Claims
- 1. A method of manufacture of an earth boring drill bit, the drill bit comprising a bit body and a polycrystalline diamond element, the polycrystalline diamond element comprising bonded diamond crystals and a catalyzing material, a working surface on the polycrystalline diamond element; comprising the steps of treating the polycrystalline diamond element to render a second volume adjacent to the working surface thereof substantially free of the catalyzing material to a depth of at least about 0.1 mm from the working surface while permitting the catalyzing material to remain in a first volume of the polycrystalline diamond element, and mounting the polycrystalline diamond element on the bit body.
- 2. The method of claim 1, wherein the second volume is rendered substantially free of catalyzing material by leaching the catalyzing material from the second volume.
- 3. The method of claim 1, wherein the second volume is rendered substantially free of catalyzing material by converting the catalyzing material in the second volume to a form in which it does not have a catalyzing effect.
- 4. The method of claim 1, wherein the second volume is rendered substantially free of catalyzing material by reacting the catalyzing material to form a substance which does not have a catalyzing effect.
- 5. The method of claim 1, wherein the second volume is rendered substantially free of catalyzing material by electrical discharge.
- 6. The method of claim 1, wherein the second volume is rendered substantially free of catalyzing material using a galvanic process.
- 7. The method of claim 1, wherein the second volume is rendered substantially free of catalyzing material using an evaporation process.
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of pending U.S. patent application Ser. No. 09/682,042 filed on Jul. 13, 2001, by Nigel D. Griffin and Peter R. Hughes, hereby incorporated by reference herein, which claims priority from U.S. Provisional Patent Application No. 60/234,075 filed Sep. 20, 2000, and from U.S. Provisional Patent Application No. 60/281,054 filed Apr. 2, 2001.
Provisional Applications (2)
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Number |
Date |
Country |
|
60234075 |
Sep 2000 |
US |
|
60281054 |
Apr 2001 |
US |
Divisions (1)
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Number |
Date |
Country |
Parent |
09682042 |
Jul 2001 |
US |
Child |
10065604 |
Nov 2002 |
US |