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US5061292A Expired / Lapsed US ⏱️ 0.0 years remaining

Diamond abrasive and method for producing the same

Assignee: Ishizuka Research Institute Ltd
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Filing: 1989-07-13
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Granted: 1991-10-29
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Expires: 2009-07-13
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Abstract

Abstract Diamond abrasive comprising a mass of idiomorphic crystal grits which each have an irregular shaped core of diamond formed under pressure where diamond is thermodynamically favored phase, and a growth layer of diamond and/or diamond-like carbon formed over said core by chemical vapor deposition.

Inventors

  • 👤 Chia-Fu Chen
  • 👤 Ensei Ko
  • 👤 Hiroshi Ishizuka
  • 👤 Satoru Hosomi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 18:53
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/22; C23C16/26; B; B24; B24D; B24D3/00; B24D3/005; B24D3/007; C09; C09K; C09K3/00; C09K3/14; C09K3/1436

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 56 words
Abrasive grits comprising a mass of idiomorphic diamond crystals which each have an irregular shaped core of diamond formed under a pressure at which diamond is the thermodynamicaly favored phase of carbon, and a growth layer of diamond-like carbon, which has at least in part a diamond structure, formed over said core by chemical vapor deposition.
Claim 2
Dependent Claim 56 words
Abrasive grits comprising a mass of idiomorphic diamond crystals which each have an irregular shaped core of diamond formed under a pressure at which diamond is the thermodynamicaly favored phase of carbon, and a growth layer of diamond-like carbon, which has at least in part a diamond structure, formed over said core by chemical vapor deposition.
Claim 3
Dependent Claim 26 words
The diamond abrasive as claimed in claim 1, in which said grits, as measured in average, exhibit an overall size not greater than twice the core.
Claim 4
Dependent Claim 18 words
The diamond abrasive as claimed in claim 2, in which said grits are not greater than 60 microns.
Claim 5
Dependent Claim 32 words
The diamond abrasive as claimed in claim 1, in which said grits exhibit a major to minor axial ratio not greater than 1.3 in average when taken perpendicular to the major axis.
Claim 6
Independent Claim 74 words
A method of producing diamond abrasive, comprising: placing as seeds irregular shaped diamond particles from a high pressure process in a controlled gas mixture comprising hydrogen and carbonaceous substance, exciting the gas mixture to be in plasma state, exposing said particles to the plasma thus causing growth of the particles, regulating the growth rate to a level close to the kinetic equilibrium thus imparting idiomorphic shapes, and recovering the grown diamond as abrasive grits.
Claim 7
Independent Claim 74 words
A method of producing diamond abrasive, comprising: placing as seeds irregular shaped diamond particles from a high pressure process in a controlled gas mixture comprising hydrogen and carbonaceous substance, exciting the gas mixture to be in plasma state, exposing said particles to the plasma thus causing growth of the particles, regulating the growth rate to a level close to the kinetic equilibrium thus imparting idiomorphic shapes, and recovering the grown diamond as abrasive grits.
Claim 8
Dependent Claim 25 words
The method as claimed in claim 5, in which said growth rate is a radial increase on the order of a few microns per hour.
Claim 9
Dependent Claim 23 words
The method as claimed in claim 6, in which said growth rate is a radial increase not greater than 5 microns per hour.
Claim 10
Dependent Claim 23 words
The method as claimed in claim 6, in which said growth rate is a radial increase not greater than 3 microns per hour.
Claim 11
Dependent Claim 18 words
The method as claimed in claim 5, in which said seeds exhibit an average size of 20 microns.
Claim 12
Dependent Claim 22 words
The method as claimed in claim 5, in which said grits are recovered before an average size exceeds twice the core size.
Claim 13
Dependent Claim 10 words
Abrasive grits made according to the process of claim 5.

References Cited (Backward Citations)

US4089933A Cited
US4196181A Cited
US4063907A Cited
US4104441A Cited
US4124690A Cited
US4220455A Cited
US4610698A Cited
US4832708A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-10-28 1995-04-29 1995-10-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-10-28 1999-04-29 1999-10-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-10-28 2003-04-29 2003-10-29 $7700.00 Window Closed / Lapsed

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