiAlON is classified according to crystal type into α phase type SiAlON, β phase type SiAlON, spinel type SiAlON (hereinafter also referred to as γ phase type SiAlON), and the like.

β-phase type SiAlON is a solid solution in which Al is substituted at the Si position of β-phase type Si ₃ N ₄ belonging to the hexagonal system and O is substituted at the N position in substitutional form. The general formula Si _(6-Z) Al _Z O _Z N _(8−Z) (0 <z ≦ 4.2).

  Since β-phase type SiAlON has low reactivity with the work material and high toughness, if β-phase type SiAlON is used as a raw material for the sintered body, a sintered body having excellent wear resistance and fracture resistance can be obtained. Can be obtained.

α-phase SiAlON is a hexagonal α-phase Si ₃ N ₄ in which Al is substituted in a substitutional form at the Si position and O is substituted at the N position, and a specific metal atom penetrates between crystal lattices. It is a solid solution that is a solid solution of the mold, and is represented by the general formula M _x Si _12-3x Al _3x O _x N _16-x . Here, M represents an element that dissolves in an interstitial type, such as Li, Ca, and Mg.

  Since α-phase SiAlON has low reactivity with the work material and high toughness, when α-phase SiAlON is used as a raw material for the sintered body, a sintered body having excellent wear resistance and fracture resistance can be obtained. Can be obtained.

γ-phase SiAlON has a crystal structure similar to that of spinel, which is a mineral belonging to a cubic system composed of magnesium aluminate (MgAl ₂ O ₄ ), and has a general formula of Si _(6-Z) Al _Z O _Z N _{( 8−Z)} (0 <z ≦ 4.2). The γ phase type SiAlON can be obtained, for example, by subjecting the low pressure phase β-SiAlON powder to static compression or impact compression treatment to cause the low pressure phase β-SiAlON to undergo phase transition to the high pressure phase γ phase type SiAlON.

  Since γ-phase type SiAlON is a high-pressure phase of β-phase type SiAlON, it has a higher density and hardness than β-phase type SiAlON, and when used as a sintered body raw material, a sintered body having excellent wear resistance is obtained. Can be obtained.

  The SiAlON base particles have an average particle size of 0.1 μm or more and 100 μm or less when ultrasonically dispersed in an ethanol solvent. Here, “the average particle size is 0.1 μm or more and 100 μm or less” means that 0.5 g of SiAlON base particles is put in 20 g of ethanol, and after pulverizing and dispersing for 1 minute with an ultrasonic vibration device, the laser The particle size distribution (D50) is 0% when the refractive index of ethanol is 1.36 and the refractive index of the measured powder is 2.2 with a particle size distribution measuring apparatus of formula (MT3300EX2 manufactured by Microtrac). It means 1 μm or more and less than 100 μm. The SiAlON-based particles of the present invention can maintain an average particle diameter of 0.1 μm or more and 100 μm or less even after ultrasonic dispersion treatment, and have excellent strength. A sintered body having wear resistance and fracture resistance can be obtained.

  When the average particle diameter of the SiAlON base particles is less than 0.1 μm, the surface area increases, so that an embrittlement layer due to oxidation is easily formed, and the toughness decreases. On the other hand, when the average particle size exceeds 100 μm, when a sintered body containing SiAlON base particles is used for cutting applications, scratches due to coarse particles, crushing due to particle strength reduction, and dropping off from the sintered body occur. . For this reason, the quality of the surface roughness of the workpiece is reduced. The average particle size is preferably 0.2 μm or more and 8 μm or less.

  SiAlON group particles are 18.68 mass% or more and 59.33 mass% or less of silicon, and 0.96 mass% or more and 38.33 mass% or less of silicon with respect to the total mass of silicon, aluminum, oxygen, and nitrogen in SiAlON group particles. 72 mass% or less, oxygen in the range of 2.08 mass% or more and 24.44 mass% or less, and nitrogen in the range of 18.16 mass% or more and 37.63 mass% or less, and the α phase type SiAlON in the SiAlON base particles The X-ray diffraction line peak intensity Iα at the (201) plane, the β-phase SiAlON peak intensity Iβ at the (101) plane by the X-ray diffraction method, and the γ by the X-ray diffraction method The peak intensity Iγ of the X-ray diffraction line at the (400) plane of the phase type SiAlON is represented by the following formula (I).

0.09 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.88 (I)
Here, the content of each element in the SiAlON group particles is a value measured using a high frequency inductively coupled plasma emission analysis method (ICP analysis), an inert gas melting infrared absorption method, and an inert gas melting thermal conductivity method. is there.

  When the value of (Iα + Iβ) / (Iα + Iβ + Iγ) is in the range represented by the formula (I), the balance of the contents of α-phase type SiAlON, β-phase type SiAlON, and γ-phase type SiAlON in the SiAlON-based particles is good, The abrasion resistance of the SiAlON base particles is improved.

The SiAlON-based particles can be produced, for example, by the following method.
At least one of α-phase type SiAlON and β-type SiAlON is prepared. When α-phase type SiAlON is used, a bead mill or a jet is used until the half-value width of the X-ray diffraction line on the (201) plane of α-phase type SiAlON by X-ray diffraction method is 0.35 ° or more and 2.0 ° or less. A fine structure is obtained by pulverization by mill treatment, introduction of strain, and the like to produce a low crystalline α-phase SiAlON. Similarly, when β-phase type SiAlON is used, the X-ray diffraction line on the (101) plane of β-phase type SiAlON by the X-ray diffraction method is fine until the half width of the X-ray diffraction line becomes 0.35 ° or more and 2.0 ° or less. An organization process is performed to produce a low crystalline β-phase SiAlON. The low crystalline α-phase type SiAlON and β-phase type SiAlON are processed by an impact compression method under the conditions of a pressure of 15 GPa or more and 50 GPa or less and a temperature of 1200 ° C. or more and 3000 ° C. or less to satisfy the condition of the above formula (I). SiAlON-based particles can be obtained. In addition, in the microstructuring process of α phase type SiAlON and β phase type SiAlON, when pulverized until the half width exceeds 2.0 °, the γ phase is oxidized due to the increase in the specific surface area of the SiAlON particles. The conversion rate to type SiAlON decreases. For this reason, it is difficult to obtain SiAlON-based particles that satisfy the condition of the above formula (I) even if the subsequent impact compression conditions (pressure, temperature, time) are adjusted.

  In place of the above-mentioned impact compression method, using a multi-anvil press or the like, by adjusting the synthesis time by a static pressure synthesis method under conditions of a pressure of 0.1 GPa or more and less than 20 GPa and a temperature of 1000 ° C. or more and 2000 ° C. or less, SiAlON base particles satisfying the condition of the formula (I) can be obtained.

  SiAlON group particles are 34.71 mass% or more and 58.29 mass% or less of silicon, and aluminum 1.93 mass% or more and 23.23 mass% or less with respect to the total mass of silicon, aluminum, oxygen, and nitrogen in SiAlON group particles. 83% by mass or less, oxygen in a range of 2.65% by mass to 15.62% by mass and nitrogen in a range of 25.84% by mass to 37.13% by mass, wherein Iα, Iβ, and Iγ are as follows: It is preferably represented by the relationship of formula (II).

0.13 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.82 (II)
SiAlON group particles are 45.02 mass% or more and 57.26 mass% or less of silicon, and aluminum is 2.89 mass% or more and 14.14 mass% or less with respect to the total mass of silicon, aluminum, oxygen, and nitrogen in SiAlON group particles. 61 mass% or less, oxygen is contained in the range of 2.84 mass% or more and 10.2 mass% or less, and nitrogen is 30.17 mass% or more and 36.63 mass% or less, and the Iα, Iβ, and Iγ are More preferably, it is represented by the formula (III).

0.18 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.75 (III)
As the SiAlON-based particles satisfying the conditions of the above formula (II) and the above formula (III), for example, at least one of α-phase type SiAlON and β-type SiAlON is prepared, and each of α-phase type SiAlON ( 201) the half width of the X-ray diffraction line on the (101) plane of the β-phase SiAlON by the X-ray diffraction method is 0.35 ° or more and 2.0 ° or less. Obtained by microstructuring until 35 ° or more and 2.0 ° or less, producing low crystalline α-phase type SiAlON and β-phase type SiAlON, and processing by impact compression method or static pressure synthesis method Can do.

  The SiAlON-based particles have an X-ray diffraction line half-width (hereinafter also referred to as FWHMγ) on the (400) plane of γ-phase SiAlON by X-ray diffraction method being 0.4 ° or more and 2.0 ° or less. Is preferred. In the present specification, “half width” means “full width at half maximum (FWHM)”. When the FWHMγ is 0.4 ° or more and 2.0 ° or less, fine primary particles are firmly bonded to sintered abrasive grains, so that particularly high toughness and high abrasion resistance are exhibited. If the half-value width is less than 0.4 °, the primary particles are too coarse, so that the primary particles have a weak holding force, and cleaves may occur. On the other hand, when the full width at half maximum exceeds 2.0 °, the primary particles become too fine, and the propagation resistance of cracks generated at the grain boundaries of the primary particles is low and the toughness is lowered. The range of FWHMγ is further preferably 0.4 ° or more and 1.5 ° or less.

  The SiAlON-based particles can include γ-phase SiAlON, β-phase SiAlON, Si—Al—O—N compounds other than α-phase SiAlON, and silicon nitride.

[Embodiment 2]
In one embodiment of the present invention, the SiAlON-based particles include at least one of α-phase SiAlON and β-phase SiAlON, γ-phase SiAlON, and further include a toughening component.

  As α-phase type SiAlON, β-phase type SiAlON, and γ-phase type SiAlON, the same ones as in the first embodiment can be used.

The toughening component is boron, carbon, magnesium, calcium, yttrium, iron, nickel, cobalt, Group 4a element, Group 5a element, Group 6a element of the periodic table, Si ₃ N ₄ , AlON, AlN and Al _It contains at least one selected from ₂ O ₃ . Here, “group 4a element of the periodic table” includes titanium, zirconium, and hafnium, and “group 5a element of the periodic table” includes vanadium, niobium, and tantum, “Group 6a elements” include chromium, molybdenum, and tungsten.

  The above elements and compounds exhibit a toughening effect due to the presumed effect of applying a residual stress due to thermal expansion difference, Young's modulus difference, or solid solution after synthesis of the SiAlON-based particles of the present invention. Therefore, SiAlON-based particles containing a toughening component can have excellent abrasion resistance.

  In the SiAlON-based particles containing the toughening component, the peak intensity Is (hkl) of the strongest diffraction line of the toughening component according to the Iα, Iβ, Iγ, and X-ray diffraction methods is represented by the following formula (IV). It is preferable.

0.01 ≦ Is (hkl) / (Iα + Iβ + Iγ) ≦ 0.3 (IV)
Here, the “peak intensity Is (hkl) of the strongest diffraction line of the toughening component” means the intensity of the diffraction line having the highest intensity ratio among the diffraction lines of the toughening component by the X-ray diffraction method. hkl), and Is (hkl) is preferably represented by the above formula (IV).

  When the value of Is (hkl) / (Iα + Iβ + Iγ) is in the range represented by the formula (IV), the contents of α-phase SiAlON, β-phase SiAlON, γ-phase SiAlON and toughening component in the SiAlON base particles And the SiAlON-based particles have good crush resistance.

  In the SiAlON-based particles containing the toughening component, the peak intensity Is (hkl) of the strongest diffraction line of the toughening component according to the Iα, Iβ, Iγ, and X-ray diffraction methods is represented by the following formula (V). More preferably.

0.01 ≦ Is (hkl) / (Iα + Iβ + Iγ) ≦ 0.2 (V)
SiAlON base particles containing a toughening component can be produced, for example, by the following method.

  At least one of α-phase SiAlON and β-type SiAlON is prepared, and the half-value width of the X-ray diffraction line on the (201) plane of α-phase SiAlON by X-ray diffraction method is 0.35 ° or more and 2.0 °, respectively. Thereafter, a fine structure treatment is performed until the half width of the X-ray diffraction line on the (101) plane of β-phase SiAlON by X-ray diffraction method is 0.35 ° or more and 2.0 ° or less. An α phase type SiAlON and a low crystalline β phase type SiAlON are prepared. 3 to 10 parts by mass of a toughening component is added to a total of 100 parts by mass of the obtained α phase type SiAlON and β phase type SiAlON, and ultrasonically dispersed in an organic solvent such as ethanol, or in a ball mill. The mixed slurry is dried with a drier or the like to obtain a mixed powder. The obtained mixed powder is subjected to an impact compression method under conditions of a pressure of 15 GPa to 50 GPa and a temperature of 1200 ° C. to 3000 ° C., or a static pressure synthesis method of a pressure of 0.1 GPa to less than 20 GPa and a temperature of 1000 ° C. to 2000 ° C. By treatment with SiAlON-based particles containing a toughening component can be obtained.

  The SiAlON-based particles can include γ-phase SiAlON, β-phase SiAlON, Si—Al—O—N compounds other than α-phase SiAlON, and silicon nitride.

[Embodiment 3]
In one embodiment of the present invention, the sintered body contains 20% by volume or more and 95% by volume or less of SiAlON-based particles.

  As the SiAlON-based particles, the same particles as in the first and second embodiments can be used.

  When the content of the SiAlON group particles in the sintered body is 20% by volume or more and 95% by volume or less, the fracture resistance and wear resistance of the sintered body are improved by dispersion strengthening with the SiAlON group particles. If the content of SiAlON group particles is less than 20% by volume, the effect of dispersion strengthening cannot be obtained. On the other hand, if the content of SiAlON group particles exceeds 95% by mass, it becomes difficult to sinter due to the characteristics of SiAlON group particles such as high toughness and chemical stability, so the characteristics of the sintered body deteriorate. The content of SiAlON group particles in the sintered body is more preferably 40% by volume or more and 80% by volume or less.

  The sintered body is composed of SiAlON-based particles and the balance, and the balance is aluminum, boron, silicon, iron, nickel, cobalt, magnesium, calcium, yttrium, and Group 4a element, Group 5a element and Group of the periodic table. At least one compound selected from the group consisting of Group 6a elements and at least one compound selected from the group consisting of carbon, nitrogen, oxygen and boron (hereinafter also referred to as a binder compound) ), And at least one selected from the group consisting of solid solutions of binder compounds. Since the binder compound and the solid solution of the binder compound have a high affinity with the SiAlON group particles, it is possible to obtain a sintered body excellent in fracture resistance and wear resistance when mixed and sintered with the SiAlON group particles. it can.

As the binder compound, for example, TiN, FeSi, Al ₂ O ₃ , TiO ₂ , TiS, TiB ₂ , TiCN, TiZrCN, Y ₂ O ₃ , CaO, TiSi, AlN, BN and the like can be used. Among these, it is preferable to use at least one of AlN and BN. Here, as AlN, both aluminum nitride (hAlN) belonging to the hexagonal system and aluminum nitride (cAlN) belonging to the cubic system can be used. As BN, any of boron nitride (hBN) belonging to the hexagonal system and boron nitride (cBN) belonging to the cubic system can be used.

The sintered body can be produced, for example, by the following method.
The SiAlON group particles and the binder compound are prepared so that the ratio of SiAlON group particles: binder compound is in the range of 20% by volume: 80% by volume to 95% by volume: 5% by volume. SiAlON group particles and a binder compound are dispersed and mixed using an ethanol solvent to obtain a mixed powder. The mixed powder can be sintered for 3 to 180 minutes using a girdle type ultra-high pressure press under conditions of a pressure of 0.1 GPa to 20 GPa and a temperature of 1000 ° C. to 2000 ° C. to obtain a sintered body.

[Embodiment 4]
In one embodiment of the present invention, the tool uses the sintered body of the present invention at least in part involved in cutting or plastic working. Examples of such tools include drills, end mills, milling or turning cutting edge exchangeable cutting tips, metal saws, gear cutting tools, reamers, tapping tips, friction stir welding tools, and the like.

  By using the sintered body of the present invention for a cutting edge of a tool or the like, even when cutting a difficult-to-cut material such as Inconel, it is possible to have excellent performance that it is difficult to cause a chipping and wear.

  The tool of the present invention is superior not only in cost performance but also in fracture resistance and wear resistance as compared with conventional α-SiAlON based ceramics, β-SiAlON based ceramics and cBN sintered body tools. It will be a thing.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.

<Samples 1 to 35>
(Preparation of raw material particles)
Prepare α-SiAlON (average particle size 5 μm) and β-SiAlON (average particle size 5 μm) as described in “filling amount (g)” in Table 1, crush and disperse and mix in a ball mill with carbide balls Thus, raw material particles were obtained.

(Measurement of raw material particles)
Measure the content of Si, Al, O, and N in raw material particles using high frequency inductively coupled plasma emission spectrometry (ICP analysis), inert gas melting infrared absorption method, inert gas melting thermal conductivity method did.

  The half widths at the (201) plane of α-phase SiAlON and the (101) plane of β-phase SiAlON were calculated by X-ray diffraction.

The results are shown in Table 1.
(Production of synthetic particles)
Next, 300 g of raw material particles were mixed with a heat sink and copper powder as a pressure medium, filled in a steel container, and processed at a pressure of 40 GPa and a temperature of 2000 ° C. by an impact compression method using an explosive explosion.

  The powder obtained by the impact compression treatment was pulverized by a ball mill. Next, the pulverized powder was treated with nitric acid to remove impurity components, and then classified and recovered with a water tank to obtain synthetic particles.

(Measurement of synthetic particles)
When the synthesized particles are analyzed by an X-ray diffraction method using Cu-Kα rays, the peak of an X-ray diffraction line corresponding to γ-SiAlON (γ-Si ₃ N of JCPDS074-3494 having a crystal structure equivalent to γ-SiAlON). ₄ ), X-ray diffraction line peak corresponding to α-SiAlON (using α-Si ₃ N ₄ of JCPDS041-0360), β-SiAlON (using β-Si ₃ N ₄ of JCPDS033-1160) X-ray diffraction line peaks corresponding to

  Next, the peak intensity Iγ of the X-ray diffraction line at the (400) plane of γ-SiAlON of the synthetic particle, the peak intensity Iα of the X-ray diffraction line at the (201) plane of α-SiAlON, (101 ) The peak intensity of the X-ray diffraction line on the surface was measured, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was calculated.

  The average particle size of the synthetic particles was measured using a laser type particle size distribution measuring device (MT3300EX2 manufactured by Microtrac).

  Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the synthetic particles are determined by high-frequency inductively coupled plasma atomic emission spectrometry (ICP analysis), and inert gas melting infrared. It was measured using an absorption method and an inert gas melting thermal conductivity method.

The results are shown in Table 1.
(Grinding test)
150 g of the prepared synthetic particles were rotated at 3000 rpm in an ethanol solvent containing Al ₂ O ₃ balls, and the time T (min) until the average particle diameter D50 of the synthetic particles became 1/2 was measured. . The greater the value of T, the better the abrasion resistance.

The results are shown in Table 1.
<Samples 36 to 38>
Samples 36 and 37 were subjected to the above grinding test using the following commercially available SiAlON particles as a conventional example. Sample 38 was subjected to the above grinding test using γ-SiAlON obtained by impact synthesis using β-SiAlON having good crystallinity as a starting material.

Sample 36: α-SiAlON (average particle size 5 μm)
Sample 37: β-SiAlON (average particle size 5 μm)
Sample 38: γ-SiAlON (average particle size 5 μm)
The results are shown in Table 1.

(Evaluation results)
The synthesized particles of Samples 2, 4, 5, 7 to 10, 12 to 14, 17 to 19, 21, 23 to 28, and 30 to 34 are based on the total mass of Si, Al, O, and N in the synthesized particles. , Si is 18.68 mass% or more and 59.33 mass% or less, Al is 0.96 mass% or more and 38.72 mass% or less, O is 2.08 mass% or more and 24.44 mass% or less, and N is 18. 16% by mass or more and 37.63% by mass or less, the average particle size is 0.2 μm or more and 100 μm or less, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} is 0.09 or more and 0.88 or less. The conditions for SiAlON-based particles according to the above were satisfied. In the grinding test, these synthetic particles were superior in abrasion resistance to the conventional samples 36 to 38.

  The synthetic particles of Sample 1 are 17.68% by mass of Si, 39.65% by mass of Al, 24.99% by mass of O, and N of 24.99% by mass with respect to the total mass of Si, Al, O, and N in the synthetic particles. Was 17.68% by mass, the average particle size was 5 μm, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was 0.96. The synthetic particles were inferior in abrasion resistance to synthetic particles such as Sample 2 that satisfy the conditions of the SiAlON-based particles according to the present invention.

  The synthetic particles of Samples 3, 6, 16, 20, 22, 29, and 35 had a value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} in the range of 0.91 to 0.96. The synthetic particles were inferior in abrasion resistance to synthetic particles such as Sample 2 that satisfy the conditions of the SiAlON-based particles according to the present invention.

  The synthetic particles of Sample 11 had an average particle size of 150 μm. The synthetic particles were inferior in abrasion resistance to synthetic particles such as Sample 2 that satisfy the conditions of the SiAlON-based particles according to the present invention.

  The synthetic particles of Sample 15 are composed of 59.85% by mass of Si, 0.48% by mass of Al, 1.80% by mass of O, N based on the total mass of Si, Al, O, and N in the synthetic particles. The average particle diameter was 5 μm, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was 0.04. The synthetic particles were inferior in abrasion resistance to synthetic particles such as Sample 2 that satisfy the conditions of the SiAlON-based particles according to the present invention.

<Samples 39 to 98>
(Preparation of raw material particles)
β-SiAlON particles (average particle size 1 μm) were prepared as described in “filling amount (g)” in Tables 2 and 3. In the β-SiAlON, as a toughening component, elements of the types described in “Additive elements” in Table 2 and Table 3 (B, C, Mg, Ca, Y, Fe, Ni, Co, Ti, Zr, Mo, W, Cr, Si ₃ N ₄ , AlON, AlN, Al ₂ O ₃ ) were added, and pulverized and dispersed and mixed in a ball mill with carbide balls to obtain raw material particles. In addition, as for the addition amount of the additive element, the ratio (mass%) of the mass (Mb) of the toughening component to the total mass (Mt) of the raw material particles is “Mb / Mt × 100 (mass%)” in Tables 2 and 3. It adjusted so that it might become the value of description.

(Measurement of raw material particles)
Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the raw material particles are determined by high frequency inductively coupled plasma atomic emission spectrometry (ICP analysis) and inert gas melting. It measured using the infrared absorption method and the inert gas melting thermal conductivity method.

The results are shown in Table 2 and Table 3.
(Production of synthetic particles)
Next, 300 g of raw material particles were mixed with a heat sink and copper powder as a pressure medium, filled in a steel container, and processed at a pressure of 40 GPa and a temperature of 2000 ° C. by an impact compression method using an explosive explosion.

  The powder obtained by the impact compression treatment was pulverized by a ball mill. Next, the pulverized powder was treated with nitric acid to remove impurity components, and then classified and recovered with a water tank to obtain synthetic particles.

(Measurement of synthetic particles)
When the synthetic particles are analyzed by the X-ray diffraction method using Cu-Kα ray, the peak of the X-ray diffraction line corresponding to γ-SiAlON, the peak of the X-ray diffraction line corresponding to α-SiAlON, and β-SiAlON X-ray diffraction line peaks were identified. Furthermore, the peak of the X-ray diffraction line corresponding to the toughening component was also identified.

  Next, the peak intensity Iγ of the X-ray diffraction line at the (400) plane of γ-SiAlON in the synthetic particles, the peak intensity Iα of the X-ray diffraction line at the (201) plane of α-SiAlON, ( The peak intensity of the X-ray diffraction line on the (101) plane was measured, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was calculated.

  Further, among the X-ray diffraction lines corresponding to the toughening component, the peak intensity Is (hkl) of the strongest diffraction line was measured, and the value of {Is (hkl) / (Iα + Iβ + Iγ)} was calculated.

  The average particle size of the synthetic particles was measured using a laser type particle size distribution measuring device (MT3300EX2 manufactured by Microtrac).

  Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the synthetic particles are determined by high-frequency inductively coupled plasma atomic emission spectrometry (ICP analysis), and inert gas melting infrared. It was measured using an absorption method and an inert gas melting thermal conductivity method.

The results are shown in Table 2 and Table 3.
(Grinding test)
150 g of the prepared synthetic particles were rotated at 3000 rpm in an ethanol solvent containing Al ₂ O ₃ balls, and the time T (min) until the average particle diameter D50 of the synthetic particles became 1/2 was measured. . The greater the value of T, the better the abrasion resistance.

  The results are shown in Table 2 and Table 3.

(Evaluation results)
The synthetic particles of Samples 40 to 56 include a toughening component, and Si is 29.68% by mass, Al is 28.51% by mass with respect to the total mass of Si, Al, O, and N in the synthetic particles. 18.39% by mass of O and 23.42% by mass of N, the average particle size is 5 μm, the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} is 0.85, and the value of Is (hkl) / (Iα + Iβ + Iγ) is 0.05. These synthetic particles were superior in abrasion resistance in the attrition test than Sample 39 which did not contain a toughening component.

  The synthetic particles of Sample 57 to Sample 69 include a toughening component, and the total mass of Si, Al, O, and N in the synthetic particles is 34.64% by mass of Si, 23.78% by mass of Al, It contained 17.08% by mass of O and 24.50% by mass of N, the average particle size was 5 μm, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was 0.75.

  The synthetic particles of Sample 70 to Sample 98 include a toughening component, and Si is 50.10% by mass, Al is 9.63% by mass with respect to the total mass of Si, Al, O, and N in the synthetic particles. It contained 8.71% by mass of O and 31.56% by mass of N, the average particle size was 5 μm, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was 0.70.

  The synthesized particles of Samples 58 to 60, Samples 62 to 64, and Samples 66 to 68 contained a toughening component, and the value of Is (hkl) / (Iα + Iβ + Iγ) was in the range of 0.01 to 0.30. In the grinding test, these synthetic particles showed equivalent or better grinding resistance than the sample 57 containing no toughening component.

  On the other hand, the synthetic particles of Samples 61, 65, and 69 contained a toughening component, and the value of Is (hkl) / (Iα + Iβ + Iγ) was 0.40. These synthetic particles were inferior in abrasion resistance in the attrition test as compared with the sample 57 containing no toughening component.

  Samples 71-73, Samples 75-77, Samples 79-81, Samples 83-85, Samples 87-89, Samples 91-93, Samples 95-97 contain toughening components and are Is (hkl) / (Iα + Iβ + Iγ) Was in the range of 0.01 to 0.30. In the grinding test, these synthetic particles showed equivalent or better abrasion resistance than the sample 70 containing no toughening component.

  On the other hand, Samples 74, 78, 82, 86, 90, 94, 98 contained a toughening component, and the value of Is (hkl) / (Iα + Iβ + Iγ) was 0.30 or more. These synthetic particles were inferior in abrasion resistance in the attrition test as compared to the sample 70 containing no toughening component.

<Samples 99 to 139>
(Preparation of raw material particles)
α-SiAlON (average particle size 2 μm) and β-SiAlON (average particle size 2 μm) were pulverized and dispersed and mixed by a ball mill using carbide balls to obtain raw material particles.

(Measurement of raw material particles)
The content (mass%) of each of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the raw material particles is determined by high frequency inductively coupled plasma atomic emission spectrometry (ICP analysis) and inert gas melting. It measured using the infrared absorption method and the inert gas melting thermal conductivity method.

  The full width at half maximum on the (201) plane of α-phase SiAlON and the (101) plane of β-phase SiAlON was calculated by X-ray diffraction.

The results are shown in Table 4 and Table 5.
(Production of synthetic particles)
Next, 300 g of the raw material particles are mixed with a heat sink and copper powder as a pressure medium, filled in a steel container, and subjected to the pressure (10 GPa to 50 GPa) shown in Tables 4 and 5 by an impact compression method by explosion of explosives. ) And temperature (1000 ° C. to 2000 ° C.).

  The powder obtained by the impact compression treatment was pulverized by a ball mill. Next, the pulverized powder was treated with nitric acid to remove impurity components, and then classified and recovered with a water tank to obtain synthetic particles.

(Measurement of synthetic particles)
When the synthesized particles are analyzed by X-ray diffraction using X-ray diffraction Cu-Kα ray, the peak of X-ray diffraction line corresponding to γ-SiAlON, the peak of X-ray diffraction line corresponding to α-SiAlON, β-SiAlON The peak of the X-ray diffraction line corresponding to is identified.

  Next, the peak intensity Iγ of the X-ray diffraction line at the (400) plane of γ-SiAlON in the synthetic particles, the peak intensity Iα of the X-ray diffraction line at the (201) plane of α-SiAlON, ( The peak intensity of the X-ray diffraction line on the (101) plane was measured, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was calculated.

  Furthermore, the half width of the X-ray diffraction line at the (400) plane of γ-SiAlON in the synthetic particles was calculated.

  The average particle size of the synthetic particles was measured using a laser type particle size distribution measuring device (MT3300EX2 manufactured by Microtrac).

  Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the synthetic particles are determined by high frequency inductively coupled plasma atomic emission spectrometry (ICP analysis), and inert gas melting infrared. It was measured using an absorption method and an inert gas melting thermal conductivity method.

The results are shown in Table 4 and Table 5.
(Grinding test)
150 g of the prepared synthetic particles were rotated at 3000 rpm in an ethanol solvent containing Al ₂ O ₃ balls, and the time T (min) until the average particle diameter D50 of the synthetic particles became 1/2 was measured. . The greater the value of T, the better the abrasion resistance.

  The results are shown in Table 4 and Table 5.

(Evaluation results)
Among the synthetic particles of Samples 99 to 139, when the synthetic particles having the same contents of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the synthetic particles are compared, The synthetic particles having a half-value width of the X-ray diffraction line on the (400) plane of γ-SiAlON of 0.4 ° to 2.0 ° are superior to other synthetic particles in terms of abrasion resistance. It was.

<Samples 140 to 185>
(Preparation of raw material particles)
α-SiAlON (average particle size 2 μm) and β-SiAlON (average particle size 2 μm) were prepared as described in “filling amount (g)” in Tables 6 and 7.

(Measurement of raw material particles)
Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the raw material particles are determined by high frequency inductively coupled plasma emission analysis (ICP analysis) and in an inert gas. Measurement was performed using a molten gas analysis method and a molten thermal conductivity method in an inert gas.

  The full width at half maximum on the (201) plane of α-phase SiAlON and the (101) plane of β-phase SiAlON was calculated by X-ray diffraction.

The results are shown in Table 6 and Table 7.
(Production of synthetic particles)
Next, 300 g of raw material particles were mixed with a heat sink and copper powder as a pressure medium, filled in a steel container, and processed at a pressure of 40 GPa and a temperature of 2000 ° C. by an impact compression method using an explosive explosion.

  The powder obtained by the impact compression treatment was pulverized by a ball mill. Next, the pulverized powder was treated with nitric acid to remove impurity components, and then classified and recovered with a water tank to obtain synthetic particles.

(Measurement of synthetic particles)
When the synthetic particles are analyzed by the X-ray diffraction method using Cu-Kα ray, the peak of the X-ray diffraction line corresponding to γ-SiAlON, the peak of the X-ray diffraction line corresponding to α-SiAlON, and β-SiAlON X-ray diffraction line peaks were identified.

  Next, the peak intensity Iγ of the X-ray diffraction line at the (400) plane of γ-SiAlON in the synthetic particles, the peak intensity Iα of the X-ray diffraction line at the (201) plane of α-SiAlON, ( The peak intensity of the X-ray diffraction line on the (101) plane was measured, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was calculated.

  Furthermore, the full width at half maximum of the X-ray diffraction line at the (400) plane of γ-SiAlON in the synthetic particles was calculated.

  The average particle size of the synthetic particles was measured using a laser type particle size distribution measuring device (MT3300EX2 manufactured by Microtrac).

  Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the synthetic particles are determined by high-frequency inductively coupled plasma atomic emission spectrometry (ICP analysis), and inert gas melting infrared. It was measured using an absorption method and an inert gas melting thermal conductivity method.

The results are shown in Table 6 and Table 7.
(Production of sintered body)
The obtained synthetic particles and a binder (TiN: FeNi: TiAl ₃ : Al ₂ O ₃ = mixed powder containing 70% by mass: 10% by mass: 15% by mass: 5% by mass) are shown in Table 6 and Dispersion mixing was performed using an ethanol solvent at a ratio described in “Content (volume%)” in Table 7 to obtain a mixed powder. The mixed powder is sintered using a girdle type ultra-high pressure press at a sintering pressure (0.1 to 20 GPa) and a sintering temperature (800 to 2200 ° C.) described in Tables 6 and 7 for 60 minutes and sintered. The body was made.

  Next, the sintered body is polished, the polished surface is observed using a scanning electron microscope (SEM), and wavelength dispersive X-ray analysis (EPMA: Electron Probe Micro-Analysis) attached thereto is used. Then, SiAlON and the binder component in the cross section of the composite sintered body were identified, and the percentage of the area ratio of SiAlON was calculated by image processing for the reflected electron image of a region including 100 or more SiAlON-based particles. As a result, the mixing ratio of the synthetic particles and the binder in the above mixed powder and the volume ratio of the synthetic particles and the binder constituting the finally obtained composite sintered body could be regarded as the same. In addition, the compound described in the column of “Type of binder of sintered body” in Table 6 and Table 7 indicates the type of compound contained in the balance in the sintered body.

(Cutting test)
A cutting tip provided with the obtained sintered body at a portion involved in cutting was produced. This chip shape is classified as CNGA120408 by ISO model number, and the cutting edge processing is a chamfer shape with an angle of -25 ° and a width of 0.15 mm, the cutting edge inclination angle, the side rake angle, the front clearance angle, the side clearance angle, The front cutting edge angle and the side cutting edge angle were respectively attached to the holder so as to be −5 °, −5 °, 5 °, 5 °, 5 °, and −5 °, and a cutting tool was produced.

  The tool life was evaluated by performing continuous cutting under the following cutting conditions using the cutting tool.

Work Material: Outside Diameter Processing of Inconel 718 Round Bar Work Material Hardness: HRC40
Cutting speed: V = 200 m / min
Cutting depth: d = 0.2mm
Feeding speed: f = 0.1mm / rev
Coolant: Emulsion diluted 20 times The tool life was evaluated by the cutting distance (km) until the maximum wear amount (VBmax) of the flank of the cutting tool reached 0.2 mm. When a defect occurred when the maximum wear amount (VBmax) was less than 0.2 mm, the evaluation was made based on the cutting distance until the defect occurred. In addition, it has shown that the abrasion resistance and fracture resistance of a cutting tool are excellent, so that cutting distance is long.

The results are shown in Table 6 and Table 7.
<Samples 186 to 188>
For Samples 186 to 188, the following sintered bodies were prepared, and a cutting test was performed under the same conditions as Samples 140 to 185.

Sample 186: α-SiAlON based ceramic sintered body.
Sample 187: β-SiAlON-based ceramic sintered body.

Sample 188: cBN (cubic boron nitride) based sintered body.
The results are shown in Table 6 and Table 7.

(Evaluation results)
Among the sintered bodies of samples 140 to 185, the sintered body having a synthetic particle content of 20 volume% or more and 95 volume% or less in the sintered body is more than the sintered bodies of samples 186 and 187, which are conventional examples. In the cutting test, the cutting distance was long, and the wear resistance and fracture resistance of the cutting tool were excellent.

  On the other hand, the sintered body of sample 180 has a content of synthetic particles in the sintered body of 10% by volume, and the cutting distance is shorter in the cutting test than the sintered body of samples 186 and 187, which are conventional examples. The wear resistance and fracture resistance of the cutting tool were inferior.

  For sample 174, the sintering process was performed only on the synthetic particles (the content of the synthetic particles in the sintered body was 100% by volume), but the sintered body could not be obtained.

  In the sample 146, since the sintering temperature was as low as 800 ° C., the diffusion and sintering between the SiAlON base particles and the binder did not proceed and the sintering could not be performed.

<Samples 189 to 234>
(Preparation of raw material particles)
α-SiAlON (average particle size 3 μm) and β-SiAlON (average particle size 3 μm) were prepared as described in “filling amount (g)” in Tables 8 and 9. Raw material particles were obtained by crushing, dispersing and mixing in a ball mill with carbide balls.

(Measurement of raw material particles)
Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the raw material particles are determined by high frequency inductively coupled plasma atomic emission spectrometry (ICP analysis), and inert gas melting. It measured using the infrared absorption method and the inert gas melting thermal conductivity method.

  The full width at half maximum on the (201) plane of α-phase SiAlON and the (101) plane of β-phase SiAlON was calculated by X-ray diffraction.

The results are shown in Table 8 and Table 9.
(Production of synthetic particles)
Next, 300 g of raw material particles were mixed with a heat sink and copper powder as a pressure medium, filled in a steel container, and processed at a pressure of 40 GPa and a temperature of 2000 ° C. by an impact compression method using an explosive explosion.

  The powder obtained by the impact compression treatment was pulverized by a ball mill. Next, the pulverized powder was treated with nitric acid to remove impurity components, and then classified and recovered with a water tank to obtain synthetic particles.

(Measurement of synthetic particles)
When the synthetic particles are analyzed by the X-ray diffraction method using Cu-Kα ray, the peak of the X-ray diffraction line corresponding to γ-SiAlON, the peak of the X-ray diffraction line corresponding to α-SiAlON, and β-SiAlON X-ray diffraction line peaks were identified.

  Next, the peak intensity Iγ of the X-ray diffraction line at the (400) plane of γ-SiAlON in the synthetic particles, the peak intensity Iα of the X-ray diffraction line at the (201) plane of α-SiAlON, ( The peak intensity of the X-ray diffraction line on the (101) plane was measured, and the value of {(Iα + Iβ) / (Iα + Iβ + Iγ)} was calculated.

  Further, among the X-ray diffraction lines corresponding to the toughening component, the peak intensity Is (hkl) of the strongest diffraction line was measured, and the value of {Is (hkl) / (Iα + Iβ + Iγ)} was calculated.

  Furthermore, the half width of the X-ray diffraction line at the (400) plane of γ-SiAlON in the synthetic particles was calculated.

  The average particle size of the synthetic particles was measured using a laser type particle size distribution measuring device (MT3300EX2 manufactured by Microtrac).

  Respective contents (mass%) of Si, Al, O, and N with respect to the total mass of Si, Al, O, and N in the synthetic particles are determined by high-frequency inductively coupled plasma atomic emission spectrometry (ICP analysis), and inert gas melting infrared. It was measured using an absorption method and an inert gas melting thermal conductivity method.

The results are shown in Table 8 and Table 9.
(Production of sintered body)
The obtained synthetic particles and various binders (1) to (12) below,
(1) A mixed powder containing TiN: TiAl ₃ : Al ₂ O ₃ : TiB ₂ = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with samples 189-209.
(2) A mixed powder containing TiCN: TiAl ₃ : Al ₂ O ₃ : TiB ₂ = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with samples 210-214.
(3) Mixed powder containing TiZrCN: TiAl ₃ : Al ₂ O ₃ : TiB ₂ = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with samples 215-219.
(4) Mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: Y ₂ O ₃ = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with samples 220-222.
(5) Mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: CaO = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with sample 223.
(6) Mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: FeSi = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with sample 224.
(7) Mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: TiSi = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with sample 225.
(8) A mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: AlN = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with sample 226.
(9) Mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: cAlN (cubic aluminum nitride) = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with sample 227.
(10) Mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: hBN (hexagonal boron nitride) = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with sample 228.
(11) A mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: cBN (cubic boron nitride) = 77% by mass: 15% by mass: 5% by mass: 3% by mass. Used with sample 229.
(12) A mixed powder containing TiCN: Al ₂ O ₃ : Ti ₂ AlN: AlN: cBN (cubic boron nitride) = 77% by mass: 12% by mass: 5% by mass: 3% by mass: 3% by mass. Used with samples 230-234.
Were dispersed and mixed using an ethanol solvent at a ratio described in “Content (volume%)” of Table 8 and Table 9 to obtain a mixed powder. The mixed powder was sintered for 120 minutes using a girdle type ultra-high pressure press under a pressure of 6 GPa and a temperature (800 to 2000 ° C.) described in Table 8 and Table 9 to prepare a sintered body.

  Next, the sintered body is polished, the polished surface is observed using a scanning electron microscope (SEM), and wavelength dispersive X-ray analysis (EPMA: Electron Probe Micro-Analysis) attached thereto is used. Then, SiAlON and the binder component in the cross section of the composite sintered body were identified, and the percentage of the area ratio of SiAlON was calculated by image processing for the reflected electron image of a region including 100 or more SiAlON-based particles. As a result, the mixing ratio of the synthetic particles and the binder in the above mixed powder and the volume ratio of the synthetic particles and the binder constituting the finally obtained composite sintered body could be regarded as the same. In addition, the compound described in the column of “Type of binder of sintered body” in Table 8 and Table 9 indicates the type of compound contained in the balance in the sintered body.

(Cutting test)
A cutting tip provided with the obtained sintered body at a portion involved in cutting was produced. This chip shape is classified as CNGA120408 by ISO model number, and the cutting edge processing is a chamfer shape with an angle of -25 ° and a width of 0.15 mm, the cutting edge inclination angle, the side rake angle, the front clearance angle, the side clearance angle, The front cutting edge angle and the side cutting edge angle were respectively attached to the holder so as to be −5 °, −5 °, 5 °, 5 °, 5 °, and −5 °, and a cutting tool was produced.

  The tool life was evaluated by performing continuous cutting under the following cutting conditions using the cutting tool.

Work Material: Outside Diameter Processing of Inconel 718 Round Bar Work Material Hardness: HRC40
Cutting speed: V = 200 m / min
Cutting depth: d = 0.2mm
Feeding speed: f = 0.1mm / rev
Coolant: Emulsion diluted 20 times The tool life was evaluated by the cutting distance (km) until the maximum wear amount (VBmax) of the flank of the cutting tool reached 0.2 mm. When a defect occurred when the maximum wear amount (VBmax) was less than 0.2 mm, the evaluation was made based on the cutting distance until the defect occurred. In addition, it has shown that the abrasion resistance and fracture resistance of a cutting tool are excellent, so that cutting distance is long.

  The results are shown in Table 8 and Table 9.

<Samples 235 to 237>
For samples 235 to 237, the following sintered bodies were prepared, and a cutting test was performed under the same conditions as samples 189 to 234.

Sample 235: α-SiAlON based ceramic sintered body.
Sample 236: β-SiAlON-based ceramic sintered body.

Sample 237: cBN (cubic boron nitride) -based sintered body.
The results are shown in Table 8 and Table 9.

(Evaluation results)
The sintered bodies of Samples 189 to 234 have a synthetic particle content of 80% by volume in the sintered bodies, and TiN, Al ₂ O ₃ , TiB ₂ , TiCN, TiZrCN, TiAl ₃ , and Ti ₂ AlN are used as binders. , Y ₂ O ₃ , CaO, FeSi, TiSi, AlN, cAlN, hBN, cBN, and the balance is TiN, Al ₂ O ₃ , TiB ₂ , TiCN, TiZrCN, Y ₂ O ₃ , CaO, FeSi , TiSi, AlN, cAlN, hBN, cBN. These sintered bodies were cut in the cutting test in comparison with the sintered bodies of the conventional samples 235 and 236 except for the sample 195 and the sample 223 in which the sintered body was not obtained even after the sintering process. The distance was long, and the wear resistance and fracture resistance of the cutting tool were excellent.

  Although the embodiments and examples of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims (10)

SiAlON-based particles containing at least one of α-phase SiAlON and β-phase SiAlON and γ-phase SiAlON,
The SiAlON base particles have an average particle size of 0.1 μm or more and 100 μm or less when ultrasonically dispersed in an ethanol solvent,
The SiAlON group particles are 18.68% by mass or more and 59.33% by mass or less of silicon and 0.96% by mass or more of aluminum with respect to the total mass of silicon, aluminum, oxygen, and nitrogen in the SiAlON group particles. 38.72% by mass or less, oxygen in the range of 2.08% by mass to 24.44% by mass, and nitrogen in the range of 18.16% by mass to 37.63% by mass,
X-ray diffraction line peak intensity Iα at the (201) plane of the α-phase type SiAlON by X-ray diffraction method, X-ray diffraction line peak intensity at the (101) plane of the β-phase type SiAlON by X-ray diffraction method SiAlON-based particles in which the peak intensity Iγ of the X-ray diffraction line on the (400) plane of the γ-phase SiAlON by Iβ and the X-ray diffraction method is represented by the following formula (I).
0.09 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.88 (I) The SiAlON group particles are 34.71% by mass or more and 58.29% by mass or less of silicon and 1.93% by mass or more of aluminum with respect to the total mass of silicon, aluminum, oxygen and nitrogen in the SiAlON group particles. 23.83% by mass or less, oxygen in a range of 2.65% by mass to 15.62% by mass, and nitrogen in a range of 25.84% by mass to 37.13% by mass,
2. The SiAlON-based particle according to claim 1, wherein Iα, Iβ, and Iγ are represented by a relationship of the following formula (II).
0.13 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.82 (II) The SiAlON group particles are 45.02% by mass or more and 57.26% by mass or less of silicon and 2.89% by mass or more of aluminum with respect to the total mass of silicon, aluminum, oxygen and nitrogen in the SiAlON group particles. 14.61% by mass or less, oxygen in a range of 2.84% by mass to 10.2% by mass, and nitrogen in a range of 30.17% by mass to 36.63% by mass,
The SiAlON group particle according to claim 1 or 2, wherein the Iα, the Iβ, and the Iγ are represented by the following formula (III).
0.18 ≦ (Iα + Iβ) / (Iα + Iβ + Iγ) ≦ 0.75 (III) The SiAlON-based particles further include a toughening component;
The toughening component includes boron, carbon, magnesium, calcium, yttrium, iron, nickel, cobalt, Group 4a element, Group 5a element, Group 6a element of the periodic table, Si ₃ N ₄ , AlON, AlN and Including at least one selected from Al ₂ O ₃ ,
The peak intensity Is (hkl) of the strongest diffraction line of the toughening component according to the Iα, the Iβ, the Iγ, and the X-ray diffraction method is represented by the following formula (IV): The SiAlON-based particles as described.
0.01 ≦ Is (hkl) / (Iα + Iβ + Iγ) ≦ 0.3 (IV) The SiAlON-based particle according to claim 4, wherein the Iα, the Iβ, the Iγ, and the Is (hkl) are represented by the following formula (V).
0.01 ≦ Is (hkl) / (Iα + Iβ + Iγ) ≦ 0.2 (V)   The half width of the X-ray diffraction line at the (400) plane of the γ-phase SiAlON by X-ray diffraction method is 0.4 ° or more and 2.0 ° or less. SiAlON based particles.   The sintered compact containing 20 volume% or more and 95 volume% or less of SiAlON base particles in any one of Claims 1-6. The sintered body consists of the SiAlON base particles and the balance,
The balance is at least one selected from the group consisting of aluminum, boron, silicon, iron, nickel, cobalt, magnesium, calcium, yttrium, and Group 4a, 5a and 6a elements of the Periodic Table Including at least one compound selected from the group consisting of an element and at least one element selected from the group consisting of carbon, nitrogen, oxygen and boron, and a solid solution of the compound,
The sintered body according to claim 7.   The sintered body according to claim 8, wherein the remaining portion includes at least one of AlN and BN.   The tool using the sintered compact in any one of Claims 7-9.