Sweep through process for making polycrystalline compacts

Claim 2

An improved process for making a polycrystalline diamond compact comprising subjecting a mass of diamond particles, which mass is in contact with a source of catalyst for diamond recrysallization, to a high pressure/high temperature process which results in a compact characterized by diamond-to-diamond bonding and containing an interstitial metal phase comprising catalyst; wherein the improvement comprises placing in contact with the mass of diamond particles an additional metal or metal alloy selected from the group consisting of: (a) single metals and non-catalytic alloys of such metal which: (i) have a lower melting point than the catalyst; (ii) do not interfere with the function of the catalyst; and (iii) are miscible with the catalyst; and (b) single metals and non-catalytic alloys of metals as described in (a) above in the form of catalytic alloys with the catalyst, which catalytic alloys do not interfere with the function of the catalyst and at least initially form a catalyst-lean liquid phase during the high pressure/high temperature process.

Claim 3

The improved process of claim 1 wherein the additional metal or metal alloy is mixed with the diamond.

Claim 4

The improved process of claim 1 which further comprises removing substantially all of the metal phase from the compact.

Claim 5

The improved process of claim 1 in which additional metal or metal alloy is selected from the group consisting of single metals and non-catalytic alloys of such metals which: (i) have a lower melting point than the catalyst; (ii) do not interfere with the function of the catalyst; and (iii) are miscible with the catalyst.

Claim 6

The improved process of claim 4 wherein the additional metal or metal alloy is placed between the diamond and the catalyst source.

Claim 7

The improved process of claim 5 in which the additional metal is a single metal which sweeps through the diamond mass ahead of the catalyst.

Claim 8

The improved process of claim 6 wherein the additional metal is selected from the group consisting of copper, tin, aluminum, zinc, magnesium and antimony.

Claim 9

The improved process of claim 7 wherein the additional metal is copper.

Claim 10

The improved process of claim 5 wherein the catalyst source is a mass selected from the group consisting of cemented metal carbide and carbide molding powders wherein at least part of the cementing agent is a catalyst.

Claim 11

The improved process of claim 4 wherein the catalyst source comprises a mass of material containing a catalyst which mass provides lateral support for the diamond particles, and wherein the additional metal or metal alloy is in contact with the particles at an open end of the supporting mass.

Claim 12

The improved process of claim 10 wherein the supporting mass is an annulus of cemented metal carbide or carbide molding powders and wherein at least a part of the cementing agent is a catalyst.

Claim 13

The improved process of claim 1 in which the additional metal or metal alloy is selected from the group consisting of single metals and noncatalytic alloys of such metals which: (i) have a lower melting point than the catalyst; (ii) do not interfere with the function of the catalyst; and (iii) are miscible with the catalyst and wherein said metals and metal alloys are in the form of catalytic alloys with the catalyst, which catalytic alloys do not interfere with the function of the catalyst and at least initially form a catalyst-lean liquid phase during the high pressure/high temperature process.

Claim 14

The improved process of claim 12 wherein the catalytic alloy is selected from the group consisting of alloys of cobalt and copper and alloys of nickel and copper.

Claim 15

The improved process as in claim 12 wherein the catalyst source comprises a mass of material containing a catalyst which mass provides lateral support for the diamond particles, and wherein the catalytic alloy is in contact with the particles at an open end of the supporting mass.

Claim 16

An improved process for making a polycrystalline cubic boron nitride compact comprising subjecting a mass of cubic boron nitride particles, which mass is in contact with a source of sintering catalyst, to a high pressure/high temperature process which results in a compact having at least 70 volume percent cubic boron nitride content and an interstitial metal phase comprising catalyst within the resulting polycrystalline mass; wherein the improvement comprises placing in contact with the mass of cubic boron nitride particles an additional metal or metal alloy selected from the group consisting of: (a) single metals and non-catalytic alloys of such metals which: (i) have a lower melting point than the catalyst; (ii) do not interfere with the function of the catalyst; and (iii) are miscible with the catalyst; and (b) single metals and non-catalytic alloys of metals as described in (a) above in the form of catalytic alloys with the catalyst, which catalytic alloys do not interfere with the function of the catalyst and at least initially form a catalyst-lean liquid phase during the high pressure/high temperature process.

Claim 17

An improved process for making a polycrystalline cubic boron nitride compact comprising subjecting a mass of cubic boron nitride particles, which mass is in contact with a source of sintering catalyst, to a high pressure/high temperature process which results in a compact having at least 70 volume percent cubic boron nitride content and an interstitial metal phase comprising catalyst within the resulting polycrystalline mass; wherein the improvement comprises placing in contact with the mass of cubic boron nitride particles an additional metal or metal alloy selected from the group consisting of: (a) single metals and non-catalytic alloys of such metals which: (i) have a lower melting point than the catalyst; (ii) do not interfere with the function of the catalyst; and (iii) are miscible with the catalyst; and (b) single metals and non-catalytic alloys of metals as described in (a) above in the form of catalytic alloys with the catalyst, which catalytic alloys do not interfere with the function of the catalyst and at least initially form a catalyst-lean liquid phase during the high pressure/high temperature process.

Claim 18

The improved process of claim 15 wherein the additional metal or metal alloy is mixed with the cubic boron nitride.

Claim 19

The improved process of claim 15 which further comprises removing substantially all of the metal phase from the compact.

Claim 20

The improved process of claim 15 in which the additional metal or metal alloy is selected from the group consisting of single metals and noncatalytic alloys of such metals which: (i) have a lower melting point than the catalyst; (ii) do not interfere with the function of the catalyst; and (iii) are miscible with the catalyst.

Claim 21

The improved process of claim 18 wherein the additional metal or metal alloy is placed between the cubic boron nitride and the catalyst source.

Claim 22

The improved process of claim 19 in which the additional metal is a single metal which sweeps through the cubic boron nitride mass ahead of the catalyst.

Claim 23

The improved process of claim 20 wherein the additional metal is selected from the group consisting of copper, tin, aluminum, zinc, magnesium and antimony.

Claim 24

The improved method of claim 21 wherein the additional metal is copper.

Claim 25

The improved method of claim 19 wherein the catalyst source is a mass selected from the group consisting of cemented metal carbide and carbide molding powders wherein at least part of the cementing agent is a catalyst.

Claim 26

The improved process of claim 18 wherein the catalyst source comprises a mass of material containing a catalyst which mass provides lateral support for the cubic boron nitride particles, and wherein the additional metal or metal alloy is in contact with the particles at an open end of the supporting mass.

Claim 27

The improved process of claim 24 wherein the supporting mass is an annulus of cemented metal carbide or carbide molding powders wherein at least part of the cementing agent is a catalyst.

Claim 28

The improved process of claim 15 in which the additional metal or metal alloy is selected from the group consisting of single metals and noncatalytic alloys of such metals which: (i) have a lower melting point than the catalyst; (ii) do not interfere with the function of the catalyst; and (iii) are miscible with the catalyst, and wherein said metals and metal alloys are in the form of catalytic alloys with the catalyst, which catalytic alloys do not interfere with the function of the catalyst and at least initially form a catalyst-lean liquid phase during the high pressure/high temperature process.

Claim 29

The improved process of claim 26 wherein the alloy is selected from the group consisting of alloys of cobalt and copper and alloys of nickel and copper.

Claim 30

The improved process of claim 26 wherein the catalyst source comprises a mass of material containing a catalyst which mass provides lateral support for the cubic boron nitride particles, and wherein the catalytic alloy is in contact with the particles at an open end of the supporting mass.

Claim 31

The improved process of claim 28 wherein the supporting mass is an annulus of cemented metal carbide or carbide molding powders wherein at least part of the cementing agent is a catalyst.

Claim 32

A polycrystalline diamond or cubic boron nitride compact containing a catalyst and an additional metal or metal alloy within the interstices between crystal grains and in which compact there is a concentration gradient of the additional metal or metal alloy.

Claim 33

A polycrystalline diamond or cubic boron nitride compact containing a catalyst and an additional metal or metal alloy within the interstices between crystal grains and in which compact there is a concentration gradient of the additional metal or metal alloy.

Claim 34

A polycrystalline compact as in claim 30 which has a first end and a second end and in which the concentration of additional metal and metal alloy is greater at one end than at the second end.