Selectively Leached Cutter

• US 20140166371A1
• Filed: 04/20/2012
• Published: 06/19/2014
• Est. Priority Date: 04/20/2011
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Whittaker, Malcolm E.
• Granted Patent: US 9,488,011 B2
• Time in Patent Office: Days
• US Class Current: 175/432
• CPC Class Codes: B22F 2005/001 Cutting tools, earth boring or grinding tool other than table ware
• CPC Class Codes: B22F 7/08 with one or more parts not made from powder B22F7/062 takes precedence
• CPC Class Codes: B24D 3/10 for porous or cellular structure, e.g. for use with diamonds as abrasives
• CPC Class Codes: C22C 1/00 Making non-ferrous alloys by electrothermic methods C22B4/00; by electrolysis C25C1/24, C25C3/36
• CPC Class Codes: C22C 19/07 based on cobalt
• 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 10/567 with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
• CPC Class Codes: E21B 10/5676 having a cutting face with different segments, e.g. mosaic-type inserts
• CPC Class Codes: E21B 10/573 characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element

Abstract

A method of manufacturing a polycrystalline diamond (PCD) cutting element used as drill bit cutting elements (10) is disclosed. The method comprises leaching a PCD body formed from diamond particles (202) using a binder-catalyzing material so as to remove substantially all of the binder-catalyzing material from portions of a cutting surface of the PCD body. A portion (24) of the cutting surface is identified as a cutting area which, in use of the cutting element to cut material, is heated by the cutting action of the cutting element. Leaching of the PCD body includes performing a relatively deep leach in the portion of the cutting surface identified as the cutting area and performing a relatively shallow leach in at least the portion (26) of the cutting surface surrounding the identified cutting area.

Claims

1-71. -71. (canceled)

72. A method of manufacturing a polycrystalline diamond (PCD) cutting element comprising:

identifying a portion of a cutting surface of a PCD body in a PCD cutting element as a cutting area which, during use of the PCD cutting element, is heated by the cutting action of the cutting element;

a

leaching the PCD body so as to remove substantially all of a binder-catalyzing material from the cutting area with a relatively deep leach; and

leaching the PCD body so as to remove substantially all of the binder-catalyzing material from at least a portion of the cutting surface surrounding the cutting area with a relatively shallow leach.

73. The method of claim 72, wherein the portion of the cutting surface surrounding the cutting area is masked while leaching the cutting area with a relatively deep leach.

74. The method of claim 72, wherein leaching with a relatively deep leach occurs prior to leaching with a relatively shallow leach.

75. The method of claim 72, comprising leaching the PCD body so as to remove substantially all of the binder-catalyzing material from substantially all of the cutting surface other than the cutting area with a relatively shallow leach.

76. The method of claim 72, wherein substantially no leaching occurs at a central portion of the cutting surface.

77. The method of claim 72, comprising leaching a side surface of the PCD body which extends from the cutting surface with a relatively shallow leach.

78. The method of claim 72, wherein the PCD body is substantially cylindrical and the cutting surface is one of the end faces of the cylinder, and wherein the cutting area includes at least a portion of a cutting edge that extends around the cutting surface, between the cutting surface and a cylindrical side wall.

79. The method of claim 78, wherein the cutting edge is a chamfered edge between the cutting surface and the side wall.

80. The method of claim 72, wherein identifying the cutting area includes identifying multiple areas which independently act as the cutting area in dependence on the orientation of the PCD cutting element in use.

81. The method of claim 80, wherein leaching with a relatively deep leach includes simultaneously leaching all of the multiple cutting areas.

82. The method of claim 80, wherein two or more of the multiple cutting areas are substantially identical and disposed with rotational symmetry about an axis of the PCD body, such that, in use of the cutting element held in a cutting tool, the PCD body can be rotated about the axis after a first of the two or three or more areas has independently acted as a cutting area and become worn down, so as to bring the worn first cutting area out of cutting orientation and to bring another of the two or three or more areas into the cutting orientation.

83. The method of claim 72, wherein the cutting element includes one or more indicia to indicate the position of the cutting area.

84. The method of claim 78, wherein the cutting area includes substantially all of the cutting edge, which extends substantially entirely around the cutting surface.

85. The method of claim 72, comprising leaching to different depths in a transition region between the relatively deep-leached portions and the relatively shallow-leached portions, to obtain a desired leaching-depth profile.

86. The method of claim 72, wherein the binder-catalyzing material is removed from the cutting area to a depth of not less than about 0.15 mm.

87. The method of claim 72, wherein the binder-catalyzing material is removed from the portion of the cutting surface surrounding the cutting area to a depth of not less than about 0.01 mm and not more than about 0.12 mm.

88. A polycrystalline diamond (PCD) cutting element comprising:

a PCD body exhibiting a cutting face and defining a cutting edge around at least a portion of the cutting face,

wherein the PCD body comprises a diamond matrix of intercrystalline bonded diamond particles defining interstitial regions containing a binder-catalyzing material,

wherein a first region at a surface of the diamond matrix comprises substantially no binder-catalyzing material to a depth of not less than about 0.15 mm, said first region including at least a portion of said cutting edge, and

wherein a second region at the surface of the diamond matrix surrounding said first region contains substantially no binder-catalyzing material to a depth of not less than about 0.01 mm and not more than about 0.12 mm.

89. The PCD cutting element of claim 88, wherein the second region at the surface of the diamond matrix includes at least a portion of a side surface of the PCD body, which side surface extends from the cutting face and meets the cutting face at the cutting edge.

90. An earth-boring drill bit comprising a diamond (PCD) cutting element comprising:

a PCD body exhibiting a cutting face and defining a cutting edge around at least a portion of the cutting face,

wherein the PCD body comprises a diamond matrix of intercrystalline bonded diamond particles defining interstitial regions containing a binder-catalyzing material,

wherein a first region at a surface of the diamond matrix comprises substantially no binder-catalyzing material to a depth of not less than about 0.15 mm, said first region including at least a portion of said cutting edge, and

wherein a second region at the surface of the diamond matrix surrounding said first region contains substantially no binder-catalyzing material to a depth of not less than about 0.01 mm and not more than about 0.12 mm.

91. The earth-boring drill bit of claim 90, wherein the second region at the surface of the diamond matrix includes at least a portion of a side surface of the PCD body, which side surface extends from the cutting face and meets the cutting face at the cutting edge.