WO2016084929A1 - Objet fritté à base de nitrure de bore cubique et outil coupant constitué d'un objet fritté à base de nitrure de bore cubique - Google Patents

Objet fritté à base de nitrure de bore cubique et outil coupant constitué d'un objet fritté à base de nitrure de bore cubique Download PDF

Info

Publication number
WO2016084929A1
WO2016084929A1 PCT/JP2015/083366 JP2015083366W WO2016084929A1 WO 2016084929 A1 WO2016084929 A1 WO 2016084929A1 JP 2015083366 W JP2015083366 W JP 2015083366W WO 2016084929 A1 WO2016084929 A1 WO 2016084929A1
Authority
WO
WIPO (PCT)
Prior art keywords
boron nitride
cubic boron
cbn
sintered body
binder phase
Prior art date
Application number
PCT/JP2015/083366
Other languages
English (en)
Japanese (ja)
Inventor
雅大 矢野
庸介 宮下
Original Assignee
三菱マテリアル株式会社
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
Priority claimed from JP2015229737A external-priority patent/JP6650106B2/ja
Application filed by 三菱マテリアル株式会社 filed Critical 三菱マテリアル株式会社
Priority to KR1020177014209A priority Critical patent/KR102503602B1/ko
Priority to EP15864025.0A priority patent/EP3225608B1/fr
Priority to US15/529,918 priority patent/US10391561B2/en
Priority to CN201580064126.8A priority patent/CN107001155B/zh
Publication of WO2016084929A1 publication Critical patent/WO2016084929A1/fr

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23B—TURNING; BORING
    • B23B27/00—Tools for turning or boring machines; Tools of a similar kind in general; Accessories therefor
    • B23B27/14—Cutting tools of which the bits or tips or cutting inserts are of special material
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/58—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides
    • C04B35/583—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on borides, nitrides, i.e. nitrides, oxynitrides, carbonitrides or oxycarbonitrides or silicides based on boron nitride

Definitions

  • the present invention relates to a cubic boron nitride (hereinafter sometimes referred to as “cBN”)-based sintered body (hereinafter also referred to as “cBN sintered body”) having high hardness.
  • cBN cubic boron nitride
  • cBN sintered body having high hardness.
  • cBN sintered body is a tool for cutting iron-based work materials such as steel and cast iron because it has the second highest hardness and thermal conductivity after diamond and has low affinity with iron-based materials. As such, it has been conventionally used favorably. In order to improve the performance as a cutting tool, some proposals have been made so far in order to further improve the strength, toughness, hardness and the like of the cBN sintered body.
  • Patent Document 1 discloses that when a cBN sintered body is produced by ultra-high pressure sintering, a binder phase is a skeleton structure, cBN particles which are hard particles in a binder phase structure, Al boride and nitride, and It has been proposed to improve the strength and toughness of a cBN sintered body by forming a structure in which a reaction product made of Ti boride is dispersed and distributed.
  • Patent Document 2 in the cBN sintered body, in order to remove oxygen adsorbed on the surface of the cBN grains when the cBN particles are combined, Ti and Al are used as raw materials to act as oxygen getters, Prevents alteration of cBN particles due to solid solution of oxygen inside the cBN grains, and forms a structure having a continuous structure in which the cBN particles are bonded to each other and a bonded structure in which the bonded phases are bonded to each other. By doing so, it has been proposed to achieve both improvement in heat resistance and improvement in toughness of the cBN sintered body.
  • a cBN sintered body for a cutting tool disclosed in Patent Document 1 has a binder phase as a skeleton structure, cBN particles which are hard particles in a binder phase structure, Al boride and nitride, and Ti boride. It has a structure in which a reaction product consisting of is distributed and distributed.
  • a cBN sintered body having such a structure is used as a cutting tool, if the cBN content in the sintered body is increased in order to apply to cutting conditions with a high load on the cutting edge, the cBN particles are brought into contact with each other and bonded.
  • this unsintered portion has lower strength than the portion where the cBN grains and the binder phase are in contact with each other, there is a problem that the hardness according to the cBN content cannot be obtained as the cBN content increases. It was.
  • a cBN sintered body having insufficient hardness is used as a tool, cracks starting from the portions where the cBN grains are in contact with each other tend to occur. Therefore, when such a tool is used for intermittent cutting with a high load on the cutting edge, there is a problem that the cutting edge tends to be lost and the tool life is short.
  • the present inventors paid attention to the binder existing between the cBN particles and the cBN particles, and conducted earnest research to improve the hardness of the cBN sintered body. As a result, the following knowledge was obtained. Obtained.
  • cBN powder which is a constituent component of cBN sintered body, is mixed with TiN powder, TiAl 3 powder, Al 2 O 3 powder, etc., which are binder phase forming components, and these are mixed under ultra high pressure and high temperature conditions. It was made by sintering underneath.
  • ALD Atomic Layer Deposition
  • a very thin AlN film is formed by the method or the like, and then heated under vacuum, and then a pretreatment including a step of peeling the AlN film by ball mill mixing is performed.
  • cBN particles having a high surface cleanliness from which impurity components such as oxygen adhering to and adsorbing on the surface of the cBN particles are removed are obtained.
  • this cBN particle was used as a raw material and sintered under a super high pressure condition together with a binder phase forming component to produce a cBN sintered body, the oxygen content in the binder phase existing between the cBN particles and the cBN particles ( However, the value of the atomic ratio of the oxygen content to the Al content) becomes a small value, the oxide in the binder phase between the cBN particles and the cBN particles can be reduced, and a strong binder phase can be formed.
  • the present inventors have found that, in the cBN sintered body of the present invention, a cBN sintered body having high hardness can be obtained even when the content ratio of cBN contained in the sintered body is increased. It was.
  • the present invention has been made based on the above findings, “(1) In a cubic boron nitride-based sintered body containing 70 to 95 vol% of cubic boron nitride particles, when the cross-sectional structure of the sintered body was observed, the adjacent cubic boron nitride particles A binder phase having a width of 1 nm or more and 30 nm or less exists, the binder phase is composed of a compound containing at least Al, B, and N, and the ratio of the oxygen content to the Al content in the binder phase is A cubic boron nitride-based sintered body having an atomic ratio of 0.1 or less (however, the atomic ratio).
  • an average particle size of the cubic boron nitride particles is 0.5 to 8.0 ⁇ m, and a cross-sectional structure of the cubic boron nitride-based sintered body ,
  • the width between adjacent cubic boron nitride particles is The presence of the cubic boron nitride particles in which a binder phase of 1 nm to 30 nm is present and the ratio of the oxygen content to the Al content in the binder phase is 0.1 or less is the total number of viewing fields.
  • Elementary particles are present in an average particle number ratio of 0.4 or more with respect to the total number of cubic boron nitride particles in the observation cross section, and between adjacent cubic boron nitride particles.
  • the ratio of the oxygen content to the Al content in the binder phase is 0.1 or less.
  • the number is present at an average ratio of 0.5 or more with respect to the number of the cubic boron nitride particles in which a binder phase having a width of 1 nm or more and 30 nm or less exists between the adjacent cubic boron nitride particles.
  • the binder phase having a width of 1 nm or more and 30 nm or less present between the cubic boron nitride particles is interspersed between the cubic boron nitride particles
  • the cBN sintered body of the present invention contains 70 to 95 vol% of cBN particles having an average particle diameter of preferably 0.5 to 8.0 ⁇ m, and when the cross-sectional structure of the sintered body is observed, adjacent cBN A bonded phase having a width of 1 nm to 30 nm exists between the particles, and the bonded phase is composed of a compound containing at least Al, B, and N, and has an oxygen content with respect to the Al content in the bonded phase.
  • the ratio is 0.1 or less. Therefore, there are few oxides in the binder phase between cBN particles and cBN particles, the binder phase is strong, and there are few unsintered portions where the cBN particles are in contact with each other and cannot sufficiently react with the binder phase. As a result, this sintered body exhibits high hardness even when the content ratio of cBN particles is large. Moreover, the cutting tool using the cBN sintered body of the present invention exhibits excellent fracture resistance and can extend the tool life.
  • HAADF high angle scattering annular dark field by STEM (scanning transmission electron microscope) of the interface between cBN particles of a cBN sintered body (hereinafter also referred to as “the present invention cBN sintered body”) according to an embodiment of the present invention.
  • Image 80,000 times
  • the binarized image (80,000 times) of the B mapping image by STEM of the interface between the cBN particles of the cBN sintered body of the present invention is shown.
  • the binarized image (80000 times) of the N mapping image by STEM of the interface between the cBN particles of the cBN sintered body of the present invention is shown.
  • FIG. 5 is a diagram showing a region where B, N, and Al overlap in FIGS. It is a figure which shows the state which carried out the ellipse approximation of the area
  • FIG. 6 it is the figure which drawn the interface outline line which consists of a polygonal line which connected the midpoint of the short axis of each ellipse with the straight line.
  • the interface outline line between the cBN particles obtained from the Al mapping image, the B mapping image, and the N mapping image of the interface between the cBN particles of the cBN sintered body of the present invention is shown.
  • the direction perpendicular to the interface outline (the arrow direction in FIG. 9) is shown.
  • FIG. 6 shows the width of a binder phase between cBN particles and a partially enlarged view thereof obtained from FIG. 5 and an interface outline.
  • the binarized image of the Al mapping image (80000 times) by STEM of the interface between the cBN particles of the cBN sintered body of the present invention and a measurement region with a width of 30 nm centering on the interface outline line are shown.
  • the method for measuring the number ratio (q / Q) of cBN particles in which a binder phase having a width of 1 nm to 30 nm exists between the cBN particles in the cBN sintered body of the present invention, and the oxygen content relative to the Al content in the binder phase It is a schematic diagram which shows the measuring method of the particle number ratio (n / N) whose ratio is 0.1 or less.
  • the cBN sintered body according to the present embodiment includes cBN particles having a volume ratio of 70 to 95 vol% with respect to the volume of the entire cBN sintered body, and a binder phase that binds the cBN particles to each other. Further, when the cross-sectional structure of this sintered body is observed, a binder phase having a width of 1 nm or more and 30 nm or less exists between adjacent cBN particles.
  • this binder phase contains at least Al (aluminum), B (boron), and N (nitrogen), and the ratio of O content to Al content in the binder phase is 0.1 or less (provided that (Atom ratio calculated from area ratio on the cross section).
  • the above-mentioned binder phase having a width of 1 nm or more and 30 nm or less that exists between adjacent cBN particles may be interspersed between adjacent cBN particles, and one binder phase extends between the cBN particles.
  • CBN particles may be adjacent to other cBN particles through one of the above-mentioned binder phases).
  • the cBN sintered body of the present embodiment includes a step of pre-processing the surface of the cBN particles, a step of mixing the pre-processed cBN particles with the raw material powder constituting the binder phase, And a process of sintering the body.
  • the pretreatment of the cBN particle surface is performed as follows, for example. First, for example, in the ALD method, an AlN film is formed on the surface of cBN particles.
  • cBN particles are charged into a fluidized bed furnace, the temperature inside the furnace is raised to about 350 ° C., Ar + Al (CH 3 ) 3 gas inflow process, Ar gas purge process, Ar + NH 3 gas inflow process, Ar gas purge The process is defined as one cycle, and this cycle is repeated until a desired AlN film thickness is obtained. For example, by forming the film over 30 minutes, an AlN film having a thickness of about 5 nm can be formed on the cBN particle surface.
  • the cBN particles having an AlN film having a predetermined thickness formed thereon are heated at about 1000 ° C. under vacuum to diffuse impurity elements such as oxygen on the cBN surface into the AlN film. To capture.
  • the AlN film in which the impurity element is trapped is peeled off from the cBN surface by ball mill mixing.
  • cBN particles having a high surface cleanliness from which impurity components such as oxygen adsorbed on the cBN surface are removed are obtained.
  • the pretreatment of the cBN particle surface is not limited to the above-described ALD method, but may be any method that can remove the impurity component on the cBN particle surface.
  • the cBN particles subjected to the above pretreatment are used as raw materials, and further, for example, TiN powder, Al powder, TiAl 3 powder, and Al 2 O 3 powder are used as raw material powders, and these raw material powders have a predetermined composition.
  • a molded body having a predetermined size is prepared.
  • the compact is charged into a normal ultra-high pressure sintering apparatus and subjected to ultra-high pressure and high temperature sintering for a predetermined time under sintering conditions of a pressure of 5 GPa or higher and a temperature of 1600 ° C. or higher.
  • the cBN sintered body of the embodiment can be produced.
  • the cBN sintered body according to the present embodiment can be obtained by producing the cBN sintered body using the cBN particles from which the impurity components on the surface have been removed by the pretreatment.
  • a normal ultra-high pressure is used.
  • this Ti compound and Al boride have low adhesion strength with cBN particles. For this reason, when used as a cutting tool, the interface between the Ti compound or Al boride and cBN particles tends to be the starting point of cracks, resulting in a decrease in fracture resistance. Therefore, it is not preferable that the content ratio of cBN particles in the cBN sintered body is less than 70 vol%. On the other hand, when the content ratio of cBN particles exceeds 95 vol%, when used as a cutting tool, voids that are the starting points of cracks are easily generated in the sintered body, and the fracture resistance is reduced.
  • the content ratio of cBN particles in the cBN sintered body is 70 to 95 vol%.
  • the content ratio of cBN particles in the cBN sintered body is preferably 70 to 90 vol%, more preferably 75 to 85 vol%, but is not limited thereto.
  • the content ratio of the cBN particles in the cBN sintered body is determined by observing the cross-sectional structure of the cBN sintered body with the SEM, and the portion corresponding to the cBN particles in the obtained secondary electron image is the same image as described above. Extract by processing. The area occupied by the cBN particles is calculated by image analysis, the ratio of the cBN particles in one image is calculated, and the average value of the content ratio of the cBN particles obtained by processing at least three images is set in the cBN sintered body. Obtained as the content of occupied cBN particles.
  • a square region having one side that is five times the average particle size of the cBN particles be an observation region used for image processing.
  • a visual field area of about 15 ⁇ m ⁇ 15 ⁇ m is desirable.
  • the average particle size of the cBN particles used in the present embodiment is not particularly limited, but is preferably in the range of 0.5 to 8 ⁇ m. This is due to the following reason.
  • cBN particles having an average particle size of 0.5 ⁇ m to 8 ⁇ m are dispersed in the sintered body, so that cBN particles on the tool surface are used during tool use. Chipping that originates from the uneven shape of the cutting edge caused by dropping off can be suppressed.
  • the propagation of cracks that propagate from the interface between the cBN particles and the binder phase caused by the stress applied to the blade edge during use of the tool, or the cracks that propagate through the cBN particles, is caused by the cBN particles dispersed in the sintered body. Can be suppressed. Therefore, such a cutting tool has excellent fracture resistance. Therefore, the average particle size of the cBN particles used in this embodiment is preferably in the range of 0.5 to 8 ⁇ m, and more preferably in the range of 0.5 to 3 ⁇ m.
  • the average particle size of the cBN particles can be determined as follows.
  • the cross-sectional structure of the cBN sintered body is observed by SEM.
  • a secondary electron image of 15 ⁇ m ⁇ 15 ⁇ m is obtained.
  • a portion corresponding to cBN particles in the obtained image is extracted by image processing, and a maximum length of a portion corresponding to each particle extracted by image analysis is obtained by the following procedure.
  • the image is displayed in monochrome with 256 gradations, with 0 being black and 255 being white.
  • Binarization processing is performed so that the cBN particles are black using an image of pixel values in which the ratio of the pixel value of the particle portion to the pixel value of the binder phase portion is 2 or more.
  • the pixel values of the cBN particle part and the binder phase part are obtained from an average value in a region of about 0.5 ⁇ m ⁇ 0.5 ⁇ m. It is desirable to obtain an average value of pixel values in at least three different regions in the same image, and use the average value as each contrast.
  • cBN particles that are considered to be in contact using watershed which is one of image processing operations, such as separation of parts that are considered to be in contact with each other. Separate each other.
  • the portion corresponding to cBN particles (black portion) in the image obtained after the above processing is subjected to particle analysis, and the maximum length of the portion corresponding to each particle is obtained.
  • the obtained maximum length is defined as the maximum length of each particle, and this is defined as the diameter of each particle. From this diameter, the volume of each particle is calculated using each particle as a sphere. Based on the obtained volume of each particle, an integrated distribution of particle diameters is obtained.
  • the sum of the volume and the volume of particles having a diameter equal to or smaller than the diameter of the particle is obtained as an integrated value.
  • a graph is drawn with the volume percentage [%], which is a ratio of the total value of each particle with respect to the total volume of all particles, as the vertical axis and the horizontal axis as the diameter [ ⁇ m] of each particle.
  • the value of the diameter (median diameter) at which the volume percentage is 50% is taken as the average particle size of cBN particles in one image.
  • the average value of the average particle size values obtained by performing the above processing on at least three images is defined as the average particle size [ ⁇ m] of the cBN particles of the cBN sintered body.
  • a length ( ⁇ m) per pixel is set using a scale value known in advance by SEM. Further, in the particle analysis, in order to remove noise, a region having a diameter smaller than 0.02 ⁇ m is not calculated as a particle.
  • HAADF high angle scattering annular dark field
  • the thickness of the observation sample is preferably 3 nm to 70 nm. If it is thinner than 3 nm, the amount of characteristic X-rays to be detected is small at the time of element mapping, which is not preferable because it takes time for measurement and the sample is easily damaged. On the other hand, if it is thicker than 70 nm, analysis of the image becomes difficult, which is not preferable.
  • the observation image has an image size of about 500 nm in length ⁇ about 500 nm in width to about 150 nm in length ⁇ 150 nm in width, and a resolution of 512 ⁇ 512 pixels or more.
  • Mapping images of boron (B), nitrogen (N), aluminum (Al), and oxygen (O) elements are acquired at the observation site. These images are images converted to atm% of these four elements for the purpose of removing the background (images converted to the ratio of the content of each element (atm%) to the total content of the four elements). ).
  • the width of the binder phase is determined as follows. (B1) When the binder phase is interposed between the cBN particles, that is, when there is one Al island overlapping the region where B and N exist (when one binder phase extends between the cBN particles) First, in the mapping image of Al, a long axis is obtained when the Al island corresponding to the binder phase is approximated as an ellipse.
  • the Al island overlapping the region where B and N are present is extracted by image processing in the same manner as the processing performed in the measurement of the average particle size of the cBN particles, and is analyzed by image analysis.
  • the longest axis is the maximum length when the extracted island is approximated to an ellipse. This long axis is defined as an interface outline line between cBN particles.
  • B2 When the binder phase is scattered at the interface between the cBN grains, that is, when the Al island overlapping the region where B and N exist is divided into two or more, B and N
  • the Al islands that overlap the region where the slab exists are extracted by image processing (FIG.
  • the average value of the width measured at least at three or more locations is defined as the width of the binder phase existing between the cBN particles.
  • the width is 1 nm or more and 30 nm or less, it is assumed that the width of the binder phase existing between the cBN particles is 1 nm or more and 30 nm or less.
  • the width of the binder phase existing between the cBN particles is 1 nm or more and 30 nm or less.
  • the cBN sintered body when there is no binder phase having a width of 1 to 30 nm including Al, B, and N between adjacent cBN particles, sufficient strength to adhere between the cBN particles and the cBN particles cannot be obtained. Or breakage starting from the inside of the binder. As a result, a sintered body having a low hardness is obtained, which is not preferable.
  • (C) the content of Al and the content of O contained in the binder phase are determined as follows. First, using a binarized image of the mapping image of Al and O (FIGS. 11 and 12), a measurement region M having a width of 30 nm around the interface outline confirmed in (b) above is determined. This region M was surrounded on both sides of the interface outline by two lines parallel to and congruent to the interface outline with a distance of 15 nm from the interface outline and two straight lines connecting the ends. It is an area. A content (area%) of Al and O in a portion where B, N, and Al included in the region M overlap is obtained.
  • the area of Al where B, N, and Al existing in this region M overlap is obtained from an image obtained by binarizing the Al mapping image, and the ratio of the area of Al to the area of this region is calculated as follows: The content of Al contained in the binder phase. Similarly, for O, the ratio of the area of O to the area of the region M is obtained, and this is defined as the content of O contained in the binder phase. The ratio (area%) of the area of Al and O contained in the binder phase thus obtained is defined as the content (atomic ratio) of Al and O, respectively. (D) From the Al and O contents (area%) determined above, the ratio of the oxygen content to the Al content in the binder phase (hereinafter sometimes referred to as “O / Al”) is calculated. .
  • component analysis is performed on a binder phase having a width of 1 nm or more and 30 nm or less present in a region of 30 nm width centered on a rough interface line defined between adjacent cBN particles.
  • the value of O / Al in the binder phase can be obtained.
  • the binder phase interspersed with or having a width of 1 nm or more and 30 nm or less at the interface between adjacent cBN particles is composed of a component containing at least Al, B, and N (see FIGS. 2 to 12). ).
  • a binder phase having a width of 1 nm or more and 30 nm or less exists between adjacent cBN particles.
  • component analysis in the bonded phase is performed, and the value of O / Al in the bonded phase can be obtained.
  • “Dispersed” indicates a state in which Al is present in a plurality of islands in a portion where Al, B, and N overlap
  • “interposed” indicates that Al is present in a portion in which Al, B, and N overlap. Indicates a state that exists without interruption.
  • the binder phase having a width of 1 nm or more and 30 nm or less that exists between the adjacent cBN particles contains at least Al, B, and N.
  • the main structure of the binder phase is composed of Al, B, and N (see FIGS. 2 to 12).
  • ⁇ Abundance ratio of cBN particles in which a binder phase with a width of 1 nm to 30 nm exists between adjacent cBN particles An abundance ratio of cBN particles in which a binder phase having a width of 1 nm or more and 30 nm or less exists between adjacent cBN particles is measured. In other words, the abundance ratio (q / Q) of cBN particles in which a binder phase having a width of 1 nm or more and 30 nm or less exists between adjacent cBN particles to all cBN particles is measured. For example, this measurement can be specifically performed as follows. First, as shown in the schematic diagram of FIG.
  • a square region in which the length L of one side is five times the average particle size of cBN particles is defined as one measurement visual field range A.
  • the average particle size of cBN particles is 1 ⁇ m
  • a square region of 5 ⁇ m ⁇ 5 ⁇ m is set as one measurement visual field range.
  • pull the diagonal D from the top of the measurement region A which forms a square it counts the number of particles to Q 1 cBN particles 1 according to the diagonal D.
  • whether or not the binder phase 2 having a width of 1 nm or more and 30 nm or less exists between the adjacent cBN particles 1 is specified by the above-described method.
  • the number of particles q 1 of the cBN particles 1 specified to be present between the adjacent cBN particles 1 and having a width of 1 nm or more and 30 nm or less is counted, and the value of q 1 / Q 1 is calculated.
  • the same measurement is performed for at least five visual fields, the value of q n / Q n in each visual field is calculated, and then the average value of these values is obtained as the value of q / Q.
  • the q / Q value is desirably 0.4 or more.
  • the upper limit value of q / Q is preferably 1, and q / Q is more preferably 0.6 or more and 1 or less.
  • the binder phase present between the adjacent cBN particles identified as described above and having a width of 1 nm to 30 nm and present in the region measured as described above.
  • the presence or absence of a region where the Al value is 0.1 or less is observed.
  • the number of fields in which at least one binder phase is observed is 60% or more of the total number of fields. It is more preferable that observation is performed in a field of view of 80% or more of the total number of observation fields, and it is further preferable that the region is observed in all observation fields of view (observed in 100% of the total number of observation fields).
  • the number of cBN particles in which the O / Al of this binder phase is 0.1 or less (n)
  • the ratio (n / N) to the number (N) of cBN particles in which a binder phase having a width of 1 nm to 30 nm is present between the cBN particles and the adjacent cBN particles can be performed as follows.
  • cBN particles 1 on the diagonal line D drawn from the top of one square measurement visual field region A whose side length L is five times the average particle size of the cBN particles adjacent cBN particles 1 and CBN particles 1 in which a binder phase 2 having a width of 1 nm or more and 30 nm or less is present in between, and the number N 1 is counted.
  • O / Al in the binder phase 2 is 0.1 or less (however, the area ratio).
  • n 1 of cBN particles 1 is counted, and the value of n 1 / N 1 is calculated.
  • the same measurement is performed for at least five visual fields, and the value of n n / N n in each visual field is calculated. Then, an average value of these values is obtained and set as a value of n / N.
  • the value of n / N is desirably 0.5 or more. That is, the number (n) of cBN particles having an O / Al ratio of 0.1 or less in the binder phase existing between adjacent cBN particles and having a width of 1 nm or more and 30 nm or less is the width between adjacent cBN particles.
  • n / N is 0.5 or more, a strong binder phase can be formed between the cBN particles and the cBN particles, and high hardness is exhibited.
  • the value of n / N is preferably 0.6 or more, and more preferably 0.8 or more and 1 or less.
  • the cBN sintered body of the present embodiment is composed of cBN particles and a binder phase as described above.
  • the binder phase the configuration of the binder phase formed in the sintered body other than the binder phase having a width of 1 nm to 30 nm existing between adjacent cBN particles is not particularly limited, but the binder phase formed in this region is not limited. Is composed of one or more of Ti nitride, carbide, carbonitride, boride, Al nitride, boride, oxide and two or more of these solid solutions and unavoidable impurities. It is preferable.
  • the cBN sintered body according to the present embodiment described above has a high content ratio of cBN particles and exhibits a hardness higher than the hardness according to the cBN content.
  • the Vickers hardness H of the cBN sintered body satisfies the following formula. H> ⁇ 0.42C 2 + 81.5C (C is the content of cBN particles (vol%))
  • CBN particles having a median diameter (D50) shown in Table 1 were used as a base material, and an AlN film having an average film thickness shown in Table 1 was coated on the cBN particles by an ALD (Atomic Layer Deposition) method. More specifically, cBN particles having a median diameter (D50) shown in Table 1 are charged into the furnace, the temperature inside the furnace is raised to 350 ° C., and a precursor of Al is used as a film forming gas.
  • a certain Al (CH 3 ) 3 gas and NH 3 gas as a reaction gas (1) Ar + Al (CH 3 ) 3 gas inflow process, (2) Ar gas purge step, (3) Ar + NH 3 gas inflow process, (4) Ar gas purging step
  • the above (1) to (4) were set as one cycle, and this cycle was repeated until the AlN film reached the target film thickness.
  • an AlN film having a predetermined thickness was formed on the surface of the cBN particles.
  • the cBN particle powder coated with the AlN film obtained by the above procedure was observed using an SEM (scanning electron microscope).
  • an AlN film having an average film thickness shown in Table 1 was formed on the surface of the cBN particle. It was confirmed that it was coated.
  • the cBN particles on which the AlN film was formed were heat-treated under a vacuum at a temperature of about 1000 ° C. for 30 minutes to diffuse impurity elements such as oxygen on the cBN surface into the AlN film.
  • the AlN film in which the impurity element was captured was peeled off from the cBN surface by ball mill mixing using a tungsten carbide container and balls.
  • CBN particle powder having a predetermined median diameter prepared by the above procedure, and TiN powder, TiC powder, Al powder, TiAl 3 powder, and WC powder having an average particle diameter in the range of 0.3 to 0.9 ⁇ m. It was prepared as a raw material powder for forming a binder phase. Blended so that the content ratio of cBN particle powder is 70 to 95 vol% when the total amount of some raw material powder selected from these raw material powders and cBN particle powder is 100 vol%, wet-mixed, Dried. Then, it was press-molded into a size of diameter: 50 mm ⁇ thickness: 1.5 mm at a molding pressure of 1 MPa with a hydraulic press to obtain a molded body.
  • the compact was heat-treated in a vacuum atmosphere at a pressure of 1 Pa at a predetermined temperature within a range of 1000 to 1300 ° C. for 30 to 60 minutes, and charged into a normal ultrahigh pressure sintering apparatus under normal conditions.
  • the cBN sintered bodies 1 to 17 of the present invention shown in Table 2 were prepared by sintering under high pressure and high temperature under the conditions of pressure: 5 GPa, temperature: 1600 ° C., and holding time: 30 minutes.
  • the binder phase structure other than cBN of the sintered body shown in Table 2 was confirmed by XRD (X-ray Diffraction) of the cBN sintered body.
  • the above production process is preferably performed so as to prevent oxidation of the raw material powder in the process up to ultra-high pressure sintering. Specifically, the raw material powder and the molded body are handled in a non-oxidizing protective atmosphere. It is preferable to do.
  • cBN particle powders a, b, e to i having a median diameter (D50) shown in Table 4 that were not coated with an AlN film by an ALD (Atomic Layer Deposition) method were used as a raw material powder.
  • the heat treatment under vacuum of the film and the peeling process of the AlN film from the cBN surface were not performed.
  • after coating an AlN film having an average film thickness shown in Table 4 after heat treatment under vacuum at a temperature of about 1000 ° C.
  • CBN particle powders c and d having a median diameter (D50) shown in Table 4 were prepared by peeling off the AlN film from the cBN surface.
  • TiN powder, TiC powder, Al powder, TiAl 3 powder, and WC powder having an average particle diameter in the range of 0.3 to 0.9 ⁇ m are prepared as binder phase forming raw material powders, and selected from these raw material powders.
  • the cBN sintered bodies 1 to 17 of the present invention were blended so that the content ratio of the cBN particle powder was 55 to 98.2 vol% when the total amount of the raw material powder and the cBN particle powder was 100 vol%.
  • Comparative Example cBN sintered bodies 1 to 10 shown in Table 5 were produced in the same manner as described above.
  • the average particle size ( ⁇ m) of cBN particles and the content ratio (vol%) of cBN particles were calculated.
  • the median diameter in the volume integration% and diameter distribution curve was obtained from one image, and the average value obtained from at least three images was defined as the average particle size ( ⁇ m) of cBN.
  • the observation area used for image processing was 15 ⁇ m ⁇ 15 ⁇ m.
  • the calculated average particle diameters are shown in Tables 2 and 5.
  • component analysis and measurement of O / Al in a binder phase having a width of 1 nm to 30 nm existing between adjacent cBN particles were performed as described above. That is, after polishing the cross section of the cBN sintered body, the interface where the cBN particles and the cBN particles are adjacent to each other is observed using a TEM, and mapping images of B, N, Al, and O elements are observed at the observation points (FIG. 2 to FIG. 2). 4, 11, 12). Next, it was confirmed from the mapping image of B and N that it was an observation place between the cBN particles.
  • the Al mapping image, the B mapping image, and the N mapping image were superposed, and an interface outline line between the cBN particles was obtained from the portion where Al, B, and N overlapped as described above. Moreover, it confirmed that the width
  • the content (area ratio) of Al and O was determined in a region having a width of 30 nm centered on the interface outline line confirmed above. . From the Al and O contents (area ratio) determined above, O / Al in the binder phase of the region was calculated.
  • the identification of the cBN particle in which a binder phase having a width of 1 nm or more and 30 nm or less exists between adjacent cBN particles and measurement of the abundance ratio (q / Q) of the cBN particles were performed as described above. That is, as shown in the schematic diagram of FIG. 13, a region of 5 times the average particle size of cBN particles is defined as one measurement visual field range, a diagonal line is drawn from the top of the measurement region forming a square, and the cBN particles applied to the diagonal line counting the number of particles Q 1 of.
  • the number of observation fields in which a binder phase having a width of 1 nm or more and 30 nm or less exists between adjacent cBN particles and a region having an O / Al value of 0.1 or less in the binder phase is obtained. It was. The results are shown in Tables 3 and 6 as the number of viewing fields. Note that the number of observation fields in the table is centered on the interface outline line obtained from the bonding phase in which a bonding phase having a width of 1 nm to 30 nm exists between adjacent cBN particles in a total of 10 observation fields. The number of visual fields in which a region where the value of O / Al in the binder phase in the region having a width of 30 nm is 0.1 or less is observed.
  • n 1 was counted.
  • the value of n 1 / N 1 is calculated, the same measurement is performed for a total of 10 visual fields, the value of n n / N n in each visual field is calculated, and then the average value of these values is the value of n / N Asked.
  • n / N in the table is O / Al in the binder phase in the region having a width of 30 nm centered on the interface outline line, with a binder phase having a width of 1 nm to 30 nm between adjacent cBN particles.
  • “-” In the table indicates that there is a binder phase with a width of 1 nm or more and 30 nm or less between adjacent cBN particles, but there is no overlap of Al, B, and N elements by element mapping, and the interface outline is defined. This means that O / Al cannot be calculated because it is not possible.
  • FIG. 14 is a graph plotting the relationship between the cBN content C (vol%) obtained from Tables 2 and 4 and the Vickers hardness H (HV).
  • the binder phase between the cBN particles and the cBN particles has an average O / Al of 0.10 or less.
  • there was little oxide and the strong binder phase was formed.
  • the number of visual fields in which a binder phase having a width of 1 nm or more and 30 nm or less exists between adjacent cBN particles and the O / Al value in the binder phase is 0.1 or less was observed. Since it was 60% or more of the number of fields of view, there were many unsintered portions where the cBN particles were in contact with each other and could not sufficiently react with the binder phase.
  • the Vickers hardness (HV) remained at 3690 although the cBN content was higher than the range specified in the present embodiment.
  • High hardness was shown.
  • the comparative example cBN sintered body 6 has a high cBN content ratio and a Vickers hardness (HV) of 3710, which is the same as the Vickers hardness (HV) 4210 of the present cBN sintered body 8 having the same cBN content ratio. And it was low hardness.
  • the other comparative cBN sintered bodies 1, 2, 5, and 7 to 10 each had an O / Al average of 0.73 or more and a Vickers hardness (HV) of 3560 or less and a low hardness. It was.
  • the comparative cBN sintered bodies 1 to 10 were all located below the curve. From these facts, when comparing the hardness of the cBN sintered body with the same cBN content, the hardness of the cBN sintered body of the present invention is much higher than that of the comparative cBN sintered body. it is obvious.
  • the curve in FIG. 14 represents the relationship between the cBN particle content of the cBN sintered body obtained empirically and the Vickers hardness.
  • the cBN sintered body of the present invention has high hardness and high bond strength between the cBN particles and the binder phase. Therefore, for example, when used as a cBN cutting tool in which a high load acts on the cutting edge, it is excellent in abnormal damage resistance such as defects, and exhibits excellent wear resistance over a long period of use. Application as fracture-resistant materials such as tool materials is expected.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)
  • Ceramic Products (AREA)

Abstract

La présente invention concerne un objet fritté à base de nitrure de bore cubique, l'objet fritté comprenant 70 à 95 % en volume de grains de nitrure de bore cubique. Lorsque la structure d'une section transversale de l'objet fritté est examinée, une phase de liant ayant une largeur de 1 à 30 nm est observée entre les grains de nitrure de bore cubique adjacents, la phase de liant étant constituée d'un composé contenant au moins Al, B et N, le rapport entre la teneur en oxygène et la teneur en Al dans la phase de liant étant de 0,1 ou moins (en termes de rapport atomique).
PCT/JP2015/083366 2014-11-27 2015-11-27 Objet fritté à base de nitrure de bore cubique et outil coupant constitué d'un objet fritté à base de nitrure de bore cubique WO2016084929A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
KR1020177014209A KR102503602B1 (ko) 2014-11-27 2015-11-27 입방정 질화붕소기 소결체 및 입방정 질화붕소기 소결체제 절삭 공구
EP15864025.0A EP3225608B1 (fr) 2014-11-27 2015-11-27 Matière fritté à base de nitrure de bore cubique et outil coupant constitué d'une matière fritté à base de nitrure de bore cubique
US15/529,918 US10391561B2 (en) 2014-11-27 2015-11-27 Cubic boron nitride-based sintered material and cutting tool made of cubic boron nitride-based sintered material
CN201580064126.8A CN107001155B (zh) 2014-11-27 2015-11-27 立方晶氮化硼基烧结体及立方晶氮化硼基烧结体制切削工具

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2014-240418 2014-11-27
JP2014240418 2014-11-27
JP2015229737A JP6650106B2 (ja) 2014-11-27 2015-11-25 立方晶窒化ほう素基焼結体および立方晶窒化ほう素基焼結体製切削工具
JP2015-229737 2015-11-25

Publications (1)

Publication Number Publication Date
WO2016084929A1 true WO2016084929A1 (fr) 2016-06-02

Family

ID=56074476

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2015/083366 WO2016084929A1 (fr) 2014-11-27 2015-11-27 Objet fritté à base de nitrure de bore cubique et outil coupant constitué d'un objet fritté à base de nitrure de bore cubique

Country Status (1)

Country Link
WO (1) WO2016084929A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017204152A1 (fr) * 2016-05-23 2017-11-30 三菱マテリアル株式会社 Outil de coupe fait d'un corps fritté en nitrure de bore cubique
GB2560642A (en) * 2017-03-15 2018-09-19 Element Six Uk Ltd Sintered polycrystalline cubic boron nitride material
US10954165B2 (en) 2016-04-11 2021-03-23 Iljin Diamond Co., Ltd. Polycrystalline cubic boron nitride and method for preparing same
US11396482B2 (en) * 2018-09-19 2022-07-26 Sumitomo Electric Industries, Ltd. Cubic boron nitride sintered material, cutting tool including cubic boron nitride sintered material, and method of producing cubic boron nitride sintered material

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS569279A (en) * 1979-06-28 1981-01-30 Sumitomo Electric Industries Sintered body for cutting tool and its manufacture
JPH02236253A (ja) * 1989-03-10 1990-09-19 Sumitomo Electric Ind Ltd 工具用高硬度焼結体
JPH061666A (ja) * 1992-06-18 1994-01-11 Kyocera Corp 立方晶窒化硼素質焼結体およびその製造方法
JPH0616476A (ja) * 1992-06-30 1994-01-25 Kyocera Corp 立方晶窒化硼素質焼結体およびその製造方法
JPH10218666A (ja) * 1996-12-03 1998-08-18 Sumitomo Electric Ind Ltd 高圧相型窒化硼素基焼結体
JP2004026555A (ja) * 2002-06-25 2004-01-29 Toshiba Tungaloy Co Ltd 立方晶窒化ホウ素含有焼結体およびその製造方法
WO2007145071A1 (fr) * 2006-06-12 2007-12-21 Sumitomo Electric Hardmetal Corp. Fritte composite
JP2011212832A (ja) * 2010-03-19 2011-10-27 Mitsubishi Materials Corp 立方晶窒化ほう素基超高圧焼結材料製切削工具

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS569279A (en) * 1979-06-28 1981-01-30 Sumitomo Electric Industries Sintered body for cutting tool and its manufacture
JPH02236253A (ja) * 1989-03-10 1990-09-19 Sumitomo Electric Ind Ltd 工具用高硬度焼結体
JPH061666A (ja) * 1992-06-18 1994-01-11 Kyocera Corp 立方晶窒化硼素質焼結体およびその製造方法
JPH0616476A (ja) * 1992-06-30 1994-01-25 Kyocera Corp 立方晶窒化硼素質焼結体およびその製造方法
JPH10218666A (ja) * 1996-12-03 1998-08-18 Sumitomo Electric Ind Ltd 高圧相型窒化硼素基焼結体
JP2004026555A (ja) * 2002-06-25 2004-01-29 Toshiba Tungaloy Co Ltd 立方晶窒化ホウ素含有焼結体およびその製造方法
WO2007145071A1 (fr) * 2006-06-12 2007-12-21 Sumitomo Electric Hardmetal Corp. Fritte composite
JP2011212832A (ja) * 2010-03-19 2011-10-27 Mitsubishi Materials Corp 立方晶窒化ほう素基超高圧焼結材料製切削工具

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10954165B2 (en) 2016-04-11 2021-03-23 Iljin Diamond Co., Ltd. Polycrystalline cubic boron nitride and method for preparing same
WO2017204152A1 (fr) * 2016-05-23 2017-11-30 三菱マテリアル株式会社 Outil de coupe fait d'un corps fritté en nitrure de bore cubique
JPWO2017204152A1 (ja) * 2016-05-23 2019-05-16 三菱マテリアル株式会社 立方晶窒化硼素焼結体切削工具
US11130713B2 (en) 2016-05-23 2021-09-28 Mitsubishi Materials Corporation Cubic boron nitride sintered material cutting tool
GB2560642A (en) * 2017-03-15 2018-09-19 Element Six Uk Ltd Sintered polycrystalline cubic boron nitride material
GB2560642B (en) * 2017-03-15 2020-06-17 Element Six Uk Ltd Sintered polycrystalline cubic boron nitride material
US11396482B2 (en) * 2018-09-19 2022-07-26 Sumitomo Electric Industries, Ltd. Cubic boron nitride sintered material, cutting tool including cubic boron nitride sintered material, and method of producing cubic boron nitride sintered material

Similar Documents

Publication Publication Date Title
JP6650106B2 (ja) 立方晶窒化ほう素基焼結体および立方晶窒化ほう素基焼結体製切削工具
JP5305056B1 (ja) 立方晶窒化ほう素基焼結体製切削工具
US9499441B2 (en) Cutting tool made of cubic boron nitride-based sintered material
WO2016084929A1 (fr) Objet fritté à base de nitrure de bore cubique et outil coupant constitué d'un objet fritté à base de nitrure de bore cubique
JP6343888B2 (ja) 耐欠損性にすぐれた立方晶窒化硼素焼結体切削工具
WO2015147249A1 (fr) Outil de coupe à corps fritté en nitrure de bore cubique
JP5988164B2 (ja) 立方晶窒化ほう素基焼結材料製切削工具
JP6032409B2 (ja) 立方晶窒化ほう素基超高圧焼結体を工具基体とする切削工具、表面被覆切削工具
JP6826326B2 (ja) 立方晶窒化硼素焼結体切削工具
JP5892423B2 (ja) 靭性にすぐれたｃＢＮ焼結体切削工具
JP6198142B2 (ja) 立方晶窒化ホウ素基超高圧焼結材料製切削工具
JP6731185B2 (ja) 立方晶窒化ほう素基焼結体および立方晶窒化ほう素基焼結体製切削工具
JP6098882B2 (ja) 耐欠損性にすぐれた立方晶窒化硼素焼結体切削工具
JP6853439B2 (ja) 掘削チップ、掘削工具、および掘削チップの製造方法
JP5804448B2 (ja) 立方晶窒化ほう素基超高圧焼結体およびこれを工具基体とする切削工具、表面被覆切削工具
WO2019177094A1 (fr) Compact fritté de cbn et outil de coupe
JPWO2020175598A1 (ja) ｃＢＮ焼結体および切削工具
JP2022142894A (ja) ｃＢＮ焼結体
JP2020001990A (ja) ｃＢＮ焼結体および切削工具

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15864025

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20177014209

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 15529918

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE

REEP Request for entry into the european phase

Ref document number: 2015864025

Country of ref document: EP