EP4357474A1 - Hartmetall - Google Patents

Hartmetall Download PDF

Info

Publication number
EP4357474A1
EP4357474A1 EP22935160.6A EP22935160A EP4357474A1 EP 4357474 A1 EP4357474 A1 EP 4357474A1 EP 22935160 A EP22935160 A EP 22935160A EP 4357474 A1 EP4357474 A1 EP 4357474A1
Authority
EP
European Patent Office
Prior art keywords
mass
phases
particle size
less
cemented carbide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP22935160.6A
Other languages
English (en)
French (fr)
Inventor
Tomoyuki Ishida
Yuki Tanaka
Kazuhiro Hirose
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Electric Hardmetal Corp
Original Assignee
Sumitomo Electric Hardmetal Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Electric Hardmetal Corp filed Critical Sumitomo Electric Hardmetal Corp
Publication of EP4357474A1 publication Critical patent/EP4357474A1/de
Pending legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides
    • C22C29/02—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides
    • C22C29/06—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds
    • C22C29/08—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides based on carbides or carbonitrides based on carbides, but not containing other metal compounds based on tungsten carbide
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F2005/001—Cutting tools, earth boring or grinding tool other than table ware

Definitions

  • the present disclosure relates to a cemented carbide.
  • Cemented carbides comprising hard phases of tungsten carbide (WC) and binder phases of cobalt (Co) have been used as materials for cutting tools conventionally (PTL 1 to PTL 4).
  • a cemented carbide of the present disclosure is a cemented carbide composed of hard phases and binder phases
  • Fig. 1 is a figure substituted for a photograph and showing an image obtained by subjecting an image of a cemented carbide of the present embodiment photographed through a scanning electron microscope to binarization processing.
  • a cutting tool having a long tool life even in intermittent processing of titanium-based hard-to-cut materials can be provided.
  • a cutting tool having a long tool life even in intermittent processing of titanium-based hard-to-cut materials can be provided.
  • a to B means the upper limit and the lower limit of the range (namely, A or more and B or less). If a unit is not described on the right of A, but described on the right of only B, the units of A and B are the same.
  • a compound or the like is represented by a chemical formula in which the atomic ratio is not particularly limited herein, all the conventionally well-known atomic ratios are included therein, and the atomic ratio should not be necessarily limited to only the atomic ratio in the stoichiometric range. For example, if a compound is described as "WC", all the conventionally well-known atomic ratios are included in the ratio between the numbers of atoms constituting WC.
  • One embodiment of the present disclosure (hereinafter also described as the "present embodiment") is a cemented carbide composed of hard phases and binder phases,
  • a cutting tool having a long tool life even in intermittent processing of titanium-based hard-to-cut materials can be provided. It is conjectured that the reason is as follows.
  • the hard phases and the binder phases are fine, and the hard phases and the binder phases are uniformly dispersed, so that the cemented carbide can have both excellent welding resistance and excellent breakage resistance. According to the cemented carbide of the present disclosure, a cutting tool having a long tool life even in intermittent processing of titanium-based hard-to-cut materials can therefore be provided.
  • the cemented carbide of the present embodiment is composed of the hard phases and the binder phases. That is, the total content of the hard phases and binder phases of the cemented carbide is 100% by mass.
  • the expression "the cemented carbide is composed of the hard phases and the binder phases" used herein means that as long as the effect of the present disclosure is exhibited, the cemented carbide can contain inevitable impurities besides the hard phases and the binder phases. Examples of the inevitable impurities include iron, molybdenum, and sulfur.
  • the content of the inevitable impurity in the cemented carbide (the total of the contents of two or more impurities in the case wherein the impurities are two or more) is preferably 0% by mass or more and less than 0.1% by mass.
  • the content of the inevitable impurities in the cemented carbide is measured by ICP (inductively coupled plasma) emission spectrometry (measuring apparatus: SHIMADZU CORPORATION "ICPS-8100" (TM)).
  • the lower limit of the content of the hard phases in the cemented carbide of the present embodiment be 84% by mass or more, 85% by mass or more, or 86% by mass or more. It is preferable that the upper limit of the content of the hard phases in the cemented carbide of the present embodiment be 92% by mass or less, 91% by mass or less, or 90% by mass or less. It is preferable that the content of the hard phases in the cemented carbide of the present embodiment be 84% by mass or more and 92% by mass or less, 85% by mass or more and 91% by mass or less, or 86% by mass or more and 90% by mass or less.
  • the lower limit of the content of the binder phases in the cemented carbide of the present embodiment be 8% by mass or more, 9% by mass or more, or 10% by mass or more. It is preferable that the upper limit of the content of the binder phase in the cemented carbide of the present embodiment be 16% by mass or less, 15% by mass or less, or 14% by mass or less. It is preferable that the content of the binder phases in the cemented carbide of the present embodiment be 8% by mass or more and 16% by mass or less, 9% by mass or more and 15% by mass or less, or 10% by mass or more and 14% by mass or less.
  • the cemented carbide of the present embodiment preferably comprises the hard phases at 84% by mass or more and 92% by mass or less and the binder phases at 8% by mass or more and 16% by mass or less.
  • the cemented carbide of the present embodiment preferably comprises the hard phases at 85% by mass or more and 91% by mass or less and the binder phases at 9% by mass or more and 15% by mass or less.
  • the cemented carbide of the present embodiment preferably comprises the hard phases at 86% by mass or more and 90% by mass or less and the binder phases at 10% by mass or more and 14% by mass or less.
  • the contents of the hard phases and the binder phases in the cemented carbide are measured by ICP emission spectrometry (measuring apparatus: SHIMADZU CORPORATION "ICPS-8100" (TM)).
  • the hard phases of the present embodiment contains tungsten carbide as a main ingredient.
  • the expression "containing tungsten carbide as a main ingredient” means that as long as the effect of the present disclosure is exhibited, the hard phases can contain a component other than tungsten carbide. If the hard phases contain a component other than tungsten carbide, the hard phases may contain tungsten carbide at 80% by mass or more. The hard phases may contain tungsten carbide at 85% by mass or more, 90% by mass or more, or 95% by mass or more.
  • the tungsten (W) content measured by ICP emission spectrometry is converted into the tungsten carbide (WC) content to determine the content of tungsten carbide in the hard phases.
  • the above-mentioned hard phases can contain a carbide, a nitride, a carbonitride, and an oxide of at least one element selected from the group consisting of Ti, Cr, V, Mo, Ta, Nb, and Zr; an inevitable impurity element mixed in the process for producing WC; a very small amount of an impurity element; and the like besides tungsten carbide.
  • these impurity elements include molybdenum (Mo) and chromium (Cr). It is preferable that the content of the impurity element (total content two or more impurity elements in the case of the two or more impurity elements) in the hard phases be less than 0.1% by mass.
  • the content of the impurity element in the hard phases is measured by ICP emission spectrometry (measuring apparatus: "ICPS-8100" (TM), manufactured by SHIMADZU CORPORATION).
  • ICP emission spectrometry measuring apparatus: "ICPS-8100" (TM), manufactured by SHIMADZU CORPORATION.
  • Subjecting a section of the cemented carbide to elemental mapping with an energy dispersive X-ray spectrometer (EDS) enables determining that the hard phases contain a carbide, a nitride, a carbonitride, and an oxide of at least one element selected from the group consisting of Ti, Cr, V, Mo, Ta, Nb, and Zr; an inevitable impurity element mixed in the process for producing WC; a very small amount of an impurity element; and the like.
  • the ratio D10/D90 of D10 being the area-based 10% cumulative particle size to D90 being the area-based 90% cumulative particle size is 0.30 or more.
  • the hard phases can be uniformly dispersed in the cemented carbide thereby.
  • the lower limit of D10/D90 is preferably 0.31 or more and more preferably 0.32 or more.
  • the upper limit of D10/D90 is preferably 0.50 or less, more preferably 0.45 or less, and further preferably 0.40 or less.
  • D10/D90 is preferably 0.31 or more and 0.50 or less, more preferably 0.31 or more and 0.45 or less, and further preferably 0.32 to be more and 0.40 or less.
  • D10/D90 is measured in a procedure comprising the following (A1) to (E1).
  • the hard phases can be discriminated from the binder phases based on the shade of color in the images subjected the binarization processing. For example, in the images subjected to the binarization processing, the hard phases are shown as black regions, and the binder phases are shown as white regions.
  • Fig. 1 shows an image obtained by subjecting one of the above-mentioned reflected electron images to binarization processing by the above-mentioned image analysis software (ImageJ).
  • the average particle size of the above-mentioned hard phases is 0.30 ⁇ m or more and 0.60 ⁇ m or less.
  • the hard phases can be micronized in the cemented carbide as a whole thereby.
  • the lower limit of the average particle size of the above-mentioned hard phases is preferably 0.35 ⁇ m or more and more preferably 0.40 ⁇ m or more.
  • the upper limit of the average particle size of the above-mentioned hard phase is preferably 0.55 ⁇ m or less and more preferably 0.50 ⁇ m or less.
  • the average particle size of the above-mentioned hard phases is preferably 0.35 ⁇ m or more and 0.55 ⁇ m or less, and further preferably 0.40 ⁇ m or more and 0.50 ⁇ m or less.
  • the average particle size of the above-mentioned hard phases is measured in a procedure comprising the following (A2) to (B2).
  • the binder phases of the present embodiment contain cobalt as a main ingredient.
  • the expression "containing cobalt as a main ingredient” means that the cobalt content in the binder phases is 80% by mass or more and 100% by mass or less.
  • the cobalt content in the binder phases is determined by ICP analysis.
  • the above-mentioned binder phases can contain iron (Fe), nickel (Ni), and a dissolved substance in the alloy (chromium (Cr), tungsten (W), vanadium (V), or the like) besides cobalt.
  • the binder phases can comprise cobalt and at least one selected from the group consisting of iron, nickel, chromium, tungsten and vanadium.
  • the binder phases can comprise cobalt; at least one selected from the group consisting of iron, nickel, chromium, tungsten, and vanadium; and inevitable impurities. Examples of the inevitable impurities include manganese (Mn), magnesium (Mg), calcium (Ca), molybdenum (Mo), sulfur (S), titanium (Ti), and aluminum (Al).
  • the binder phases contain iron (Fe); nickel (Ni); a dissolved substance in the alloy (chromium (Cr), tungsten (W), vanadium (V), or the like); and inevitable impurities.
  • EDS energy dispersive X-ray spectroscope
  • the ratio D10/D90 of D10 being the area-based 10% cumulative particle size to D90 being the area-based 90% cumulative particle size is 0.23 or more.
  • the binder phases can therefore be uniformly dispersed in the cemented carbide.
  • D10/D90 is preferably 0.24 or more and more preferably 0.25 or more.
  • D10/D90 is preferably 0.5 or less, more preferably 0.45 or less, and further preferably 0.4 or less.
  • D10/D90 is preferably 0.23 or more and 0.5 or less, more preferably 0.24 or more and 0.45 or less, and further preferably 0.25 or more and 0.4 or less.
  • D10/D90 is measured in a procedure comprising the following (A3) to (C3).
  • the average particle size of the above-mentioned binder phases is 0.25 ⁇ m or more and 0.50 ⁇ m or less.
  • the binder phases can therefore be micronized in the cemented carbide as a whole.
  • the average particle size of the above-mentioned binder phases is preferably 0.23 ⁇ m or more and more preferably 0.25 ⁇ m or more.
  • the average particle size of the above-mentioned binder phases is preferably 0.47 ⁇ m or less and more preferably 0.45 ⁇ m or less.
  • the average particle size of the above-mentioned binder phases is preferably 0.23 ⁇ m or more and 0.47 ⁇ m or less and more preferably 0.25 ⁇ m or more and 0.45 ⁇ m or less.
  • the average particle size of the above-mentioned binder phases is measured in a procedure comprising the following (A4) to (B4).
  • the total of the chromium content and the vanadium content is preferably 0.6% by mass or more and 2.1% by mass or less.
  • the ratio of the chromium content to the vanadium content may be any ratio.
  • the total of the chromium content and the vanadium content is more preferably 0.8% by mass or more and 1.9% by mass or less and further preferably 1.0% by mass or more and 1.7% by mass or less.
  • the chromium content in the cemented carbide of the present embodiment is preferably 0.4% by mass or more and 1.5% by mass or less. Chromium has the action of suppressing the grain growth of tungsten carbide particles. If the chromium content is in the range, the generation of coarse particles can be effectively suppressed, and the welding resistance and the breakage resistance of the cemented carbide can be further improved.
  • the chromium content is preferably 0.4% by mass or more, more preferably 0.5% by mass or more, and further preferably 0.6% by mass or more.
  • the chromium content is preferable 1.5% by mass or less, more preferably 1.4% by mass or less, and further preferably 1.3% by mass or less.
  • the chromium content is more preferably 0.5% by mass or more and 1.4% by mass or less and further preferably 0.6% by mass or more and 1.3% by mass or less.
  • the above-mentioned chromium can exist as solid solution in the binder phases.
  • the above-mentioned chromium is deposited as Cr 3 C 2 and can exist as the hard phases.
  • the above-mentioned chromium preferably exists as solid solution in the binder phases.
  • the chromium content in the cemented carbide is measured by ICP emission spectrometry.
  • the vanadium content is preferably 0% by mass or more and 0.6% by mass or less.
  • the vanadium has the action of suppressing the grain growth of tungsten carbide particles. If the vanadium content is in the range, the generation of coarse particles can be effectively suppressed, and the welding resistance and breakage resistance of the cemented carbide can be further improved.
  • the vanadium content is preferably 0.1% by mass or more and more preferably 0.2% by mass or more.
  • the vanadium content is preferably 0.55% by mass or less and more preferably 0.5% by mass or less.
  • the vanadium content is more preferably 0.1% by mass or more and 0.55% by mass or less and further preferably 0.2% by mass or more and 0.5% by mass or less.
  • the above-mentioned vanadium can exist as solid solution in the binder phases.
  • the above-mentioned vanadium is deposited as VC, and can exist as the hard phases.
  • the above-mentioned vanadium preferably exists as solid solution in the binder phases.
  • the content of vanadium in the cemented carbide is measured by ICP emission spectrometry.
  • a rectangular measurement visual field of 42.3 ⁇ m ⁇ 29.6 ⁇ m set in an image obtained by subjecting a section of the cemented carbide of the present disclosure to elemental mapping with an energy dispersive X-ray analyzer that the total number of first vanadium-containing particles and first chromium-containing particles is two or less, the particle size of the first vanadium-containing particles be 1 ⁇ m or more, and the particle size of the first chromium-containing particles be 1 ⁇ m or more.
  • the first vanadium-containing particles exist as the hard phases in the cemented carbide.
  • the first vanadium-containing particles mainly comprise vanadium and carbon, and can further contain impurities.
  • the impurities include W, Ti, Mo, Ta, Nb, Cr, N, and O.
  • the content of the impurities in the first vanadium-containing particles can be 30% by mass or less.
  • the content of the impurities is measured by ICP emission spectrometry.
  • the first chromium-containing particles exist as the hard phases in the cemented carbide.
  • the first chromium-containing particles mainly comprise chromium and carbon, and can further contain impurities.
  • the impurities include W, Ti, Mo, Ta, Nb, V, N, and O.
  • the content of the impurities in the first chromium-containing particles can be 30% by mass or less.
  • the content of the impurities is measured by ICP emission spectrometry.
  • the total number of first vanadium-containing particles and first chromium-containing particles be two or less. It is because the breakage resistance of the cemented carbide tends to decrease in the case where many first chromium-containing particles or many first vanadium-containing particles exist in the cemented carbide.
  • the total particle number of the first vanadium-containing particles and the first chromium-containing particles be one or less, and it is further preferable that the total number be zero, namely that the first vanadium-containing particles or the first chromium-containing particles does not exist.
  • the number of the first vanadium-containing particles and the number of the first chromium-containing particles is measured in the following procedure. That is, an observed image at a magnification of 3000 times is obtained using an electron microscope for any section of the cemented carbide.
  • the number of the first vanadium-containing particles and the amount of the first chromium-containing particles can then be counted to obtain the number of the first chromium-containing particles and the number of the first vanadium-containing particles.
  • the use of hard particle powder having a small particle size as a raw material and the mixing of chromium particle powder and vanadium particle powder besides hard particle powder and cobalt particle powder in the mixing step described below are devised. Since merely the use of hard particle powder having a small particle size as a raw material and merely the mixing of chromium particle powder and vanadium particle powder did not enable fully reducing spaces among the hard phases in the cemented carbide, the binder phases however tended to easily become coarse grains.
  • the binder phases contained in the cemented carbide may have been difficultly dispersed.
  • the present inventors have earnestly examined manufacturing conditions for obtaining cemented carbide of the present embodiment and consequently and newly found the optimal manufacturing conditions. Hereinafter, details about the method for manufacturing the cemented carbide of the present embodiment will be described.
  • the cemented carbide of the present embodiment can be typically manufactured by performing a step of preparing raw material powders, a mixing step, a molding step, a sintering step, and a cooling step in the order.
  • a step of preparing raw material powders a mixing step, a molding step, a sintering step, and a cooling step in the order.
  • the raw material powders of materials constituting the cemented carbide are prepared.
  • the raw material powders include tungsten carbide powder that is a raw material of the hard phases, cobalt (Co) powder that is a raw material of the binder phases, and chromium carbide (Cr 3 C 2 ) powder and vanadium carbide (VC) powder as a grain growth suppressant.
  • the grain growth suppressant can reduce the particle size of the hard phases constituted of the ultraparticulate tungsten carbide particles.
  • Commercial tungsten carbide powder, cobalt powder, chromium carbide powder, and vanadium carbide powder are available.
  • particulate WC powder (average particle size: 0.5 ⁇ m or more and 1.0 ⁇ m or less) and ultraparticulate WC powder (average particle size: 0.2 ⁇ m or more and 0.4 ⁇ m or less) are prepared.
  • the hard phases in the cemented carbide can therefore be formed into particulates as a whole. Since ultraparticulate tungsten carbide particles fills spaces among particulate tungsten carbide particles, the mean free path of cobalt can be decreased, and the particle size of the binder phases can therefore be reduced as a whole.
  • the present inventors have earnestly examined and consequently and newly found that the preparation of the two WC powders as described above enables forming the hard phases in the cemented carbide into particulates as a whole and reducing the particle sizes of the binder phases as a whole.
  • the average particle sizes of the raw material powders used herein mean average particle sizes measured by the FSSS (Fisher Sub-Sieve Sizer) method. The average particle sizes are measured with a "Sub-Sieve Sizer model 95" (TM), manufactured by Fisher Scientific K.K. The particle sizes of WC particles contained in the WC powders is measured with a particle size distribution measuring apparatus (trade name: MT3300EX) manufactured by MicrotracBEL Corp.
  • the average particle size of the cobalt powder can be 0.5 ⁇ m or more and 1.5 ⁇ m or less.
  • the average particle size of the chromium carbide powder can be 0.7 ⁇ m or more and 3.5 ⁇ m or less.
  • the average particle size of the vanadium carbide powder can be 0.1 ⁇ m or more and 1.2 ⁇ m or less. These average particle sizes are measured with a "Sub-Sieve Sizer model 95" (TM), manufactured by Fisher Scientific K.K.
  • the raw material powders prepared in the preparation step are mixed.
  • Mixed powder in which the raw material powders are mixed is obtained by the mixing step.
  • the blended amounts of the raw material powders in the mixed powder are suitably adjusted in view of the contents of the components such as the hard phases and the binder phases of the cemented carbide.
  • the blended amount of the particulate WC powder in the mixed powder can be 50.0% by mass or more and 71.0% by mass or less.
  • the blended amount of the ultraparticulate WC powder in the mixed powder can be 10% by mass or more and less than 29% by mass.
  • the blended amount of the cobalt powder in the mixed powder can be 6% by mass or more and 16% by mass or less.
  • the blended amount of the cobalt powder in the mixed powder is preferably more than 8% by mass and 16% by mass or less.
  • the blended amount of the chromium carbide powder in the mixed powder can be 0.4% by mass or more and 1.5% by mass or less.
  • the blended amount of the vanadium carbide powder in the mixed powder can be 0% by mass or more and 0.7% by mass or less.
  • the blended amount of the vanadium carbide powder in the mixed powder is preferably 0% by mass or more and 0.6% by mass or less.
  • the total of the blended amount of the chromium carbide powder in the mixed powder and the blended amount of the vanadium carbide powder in the mixed powder is preferably 0.6% by mass or more and 2.1% by mass or less.
  • a mixing method in which pulverization is controlled is used for maintaining the particles having different particle sizes (particulate tungsten carbide particles and ultraparticulate tungsten carbide particles) as they are.
  • a ball mill, an attritor, a Karman mixer, or the like is used.
  • a media-free mixer such as a Karman mixer
  • the pulverization of WC particles in the WC powders is easily suppressed.
  • the mixing time can be suitably adjusted depending on the mixed method. In the case of strong pulverization, the advantage of the above-mentioned composition is scarcely exhibited.
  • Cobalt is highly expansible, and becomes thin plate-like in the mixing step. In order to maintain the shapes of the above-mentioned particulate cobalt, it is desirable to feed cobalt after an elapse of at least half of the mixing time.
  • the mixed powder may be granulated as necessary.
  • the granulation of the mixed powder facilitates filling a die or a metal mold with the mixed powder during the molding step described below.
  • a well-known granulation method is applicable to the granulation, and for example, a commercial granulator such as a spray dryer is usable.
  • the mixed powder obtained in the mixing step is molded into a predetermined shape to obtain a compact.
  • a common method and common conditions only have to be adopted, and may be any method and any conditions.
  • the predetermined shape include the shape of a cutting tool (for example, the shape of a small-diameter drill).
  • the compact obtained by the molding step is sintered to obtain a sintered material.
  • the sintering temperature is 1400°C or more.
  • the flowing of the binder phases is promoted thereby, the rearrangement of the hard particles is also promoted, and the binder phases can therefore be uniformly dispersed in the cemented carbide.
  • the sintering temperature is less than 1400°C, the binder phases tend to be scarcely uniformly dispersed.
  • the present inventors have earnestly examined and consequently and newly found that the binder phases are uniformly dispersed in the cemented carbide by performing the sintering step at the sintering temperature as described above.
  • the sintering temperature is preferably 1500°C or less. If the sintering temperature exceeds 1500°C, the grains of the hard phases tend to grow easily.
  • the sintering time can be 0.5 hours or more and 2 hours or less after the heating and holding.
  • the cooling step the above-mentioned sintered material is cooled.
  • the cooling step is performed at a temperature decreasing rate of 5°C/minute or more. Since the amounts of Cr and V dissolved in the binder phases can be highly maintained thereby, the deposition of Cr and V can be suppressed thereby.
  • the expression "the temperature decreasing rate is 5°C/minute” means that the temperature decreases at a rate of 5°C per minute.
  • the present inventors have earnestly examined and consequently and newly found that the deposition of Cr and V can be suppressed by performing the cooling step at the temperature decreasing rate as described above.
  • the temperature decreasing rate is preferably 15°C/minute or more.
  • examples of the atmosphere during the cooling include, but are not limited to, a N 2 gas atmosphere or an inert gas atmosphere such as Ar.
  • the pressure during the cooling is not particularly limited, and may be increased or reduced.
  • examples of the pressure in the case of increasing the pressure as mentioned above include 100 kPa or more and 7000 kPa or less.
  • examples of the above-mentioned cooling step include a cooling step in which the above-mentioned sintered material is cooled to normal temperature in an Ar gas atmosphere.
  • raw material powders namely tungsten carbide (WC) powders, cobalt (Co) powder, chromium carbide (Cr 3 C 2 ) powder, and vanadium carbide (VC) powder
  • WC tungsten carbide
  • Co cobalt
  • Cr 3 C 2 chromium carbide
  • VC vanadium carbide
  • the raw material powders were mixed in the blended amounts shown in Table 1 and Table 2 to prepare mixed powders.
  • the "Blended amount [% by mass]" in Table 1 and Table 2 indicates the ratio of each raw material powder to the total mass of the mixed powder.
  • the mixing was performed with a ball mill for the mixing time described in Table 1 and Table 2.
  • the obtained mixed powders were spray-dried to prepare granulated powders.
  • the obtained granulated powders were press-molded to produce round rod-shaped compacts having a diameter of 6 mm.
  • the compacts were placed in a sintering furnace and sintered in vacuum under the conditions of temperatures shown in the "Sintering temperature [°C]” columns in Table 1 and Table 2 and times shown in the “Sintering time [h]” column in Table 1 to obtain sintered materials.
  • the sintered materials were cooled in an argon (Ar) gas atmosphere at temperature decreasing rates described in Table 1 and Table 2 to obtain cemented carbides.
  • the cemented carbides of each sample were measured for the compositions of the cemented carbides (the content of hard phases and the content of binder phases), the contents of tungsten carbide particles in the hard phases, the cobalt contents in the binder phases, D10/D90 in the hard phases, the average particle sizes of the hard phases, D10/D90 in the binder phases, the average particle sizes of the binder phases, the chromium contents, the vanadium contents, and the total area percent of the area of first vanadium-containing particles and the area of first chromium-containing particles in images obtained by photographing sections of the cemented carbides with a scanning electron microscope.
  • the contents of the hard phases in the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "Content of hard phases [% by volume]” columns in Table 3 and Table 4 describe the obtained results.
  • the contents of the binder phases in the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "Content of binder phases [% by volume]" columns in Table 3 and Table 4 describe the obtained results.
  • the contents of the tungsten carbide particles in the hard phases of the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "WC particles content in hard phases [% by mass]” columns in Table 3 and Table 4 describe the obtained results.
  • the cobalt contents in the binder phases of the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "Co content in binder phases [% by mass]” columns in Table 3 and Table 4 describe the obtained results.
  • D10/D90 in the hard phases of the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "D10/D90 (hard phases)" columns in Table 3 and Table 4 describe the obtained results.
  • D10/D90 in the binder phases of the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "D10/D90 (binder phases)" columns in Table 3 and Table 4 describe the obtained results.
  • the average particle sizes of the hard phases in the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "Average particle size of hard phases [ ⁇ m]” columns in Table 3 and Table 4 describe the obtained results.
  • the average particle sizes of the binder phases of the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "Average particle size of binder phases [ ⁇ m]" columns in Table 3 and Table 4 describe the obtained results.
  • the chromium contents in the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "Cr content [% by mass]” columns in Table 3 and Table 4 describe the obtained results.
  • the vanadium contents in the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "V content [% by mass]” columns in Table 3 and Table 4 describe the obtained results.
  • the total of the particle number of the first vanadium-containing particles and the particle number of the first chromium-containing particles in the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 were determined by the method described in Embodiment 1.
  • the "area percent of first V particles + first Cr particles [%]" columns in Table 3 and Table 4 describe the obtained results.
  • a cutting test was performed using cutting tools made of the cemented carbides of Sample Nos. 1 to 21, 25, and 27 to 34 under the following cutting conditions to evaluate the breakage resistance and the welding resistance.
  • the breakage resistance was evaluated based on the cutting length (m) when the breakage reached 100 ⁇ m. If the cutting length is more than 100 m, it is meant that the breakage resistance is excellent.
  • the welding resistance was evaluated based on the average welding width ( ⁇ m) at the time of breakage. If the welding width is 40 ⁇ m or less, it is meant that the welding resistance is excellent.
  • the "Breakage resistance [m]” columns and the “Welding resistance [ ⁇ m]” columns in Table 3 and Table 4 describe the obtained results (namely the cutting lengths and the welding widths).
  • the cemented carbides of Sample Nos. 1 to 4, 6 to 7, 9 to 14, 18 to 20, 25, 27 to 30, and 34 correspond to Examples. Meanwhile, Sample Nos. 5, 8, 15 to 17, 21, and 31 to 33 correspond to Comparative Examples. It was confirmed that the cutting tools made of the cemented carbides of Sample Nos. 1 to 4, 6 to 7, 9 to 14, 18 to 20, 25, 27 to 30, and 34 (Examples) were excellent in breakage resistance, and had long tool lives even in intermittent processing of titanium-based hard-to-cut materials as compared with the cutting tools made of the cemented carbides of Sample Nos. 5, 8, 15 to 17, 21, and 31 to 33 (Comparative Examples).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)
EP22935160.6A 2022-03-29 2022-03-29 Hartmetall Pending EP4357474A1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/015577 WO2023188012A1 (ja) 2022-03-29 2022-03-29 超硬合金

Publications (1)

Publication Number Publication Date
EP4357474A1 true EP4357474A1 (de) 2024-04-24

Family

ID=88200122

Family Applications (1)

Application Number Title Priority Date Filing Date
EP22935160.6A Pending EP4357474A1 (de) 2022-03-29 2022-03-29 Hartmetall

Country Status (5)

Country Link
EP (1) EP4357474A1 (de)
JP (1) JP7367905B1 (de)
CN (1) CN117677723A (de)
TW (1) TW202346615A (de)
WO (1) WO2023188012A1 (de)

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006328452A (ja) * 2005-05-24 2006-12-07 Hitachi Tool Engineering Ltd 微粒超硬合金製造用混合粉の製造方法及びその製造方法による微粒超硬合金粉
JP2009035810A (ja) 2007-07-11 2009-02-19 Sumitomo Electric Hardmetal Corp 超硬合金
JP2009024214A (ja) 2007-07-19 2009-02-05 Tungaloy Corp 超硬合金およびその製造方法
JP5289532B2 (ja) * 2011-10-07 2013-09-11 京セラ株式会社 超硬合金およびそれを用いた回転工具
JP2017171971A (ja) * 2016-03-22 2017-09-28 三菱マテリアル株式会社 熱伝導性にすぐれたｗｃ基超硬合金およびｗｃ基超硬合金製工具
JP7486711B2 (ja) * 2018-11-28 2024-05-20 株式会社Moldino Ｗｃ基超硬合金およびこれを用いた被覆切削工具
JP7385829B2 (ja) 2020-02-21 2023-11-24 三菱マテリアル株式会社 耐塑性変形性、耐欠損性にすぐれたｗｃ基超硬合金製切削工具および表面被覆ｗｃ基超硬合金製切削工具

Also Published As

Publication number Publication date
JPWO2023188012A1 (de) 2023-10-05
WO2023188012A1 (ja) 2023-10-05
JP7367905B1 (ja) 2023-10-24
TW202346615A (zh) 2023-12-01
CN117677723A (zh) 2024-03-08

Similar Documents

Publication Publication Date Title
EP3453776B1 (de) Hartmetall und schneidwerkzeug
EP3878992A1 (de) Hartmetall und dieses als basismaterial enthaltendes schneidwerkzeug
EP3502290A1 (de) Hartes material und schneidewerkzeug
EP3502079B1 (de) Titankarbonitridpulver und verfahren zur herstellung von titankarbonitridpulver
KR102552550B1 (ko) 서멧, 그것을 포함하는 절삭 공구 및 서멧의 제조 방법
EP4357474A1 (de) Hartmetall
CN111344255B (zh) 包含碳化钨的粉末
EP3871809A1 (de) Hartmetall und dieses als basismaterial enthaltendes schneidwerkzeug
EP4372115A1 (de) Hartmetall und schneidwerkzeug damit
JP6815574B1 (ja) 炭化タングステン粉末
EP4275822A1 (de) Hartmetall und schneidwerkzeug
EP4335944A1 (de) Hartmetall
EP4194576A1 (de) Sinterkarbid und schneidwerkzeug damit
EP4296390A1 (de) Hartmetall
EP4350022A1 (de) Hartmetall und dieses enthaltendes werkzeug
EP4249618A1 (de) Hartmetall und form für ultrahochdruckerzeugungsvorrichtung und verwendungen davon

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20240116

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR