Method for making super-hard constructions

Patent metadata

Field	Value
Publication number	US-9643334-B2
Application number	US-201314394752-A
Country	US
Kind code	B2
Filing date	Apr 17, 2013
Priority date	Apr 20, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A method of making a construction comprising a polycrystalline super-hard structure joined to a side surface of an elongate substrate. The method includes: providing a vessel configured for an ultra-high pressure, high temperature furnace, the vessel having an elongate cavity for containing a pre-sinter assembly and defining a longitudinal axis, the cavity having opposite ends connected by a cavity wall. The pre-sinter assembly comprises the substrate, an aggregation comprising a plurality of super-hard grains arranged over at least a part of the side surface of the substrate, and a spacer structure configured for spacing the substrate apart from the cavity wall. The spacer structure comprises material having a Young's modulus of at least 300 GPa. The method further includes inserting the pre-sinter assembly into the cavity, the substrate being substantially longitudinally aligned and the spacer structure arranged between the side surface of the substrate and the cavity wall; applying a force to the pre-sinter assembly and heating it to a temperature, the force being sufficient to generate a pressure within the vessel for sintering the aggregation at the temperature, and providing the construction.

First claim

The invention claimed is:

1. A method of making a construction comprising a polycrystalline super-hard structure joined to a side surface of an elongate substrate; the method including: providing a vessel configured for an ultra-high pressure of at least 4 GPa, high temperature furnace configured to reach a temperature of at least 1000° C., the vessel having an elongate cavity for containing a pre-sinter assembly and defining a longitudinal axis, the cavity having opposite ends connected by a cavity wall; the pre-sinter assembly comprising the substrate, an aggregation comprising a plurality of super-hard grains arranged over at least a part of the side surface of the substrate, and an annular spacer structure configured for spacing the substrate apart from the cavity wall; the spacer structure comprising material having a Young's modulus of at least 300 GPa; the method further including inserting the pre-sinter assembly into the cavity, the substrate being substantially longitudinally aligned and the spacer structure arranged between the side surface of the substrate and the cavity wall; applying a force to the pre-sinter assembly and heating it to a temperature, the force being sufficient to generate a pressure within the vessel for sintering the aggregation at the temperature, and providing the construction, wherein the spacer and the polycrystalline super-hard structure comprise different materials.

2. A method as claimed in claim 1 , in which the substrate comprises the spacer structure extending laterally from an elongate core structure of the substrate.

3. A method as claimed in claim 1 , in which the spacer structure abuts the substrate.

4. A method as claimed in claim 1 , in which the force is applied longitudinally or tri-axially to the pre-sinter assembly.

5. A method as claimed in claim 1 , in which the substrate comprises an elongate core structure and an end cap defining a proximate end surface of the substrate, the end cap extending laterally beyond the core structure.

6. A method as claimed in claim 1 , in which the spacer structure abuts the cavity wall.

7. A method as claimed in claim 1 , the method including using more than one spacer structure, each arranged at a different respective longitudinal position along the substrate.

8. A method as claimed in claim 1 , in which the substrate is rotationally symmetric about a central longitudinal axis.

9. A method as claimed in claim 1 , in which the spacer structure comprises material having a Young's modulus of at least 300 GPa at a temperature of at least 1,000 degrees centigrade.

10. A method as claimed in claim 1 , in which the spacer structure comprises cemented tungsten carbide.

11. A method as claimed in claim 1 , in which the spacer structure comprises ceramic material.

12. A method as claimed in claim 1 , in which the spacer structure comprises nickel based super-alloy material.

13. A method as claimed in claim 1 , in which the spacer structure comprises super-hard material.

14. A method as claimed in claim 1 , in which the vessel comprises pyrophyllite, mullite, kyonite, kaolinite, salt or ceramic material.

15. A method as claimed in claim 1 , in which the super-hard grains comprise natural or synthetic diamond material, or cubic boron nitride (cBN) material.

16. A method as claimed in claim 1 , in which the polycrystalline super-hard structure comprises polycrystalline diamond (PCD) material, polycrystalline cubic boron nitride (PCBN) material, silicon carbide bonded diamond (SCD) material or cemented carbide material comprising super-hard grains.

17. A method as claimed in claim 1 , in which the construction is for a blank body from which a rotary machine tool cutter element can be manufactured.

18. A method as claimed in claim 1 , in which the aggregation comprises super-hard grains and binder material binding the grains together.

19. A method as claimed in claim 1 , in which the aggregation comprises a plurality of filaments, foils or sheets comprising the super-hard grains.

20. A method as claimed in claim 1 , including providing granules comprising the super-hard grains, and combining and compacting the granules against the substrate.

21. A method as claimed in claim 1 , in which the aggregation comprises an extruded body comprising the super-hard grains.

22. A method as claimed in claim 1 , in which the aggregation is spaced apart from at least one end of the substrate by at least 1 mm.

23. A method as claimed in claim 1 , in which the aggregation is spaced apart from at least one end of the substrate by the spacer structure.

24. A method as claimed in claim 1 , in which the aggregation extends peripherally all the way around at least a part of the substrate.

25. A method as claimed in claim 1 , the method including processing the super-hard structure to provide a cutting edge.

26. A method as claimed in claim 1 , the method including brazing an end of the construction to a tool carrier.

Assignees

• Element Six Abrasives Sa
• Element Six Ltd

Inventors

• Kasonde Maweja
• Choenyane Leshope Joseph
• Radebe Erens Tshepo
• Barry John James

Classifications

• B23C5/10

  Shank-type cutters, i.e. with an integral shaft · CPC title

• B22F3/14 Primary

  simultaneously · CPC title

• C04B35/64

  Burning or sintering processes (C04B33/32 takes precedence {; powder metallurgy B22F}) · CPC title

• C22C26/00

  Alloys containing diamond {or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes} · CPC title

• B23B2226/315

  polycrystalline [PCD] · CPC title