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CN-117396430-B - Diamond polycrystal and tool provided with same

CN117396430BCN 117396430 BCN117396430 BCN 117396430BCN-117396430-B

Abstract

A diamond polycrystal comprising diamond grains, wherein the content of the diamond grains is more than 99% by volume relative to the diamond polycrystal, the median diameter d50 of the diamond grains is 10nm or more and 200nm or less, and the dislocation density of the diamond grains is 0.1×10 15 m ‑2 or more and less than 2.0×10 15 m ‑2 .

Inventors

  • SHI TIANXIONG
  • MATSUKAWA MICHIKO
  • KUKINO SATORU

Assignees

  • 住友电工硬质合金株式会社

Dates

Publication Date
20260505
Application Date
20210611

Claims (8)

  1. 1. A diamond polycrystal comprising diamond particles, wherein, The content of the diamond particles is greater than 99% by volume relative to the diamond polycrystal, The diamond particles have a median diameter d50 of 10nm to 200nm, The dislocation density of the diamond particles is 0.1×10 15 m -2 or more and less than 2.0×10 15 m -2 .
  2. 2. The diamond polycrystalline body of claim 1, wherein the dislocation density of the diamond particles is 0.1 x 10 15 m -2 or more and 1.0 x 10 15 m -2 or less.
  3. 3. The diamond polycrystal according to claim 1 or 2, wherein the diamond particles have a median particle diameter d50 of 10nm or more and 100nm or less.
  4. 4. The diamond polycrystal according to claim 1 or 2, wherein, The diamond polycrystalline body further comprises boron, The boron content is 0.01 mass% or more and 1 mass% or less relative to the diamond polycrystal.
  5. 5. The diamond polycrystal according to claim 1 or 2, wherein the knoop hardness at normal temperature is 80GPa or more.
  6. 6. The diamond polycrystal according to claim 1 or 2, wherein a content of at least one metal element selected from the group consisting of group iv elements, group v elements, iron, aluminum, silicon, cobalt and nickel of the periodic table is less than 1% by volume.
  7. 7. The diamond polycrystal according to claim 1 or 2, wherein a content of at least one kind of unavoidable impurities selected from the group consisting of hydrogen, oxygen, nitrogen, alkali metal elements and alkaline earth metal elements is less than 0.1% by volume.
  8. 8. A tool, wherein the tool is provided with the diamond polycrystalline body of any one of claims 1 to 7.

Description

Diamond polycrystal and tool provided with same Technical Field The present disclosure relates to diamond polycrystalline bodies and tools provided with diamond polycrystalline bodies. Background Diamond polycrystal has excellent hardness and does not have directionality and cleavage of hardness, and therefore is widely used for tools such as cutting tools, trimmers, and dies, and excavating bits. Conventional diamond polycrystalline bodies are obtained by sintering diamond powder as a raw material together with a sintering aid or a binder under high pressure and high temperature (generally, the pressure is about 5 to 8gpa and the temperature is about 1300 to 2200 ℃) under conditions in which diamond is thermodynamically stable. As the sintering aid, iron group metals such as Fe, co, and Ni, carbonates such as CaCO 3, and the like can be used. As the bonding material, ceramics such as SiC can be used. The diamond polycrystalline body obtained by the above method contains a sintering aid or a bonding material. The sintering aid and the binder may cause a decrease in mechanical properties such as hardness and strength of the diamond polycrystal or in heat resistance. Also known are diamond polycrystalline bodies from which a sintering aid is removed by acid treatment, and diamond polycrystalline bodies having excellent heat resistance, which use heat-resistant SiC as a binder. However, the diamond polycrystal has low hardness and strength, and is insufficient in mechanical properties as a tool material. On the other hand, non-diamond carbon materials such as graphite, glassy carbon, amorphous carbon, onion carbon, and the like can be directly converted into diamond at ultrahigh pressure and high temperature without using a sintering aid or the like. Diamond polycrystal is obtained by sintering while directly converting from non-diamond phase to diamond phase (international publication No. 2005/065809 (patent document 1), h.sumiya et al, japanese Journal ofApplied Physics 48 (2009) 120206 (non-patent document 1)). Prior art literature Patent literature Patent document 1 International publication No. 2005/065809 Non-patent literature Non-patent document 1, H.Sumiya et al, japanese Journal ofApplied Physics, 48 (2009) 120206 Disclosure of Invention The diamond polycrystalline body of the present disclosure is a diamond polycrystalline body comprising diamond particles, wherein, The content of the diamond particles is greater than 99% by volume relative to the diamond polycrystal, The diamond particles have a median diameter d50 of 10nm to 200nm, The dislocation density of the diamond particles is 0.1×10 15m-2 or more and less than 2.0×10 15m-2. The tool of the present disclosure is provided with the diamond polycrystal described above. Drawings Fig. 1 is a phase equilibrium diagram of carbon. Detailed Description [ Problem to be solved by the present disclosure ] In recent years, cutting processing with higher efficiency (for example, a high feed rate) has been demanded, and further improvement in performance (for example, improvement in thermal conductivity, improvement in hardness, and the like) of diamond polycrystal has been desired. The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a diamond polycrystal having excellent thermal conductivity and a tool provided with the diamond polycrystal. [ Effect of the present disclosure ] According to the present disclosure, a diamond polycrystal having excellent thermal conductivity and a tool provided with the diamond polycrystal can be provided. [ Description of embodiments of the present disclosure ] First, embodiments of the present disclosure will be described. [1] One embodiment of the present disclosure relates to a diamond polycrystalline body comprising diamond particles, wherein, The content of the diamond particles is more than 99% by volume relative to the diamond polycrystal, The diamond particles have a median diameter d50 of 10nm to 200nm, The dislocation density of the diamond particles is 0.1X10 15m-2 or more and less than 2.0X10 15m-2. The diamond polycrystal has a low dislocation density of diamond particles, and thus has an improved thermal conductivity. That is, the diamond polycrystal has excellent thermal conductivity. [2] Preferably, the dislocation density of the diamond particles is 0.1X10 15m-2 or more and 1.0X10 15m-2 or less. By defining the above, a diamond polycrystal having more excellent thermal conductivity is formed. [3] Preferably, the median diameter d50 of the diamond particles is 10nm or more and 100nm or less. By such a definition, a diamond polycrystal excellent in hardness in addition to excellent in thermal conductivity is formed. [4] Preferably, the diamond polycrystal further contains boron, and the content of boron is 0.01 mass% or more and 1 mass% or less with respect to the diamond polycrystal. By defining the above, a diamond polycrystal having slidability and co