A diamond polycrystal includes diamond grains, the diamond polycrystal including a cubic diamond and a 6H type hexagonal diamond, wherein the cubic diamond and the 6H type hexagonal diamond exist in the same or different diamond grains, and a ratio Ab.sub.1/Ab.sub.2 is more than or equal to 0.4 and less than or equal to 1, Ab.sub.1 representing a maximum value of absorption in a range of more than or equal to 1200 cm.sup.−1 and less than or equal to 1300 cm.sup.−1 in an infrared absorption spectrum, Ab.sub.2 representing a maximum value of absorption in a range of more than or equal to 1900 cm.sup.−1 and less than or equal to 2100 cm.sup.−1.

A polycrystalline diamond structure comprises a first region and a second region adjacent the first region, the second region being bonded to the first region by intergrowth of diamond grains. The first region comprises a plurality of alternating strata or layers, each or one or more strata or layers in the first region having a thickness in the range of around 5 to 300 microns. The polycrystalline diamond (PCD) structure has a diamond content of at most about 95 percent of the volume of the PCD material, a binder content of at least about 5 percent of the volume of the PCD material, and one or more of the layers or strata in the first region comprise and/or the second region comprises diamond grains having a mean diamond grain contiguity of greater than about 60 percent and a standard deviation of less than about 2.2 percent. There is also disclosed a method of making such a polycrystalline diamond structure.

A diamond polycrystal includes diamond grains, the diamond polycrystal including a cubic diamond and a 6H type hexagonal diamond, wherein the cubic diamond and the 6H type hexagonal diamond exist in the same or different diamond grains, and a ratio Ab.sub.1/Ab.sub.2 is more than or equal to 0.4 and less than or equal to 1, Ab.sub.1 representing a maximum value of absorption in a range of more than or equal to 1200 cm.sup.1 and less than or equal to 1300 cm.sup.1 in an infrared absorption spectrum, Ab.sub.2 representing a maximum value of absorption in a range of more than or equal to 1900 cm.sup.1 and less than or equal to 2100 cm.sup.1.

Provided is polycrystalline diamond having a diamond single phase as basic composition, in which the polycrystalline diamond includes a plurality of crystal grains and contains boron, hydrogen, oxygen, and the remainder including carbon and trace impurities; the boron is dispersed in the crystal grains at an atomic level, and greater than or equal to 90 atomic % of the boron is present in an isolated substitutional type; hydrogen and oxygen are present in an isolated substitutional type or an interstitial type in the crystal grains; each of the crystal grains has a grain size of less than or equal to 500 nm; and the polycrystalline diamond has a surface covered with a protective film.

Nano polycrystalline diamond is composed of carbon, an element of different type which is an element other than carbon and is added to be dispersed in carbon at an atomic level, and an inevitable impurity. The polycrystalline diamond has a crystal grain size not greater than 500 nm. The polycrystalline diamond can be fabricated by subjecting graphite in which the element of different type which is an element other than carbon has been added to be dispersed in carbon at an atomic level to heat treatment within high-pressure press equipment.

The present invention relates to a high pressure homogenizer and a method for manufacturing graphene using the same, and according to one aspect of the present invention, there is provided a high pressure homogenizer comprising a channel module which comprises a microchannel through which an object for homogenization passes, wherein the channel module comprises at least one baffle disposed so as to partition the microchannel into a plurality of spaces and the baffle is provided so as to partition the microchannel into two spaces along the width direction or the height direction.

A polycrystalline diamond construction comprising a body of polycrystalline diamond material formed of a mass of diamond grains exhibiting inter-granular bonding, wherein between around 50 wt % to around 99 wt % of the diamond grains in a cross-section of the body of polycrystalline diamond material taken at any orientation have a sectorial growth structure. A method of making the polycrystalline diamond construction is also disclosed.

The present invention relates to a high pressure homogenizer and a method for manufacturing graphene using the same, and according to one aspect of the present invention, there is provided a high pressure homogenizer comprising a channel module which comprises a microchannel through which an object for homogenization passes, wherein the channel module comprises at least one baffle disposed so as to partition the microchannel into a plurality of spaces and the baffle is provided so as to partition the microchannel into two spaces along the width direction or the height direction.

A polycrystalline diamond construction comprising a body of polycrystalline diamond material formed of a mass of diamond grains exhibiting inter-granular bonding, wherein between around 50 wt % to around 99 wt % of the diamond grains in a cross-section of the body of polycrystalline diamond material taken at any orientation have a sectorial growth structure. A method of making the polycrystalline diamond construction is also disclosed.

A method of forming polycrystalline diamond comprised placing a plurality of graphene nano-platelets into a capsule; and subjecting the platelets to a pressure of around 10 GPa to around 20 GPa and a temperature of around 1600 degrees Celsius to around 3000 degrees Celcius to convert the graphene platelets to nano-polycrystalline diamond. There is also disclosed a polycrystalline super hard construction comprising a polycrystalline diamond region comprising polycrystalline diamond material formed according to said method.