Semiconductive polycrystalline diamond
AssigneeSmith International, Inc.
InventorStewart Middlemiss
Life of this patent
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Abstract
An ultra-hard semiconductive polycrystalline diamond (PCD) material formed with semiconductive diamond particles doped with Li, Be or Al and/or insulative diamond particles having semiconductive surfaces, tools incorporating the same, and methods for forming the same, are provided. The ultra-hard PCD material may be formed using a layer of insulative diamond grit feedstock that includes additives therein, then sintering to convert a plurality of the diamond crystals to include a semiconductive surface. In another embodiment, the ultra-hard PCD material is formed by sintering semiconductive diamond grit feedstock consisting of diamond crystals doped with Li, Al or Be. The ultra-hard semiconductive PCD cutting layer exhibits increased cuttability, especially in EDM and EDG cutting operations.
Claims36
A method for forming a cutting element comprising:
- providing a layer of diamond powder comprising non-conductive diamond crystals and an additive;
- and
- converting said non-conductive diamond crystals and said additive to a polycrystalline diamond layer, said polycrystalline diamond layer being a solid semiconductor material.
A method for forming a cutting element comprising:
- providing a layer of diamond grit feedstock including diamond crystals doped with at least one of Be, Li and Al;
- and
- sintering to convert said layer of diamond grit feedstock to a polycrystalline diamond layer, said polycrystalline diamond layer being a solid semiconductor material.
A polycrystalline diamond material comprising diamond crystals doped with a material selected from the group consisting of Be, Li and Al.
A polycrystalline diamond material comprising Type I diamond crystals therein, a plurality of said Type I diamond crystals having semiconductive surface layers.
A drill bit comprising a cutting element comprising a substrate and a polycrystalline diamond layer over said substrate, said polycrystalline diamond layer including Type I diamond crystals therein, a plurality of said Type I diamond crystals having semiconductive surface layers.
A drill bit comprising a cutting element comprising a substrate and a polycrystalline diamond layer over said substrate, said polycrystalline diamond layer including diamond crystals doped with an additive selected from the group consisting of lithium, beryllium and aluminum.
Dependencies are inferred from the claim text.