Composite polycrystal and method for manufacturing the same

A composite polycrystal comprising:

• a polycrystalline diamond phase including a plurality of diamond particles;
• and
• non-diamond phases composed of non-diamond carbon,
• the non-diamond phases being distributed in the polycrystalline diamond phase,
• an average value of projected area equivalent circle diameters of the non-diamond phases being not more than 1000 nm,
• an average value of projected area equivalent circle diameters of the diamond particles being not more than 100 nm,
• a Knoop hardness of the composite polycrystal being not less than 50 GPa,
• wherein the composite polycrystal is a sintered material.

A composite polycrystal comprising:

• a polycrystalline diamond phase including a plurality of diamond particles;
• and
• non-diamond phases composed of non-diamond carbon,
• the non-diamond phases being distributed in the polycrystalline diamond phase,
• an average value of projected area equivalent circle diameters of the non-diamond phases being not more than 1000 nm,
• wherein the composite polycrystal is a sintered material, and
• wherein the composite polycrystal is manufactured under a condition satisfying all of following equations (I) to (IV):
• P≤0.0067T+1 (I);
• P≥0.0035T−0.3462 (II);
• 0≤T≤2700 (III);
• and
• 0≤P≤13 (IV)
• where P [GPa] represents a sintering pressure and T [° C.] represents a sintering temperature,
• the sintering pressure being not less than 9 GPa and not more than 13 GPa, and
• the sintering temperature being not lower than 1800° C. and not higher than 2700° C.