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Single crystal fine diamond powder having narrow particle size distribution and its prodn. method

A diamond particle and temperature range technology, which is applied in the field of diamond grinding powder and composites made of materials, can solve the problems of uneven processing surface, serious wear, difficult abrasive, etc.

Inactive Publication Date: 2003-10-08
2 KANAGAWA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the difference in hardness of the head material, the abrasive product preferentially grinds the softest metal film relative to other parts, which inevitably results in uneven or rough processing surfaces
[0012] This causes the problem of Pole Tip Recess (PTR): The pole tip is the part made of thin metal film that wears more and ends up behind the rest of the air bearing surface made of ceramic material causing media and Increased Magnetic Gap Between Effective Flight Altitudes
[0016] When using traditional single crystal diamond abrasives, there is a tendency: as the nominal particle size decreases, the number of adhered particles will increase, so it is difficult for this type of abrasive to suppress both adhered particles and the above-mentioned Solutions for extremely sharp depressions

Method used

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  • Single crystal fine diamond powder having narrow particle size distribution and its prodn. method
  • Single crystal fine diamond powder having narrow particle size distribution and its prodn. method
  • Single crystal fine diamond powder having narrow particle size distribution and its prodn. method

Examples

Experimental program
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Effect test

Embodiment 1

[0031] Micro-grinding and precise sieving of single-crystal diamond particles (TOMEI DIAMOND IRM grade) with a nominal particle size of 2-6 μm.

[0032]For the pulverization step, a steel ball mill jar with a diameter and length of 250 nm was used. Pack 300 grams of the above-mentioned raw diamond powder, and 20kg of steel balls with a diameter of 6nm, and the ball mill jar was operated at 80 R.P.M. for 120 hours. The pulverized powder is taken out from the tank and put into 10HCl-1HNO 3 In the mixed acid solution, the iron content is removed by dissolution, and then rinsed thoroughly with water.

[0033] For the elutriation process, a row of serially connected pipes was used, each comprising a 20 cm long straight cylindrical section, the cross section of the pipe used for the first step was 2500 cm 2 , the other for the second step is 5000cm 2 . This pipe system contained 1 kg of crushed diamond and was subjected to elutriation while passing 120 liters of ion-exchanged wa...

Embodiment 2

[0038] TOMEI DIAMOND MD100 (trade name) diamond powder, which is a grinding product obtained by elutriation and used exclusively for precision machining processes, was used as a raw material.

[0039] This milled powder has the following MICROTRAC particle size distribution with a D50 value at 103.9 nm and a cumulative result of 19.75% of particles up to channel 27 (72.3 nm) having a particle size corresponding to 70% of the above D50 value. That is, the raw material contained about 20% of fractions having a particle size smaller than 70 nm.

[0040] 1 kg of the diamond powder was charged into the elutriation system arranged in the same manner as in Example 1, and sieved while passing through ion-exchanged water at a rate of 0.5 cc per minute.

[0041] Due to re-sieving by this method, the collected powder had a MICROTRAC D50 value of 107.4, which is practically the same average particle size as the original powder. However, equivalent to 70% d D50 The value, the frequency i...

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Abstract

Provided are single-crystal micro-diamond particle groups with a narrow particle size range used as abrasives for precision machining and a manufacturing method thereof. The particles are prepared by the following method: preparing single crystal diamond particles under ultra-high pressure static compression, pulverizing them into very small particles, and performing precise sieving. The particle population is characterized by having the following particle size parameters: a D50 particle size of 120 nm or less, and a ratio of D10 and D90 to D50 of 50% or more, and 200% or less, respectively. The particle group used as abrasive material can effectively process a variety of parts, including general hard materials and composites containing different hardness components, especially ultra-high precision machining with low PTR values.

Description

technical field [0001] The present invention relates to single-crystal tiny diamond particles in a narrow particle size range, in particular to diamond grinding powder, which is especially suitable for high-hardness substances, and composites made of materials with different hardness, such as ultra-precision machining of thin-film magnetic head blanks (blank) . Background technique [0002] With the recent development of machining technology, the demand for diamond abrasive powder is increasingly turning to finer particles. In this way, submicron particle size, or particles with a diameter of less than one micron, are being used more and more in many industrial fields. At the same time, the requirements for performance, especially the size distribution of fine particles, are also increasing year by year. [0003] The preparation of diamond particles usually involves converting non-diamond carbon into diamond single crystals using static ultra-high pressure methods, which ar...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B03B5/62
CPCB03B5/62C09K3/1409C30B29/04C01P2004/64C01P2004/62C01P2004/51
Inventor 山中博大岛龙司佐藤良一齐藤信之石塚博
Owner 2 KANAGAWA