Support structure for a body of polycrystalline diamond material during leaching

Patent metadata

Field	Value
Publication number	US-10166523-B2
Application number	US-201314758586-A
Country	US
Kind code	B2
Filing date	Dec 23, 2013
Priority date	Dec 31, 2012
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

A support structure (40) for a PCD element (10) comprises a support (42) into which a PCD element (10) is locatable and a sealing element (48) for location in the support structure (40) and configured to protect a non-leached portion of a PCD element (10) during a leaching process. The support (42) is formed from or coated with a polyketone based plastics material.

First claim

The invention claimed is:

1. A method of processing a body of polycrystalline diamond (PCD) material having a non-diamond phase comprising a diamond catalyst/solvent and/or one or more metal carbides, the method comprising:
locating the body of PCD material to be processed in a support formed of or coated with a polyketone based plastics material;
forming a sealing closure between the body PCD material and the support to separate a region of the body of PCD material to be treated from a region not to be treated;
inserting the body of PCD material and support into a leaching vessel, the leaching vessel containing an amount of leaching mixture;
leaching an amount of the diamond catalyst/solvent and/or one or more metal carbides from the PCD material by exposing at least a portion of the PCD material to the leaching mixture; wherein,
the leaching mixture comprises nitric acid diluted in water, the nitric acid comprising between around 2 to 5 wt % in the nitric acid and water mixture, and one or more additional mineral acids.

2. The method of claim 1 , wherein the one or more additional mineral acids comprise one or more of hydrochloric acid, sulphuric acid, phosphoric acid and hydrofluoric acid.

3. The method of claim 1 , wherein the leaching mixture comprises the one or more additional mineral acids at a molar concentration of up to around 7M.

4. The method of claim 1 , wherein the leaching mixture comprises the one or more additional mineral acids at a molar concentration of around 7M.

5. The method of claim 1 , wherein the leaching mixture comprises nitric acid at a molar concentration of up to around 1.3 M.

6. The method of claim 1 , wherein the leaching mixture comprises nitric acid at a molar concentration of between around 0.2 M to around 1.2 M.

7. The method of claim 1 , further comprising heating the leaching mixture to a temperature equal to or greater than the boiling temperature of the leaching mixture during the step of exposing the PCD material to the leaching mixture.

8. The method of claim 1 , wherein the solvent/catalyst comprises cobalt, nickel and/or iron.

9. The method of claim 1 , wherein the step of leaching comprises leaching one or more of a carbide of tungsten, titanium, niobium, tantalum, zirconium, molybdenum, chromium, or vanadium from the PCD material.

Assignees

• Element Six Abrasives Sa
• Element Six Ltd

Inventors

• Scanlon Terry
• Sullivan Desmond Kenneth
• Doyle James
• Redmond James Martin
• Sithebe Humphrey Samkelo Lungisani

Classifications

• B01J3/062

  characterised by the composition of the materials to be processed · CPC title

• B01J19/02 Primary

  Apparatus characterised by being constructed of material selected for its chemically-resistant properties · CPC title

• B01J2203/062

  Diamond · CPC title

• B01J2203/0685

  Crystal sintering · CPC title

• B24D18/00

  Manufacture of grinding tools {or other grinding devices}, e.g. wheels, not otherwise provided for · CPC title