Polycrystalline diamond material

Abstract

A polycrystalline diamond material comprising a mass of diamond particles or grains exhibiting inter-granular bonding and a binder material comprises a non-metallic catalyst material for diamond, the non-metallic catalyst material for diamond comprising at least one nitrogen compound derived from an ammonium compound and/or at least one halide compound.

1 . A polycrystalline diamond material comprising a mass of diamond particles or grains exhibiting inter-granular bonding and a binder material comprising a non-metallic catalyst material for diamond, the non-metallic catalyst material for diamond comprising at least one nitrogen compound derived from an ammonium compound and/or at least one halide compound. 
     
     
         2 . A polycrystalline diamond material according to  claim 1 , wherein the ammonium compound comprises an anion selected from the group comprising the carbonates, phosphates, hydroxides, oxides, sulphates, borates, titanates, silicates, halides, and combinations thereof. 
     
     
         3 . A polycrystalline diamond material according to  claim 1 , wherein the halide compound comprises a cation selected from the group comprising the alkali metals, alkali earth metals, transition metals, ammonium, and combinations thereof. 
     
     
         4 . A polycrystalline diamond material according to  claim 3 , wherein the non-metallic catalyst material for diamond comprises one or more of lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride, magnesium chloride, calcium chloride, strontium chloride, barium chloride, yttrium chloride, zirconium chloride, zinc chloride, niobium chloride, oxidation states thereof, and/or mixtures thereof. 
     
     
         5 . A polycrystalline diamond material according to  claim 1 , wherein the diamond particles or grains have an average particle or grain size of from about 5 nanometres to about 50 microns. 
     
     
         6 . A polycrystalline diamond material according to  claim 1 , wherein the diamond content of the polycrystalline diamond material is at least 80 percent and at most 98 percent of the volume of the polycrystalline diamond material. 
     
     
         7 . A polycrystalline diamond material according to  claim 1 , wherein the polycrystalline diamond material comprises at most 20 volume percent of the non-metallic catalyst material for diamond. 
     
     
         8 . A method for making polycrystalline diamond material, the method including providing a mass of diamond particles or grains, contacting the diamond particles or grains with a binder material comprising a non-metallic catalyst material for diamond, the non-metallic catalyst material for diamond comprising at least one ammonium compound and/or at least one halide compound, consolidating the diamond particles or grains and binder material to form a green body, and subjecting the green body to a temperature and pressure at which diamond is thermodynamically stable, sintering and forming polycrystalline diamond material. 
     
     
         9 . A method according to  claim 8 , wherein the ammonium compound comprises an anion selected from the group comprising the carbonates, phosphates, hydroxides, oxides, sulphates, borates, titanates, silicates, halides, and combinations thereof. 
     
     
         10 . A method according to  claim 8 , wherein the halide compound comprises a cation selected from the group comprising the alkali metals, alkali earth metals, transition metals, ammonium, and combinations thereof. 
     
     
         11 . A method according to  claim 10 , wherein the non-metallic catalyst material for diamond comprises any one or more of lithium chloride, sodium chloride, potassium chloride, rubidium chloride, caesium chloride, magnesium chloride, calcium chloride, strontium chloride, barium chloride, yttrium chloride, zirconium chloride, zinc chloride, niobium chloride, all oxidation states thereof, and/or mixtures thereof. 
     
     
         12 . A method according to  claim 8 , wherein the method includes subjecting the green body in the presence of the non-metallic catalyst material for diamond to a pressure and temperature at which diamond is more thermodynamically stable than graphite. 
     
     
         13 . A method according to  claim 12 , wherein the pressure is at least about 4 GPa and the temperature is at least about 1000° C. 
     
     
         14 . A method according to  claim 12 , wherein the pressure is at most about 8 GPa and the temperature is at most about 2300° C. 
     
     
         15 . A wear element comprising a polycrystalline diamond material according to  claim 1 .