Cutting element having stress reduced interface

• US 8,322,467 B2
• Filed: 10/04/2007
• Issued: 12/04/2012
• Est. Priority Date: 10/04/2007
• Status: Expired due to Fees

• Current Assignee: Smith International Incorporated (SLB)
• Original Assignee: Smith International Incorporated (SLB)
• Inventors: Shen, Yuelin, Zhang, John (Youhe)
• Primary Examiner(s): Thompson, Kenneth L
• Assistant Examiner(s): SAYRE, JAMES G
• Application Number:
  US11/867,611
• Publication Number:
  US 20090090562A1
• Time in Patent Office: 1,888 Days
• Field of Search: 175/426, 175/431
• US Class Current: 175/434
• CPC Class Codes: B22F 2003/245 Making recesses, grooves etc on the surface by removing material
• CPC Class Codes: B22F 2005/001 Cutting tools, earth boring or grinding tool other than table ware
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 7/062 involving the connection or repairing of preformed parts
• CPC Class Codes: C22C 26/00 Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
• CPC Class Codes: C22C 29/08 based on tungsten carbide
• CPC Class Codes: E21B 10/5735 Interface between the substrate and the cutting element

Abstract

Cutting elements include an ultra-hard body, e.g., comprising diamond, that is attached to substrate, e.g., comprising a cermet. An interface exists between the body and the substrate, and an angle of departure as measured between the interface and a free edge of the cutting element within one or both of the body and substrate, is less than about 90 degrees to provide a desired stress reduction along the interface. The angle of departure can be from about 3 to 87 degrees. The desired reduced angle of departure is provided by a surface feature disposed along an outer side surface of the cutting element adjacent a free edge of the interface. The surface feature can in the form of a groove disposed circumferentially around the body and/or substrate outer side surface, that is configured to provide the desired reduced angle of departure within the body and/or substrate.

Claims

1. A bit for drilling subterranean formations, the bit comprising:

a body; and

a plurality of cutting elements disposed onto the bit and comprising;

an ultra-hard body formed from a material selected from the group consisting of diamond, polycrystalline diamond, thermally stable polycrystalline diamond, cubic boron nitride, polycrystalline cubic boron nitride, and combinations thereof; and

a substrate attached to the ultra-hard body and being formed from a material having different mechanical or thermal properties than that of the ultra-hard body;

wherein an interface exists between the body and the substrate, and wherein the cutting element has an angle of departure as measured inside the cutting element between the interface and an outer side surface feature of both the body and substrate adjacent the interface that is less than about 90 degrees, and wherein the outer side surface feature of the body is exposed and free to contact a subterranean formation being drilled when the bit is placed into use.

2. The bit as recited in claim 1 wherein an outer side surface of the body is contoured adjacent the interface to provide the angle of departure within the body of less than about 90 degrees.

3. The bit as recited in claim 2 wherein an outer side surface of the substrate is contoured adjacent the interface to provide the angle of departure within the substrate of less than about 90 degrees.

4. The bit as recited in claim 1 wherein an outer side surface of the substrate is contoured adjacent the interface to provide the angle of departure within the substrate of less than about 90 degrees.

5. The bit as recited in claim 1 wherein the outer side surface features are grooves disposed within the cutting element and positioned circumferentially therearound.

6. The bit as recited in claim 1 wherein the angle of departure is in the range of from about 45 to 75 degrees.

10. The bit as recited in claim 1 wherein the interface is substantially linear extending between the body and substrate to an outside side surface of the cutting element.

7. A bit for drilling subterranean formations comprising:

a body and a number of blades projecting outwardly from the body, wherein the blades include one or more cutting elements attached thereto, wherein the cutting elements comprise;

an ultra-hard body formed from a material selected from the group consisting of diamond, polycrystalline diamond, thermally stable polycrystalline diamond, cubic boron nitride, polycrystalline cubic boron nitride, and combinations thereof;

a substrate that is attached to the ultra-hard body and that is formed from a material having different mechanical or thermal properties than that of the ultra-hard body;

wherein an interface exists between the body and the substrate, and wherein the cutting element has an angle of departure as measured within the cutting element between the interface and a free edge of the cutting element in both of the body and substrate that is less than about 90 degrees; and

wherein the angle of departure is provided by a surface feature positioned along an outer side surface of both of the body and the substrate adjacent the interface, and wherein the surface feature on the body is exposed and free to contact a subterranean formation being drilled when placed into use.

11. The bit as recited in claim 7 wherein the interface is substantially linear extending between the body and substrate to an outside side surface of the cutting element.

8. A cutting element comprising:

an ultra-hard body formed from a material selected from the group consisting of diamond, polycrystalline diamond, thermally stable polycrystalline diamond, cubic boron nitride, polycrystalline cubic boron nitride, and combinations thereof;

a substrate attached to the ultra-hard body and formed from a material having different mechanical or thermal properties than that of the ultra-hard body;

wherein an interface exists between the body and the substrate, and wherein the ultra-hard body has an angle of departure as measured within the cutting element between the interface and an outer side surface of the ultra-hard body adjacent the interface that is less than about 90 degrees; and

wherein the substrate has an angle of departure as measured within the cutting element between the interface and an outer side surface of the substrate adjacent the interface that is less than about 90 degrees.

12. The cutting element as recited in claim 8 wherein the interface is substantially linear extending between the body and substrate to an outside side surface of the cutting element.

9. A bit for drilling subterranean formations comprising:

a body and a number of blades projecting outwardly from the body, wherein the blades include one or more cutting elements attached thereto, wherein the cutting elements comprise;

an ultra-hard body formed from a material selected from the group consisting of diamond, polycrystalline diamond, thermally stable polycrystalline diamond, cubic boron nitride, polycrystalline cubic boron nitride, and combinations thereof;

a substrate that is attached to the ultra-hard body and that is formed from a material having different mechanical or thermal properties than that of the ultra-hard body;

wherein an interface exists between the ultra-hard body and the substrate, and wherein the cutting element has an angle of departure as measured within the cutting element between the interface and an outer side surface of the ultra-hard body adjacent the interface that is less than about 90 degrees; and

wherein the cutting element has an angle of departure as measured within the cutting element between the interface and an outer side surface of the substrate adjacent the interface that is less than about 90 degrees.

13. The bit as recited in claim 9 wherein the interface is substantially linear extending between the body and substrate to an outside side surface of the cutting element.