A cubic boron nitride sintered body including cubic boron nitride and a binder phase, wherein a content of the cubic boron nitride is 40 volume % or more and 70 volume % or less; a content of the binder phase is 30 volume % or more and 60 volume % or less; an average particle size of the cubic boron nitride is 0.1 μm or more and 3.0 μm or less; the binder phase contains TiN and/or TiCN, and TiB.sub.2 and contains substantially no AIN and/or Al.sub.2O.sub.3, the binder phase has a TiB.sub.2 (101) plane that shows a maximum peak position (2θ) in X-ray diffraction of 44.2° or more; and I.sub.2/I.sub.1 is 0.10 or more and 0.55 or less, where denotes an X-ray diffraction intensity of a (111) plane of the cubic boron nitride and I.sub.2 denotes an X-ray diffraction intensity of a (101) plane of TiB.sub.2 of the binder phase.

A ceramic composite and a method of preparing the same are provided. The method of preparing the ceramic composite includes mixing an aluminum slag and a carbon accelerator to obtain a mixture and reacting the mixture at a temperature equal to or greater than 1600° C. in a nitrogen atmosphere to obtain a ceramic composite. The aluminum slag includes aluminum, oxygen, nitrogen, and magnesium. The weight ratio of the oxygen to the aluminum is 0.6 to 2. The weight ratio of the nitrogen to the aluminum is 0.1 to 1.2. The weight ratio of the magnesium to the aluminum is 0.04 to 0.2. The ceramic composite includes aluminum nitride accounting for at least 90 wt % of the ceramic composite.

A cubic boron nitride sintered material includes: more than or equal to 20 volume % and less than 80 volume % of cubic boron nitride grains; and more than 20 volume % and less than or equal to 80 volume % of a binder phase, and when a carbon content is measured from a cubic boron nitride grain into the binder phase in a direction perpendicular to an interface between the cubic boron nitride grain and the binder phase using TEM-EDX, a first region having a carbon content larger than an average value of a carbon content of the binder phase exists, the interface exists in the first region, and a length of the first region is more than or equal to 0.1 nm and less than or equal to 10 nm.

A surface-coated cutting tool according to the present invention includes a tool body and a hard coating layer including a complex carbonitride layer containing a small amount of chlorine and (Ti.sub.(1-x)Zr.sub.xyHf.sub.x(1-y))(N.sub.(1-z)C.sub.z) (0.10≤x≤0.90, 0<y≤1.0, 0.08<z<0.60), a ZrHf and C content ratios in cycles, a cycle distance between a maximum ZrHf content point and an adjacent minimum ZrHf content point and a cycle distance between a maximum C content point and an adjacent minimum C content point are 5 to 100 nm, an average value of content ratio differences Δx and Δz is 0.02 or more, a distance between the maximum ZrHf content point and the maximum C content point is ⅕ or less of the distance between a maximum content point and a minimum content point of adjacent ZrHf components, and a composition fluctuation structure is 10% or more.

Provided is a boron nitride sintered body including boron nitride particles and pores, in which an average pore diameter of the pores is less than 2 μm. Provided is a method for manufacturing a boron nitride sintered body, the method including: a nitriding step of firing a boron carbide powder in a nitrogen pressurized atmosphere to obtain a fired product containing boron carbonitride; and a sintering step of molding and heating a blend containing the fired product and a sintering aid to obtain the boron nitride sintered body including boron nitride particles and pores, in which the sintering aid contains boron oxide and calcium carbonate, and the blend contains 1 to 20 parts by mass of a boron compound and a calcium compound in total with respect to 100 parts by mass of the fired product.

A cBN sinter comprising cubic boron nitride grains and a binder phase, the binder phase comprising Ti.sub.2CN and Co.sub.2B, wherein the ratio I.sub.Ti2CN/I.sub.Co2B of a peak intensity I.sub.Ti2CN assigned to Ti.sub.2CN appearing at 2θ = 41.9° to 42.2° to a peak intensity I.sub.TiAl3 assigned to Co.sub.2B appearing at 2θ = 45.7° to 45.9° is in a range of 0.5 and 2.0 in an XRD measurement.

Provided is a method for manufacturing a composite body, the method including: a nitriding step of firing a boron carbide powder in a nitrogen atmosphere to obtain a fired product containing boron carbonitride; a sintering step of molding and heating a blend containing the fired product and a sintering aid to obtain a boron nitride sintered body including boron nitride particles and pores; and an impregnating step of impregnating the boron nitride sintered body with a resin composition, the composite body having the boron nitride sintered body and a resin filled in at least some of the pores of the boron nitride sintered body.

Provided is a boron nitride sintered body including: a plurality of coarse particles each having a length of 20 μm or more; and fine particles smaller than the plurality of coarse particles, in which, when viewed in a cross-section, the plurality of coarse particles intersect with each other. Provided is a method for manufacturing a boron nitride sintered body, the method including: a raw material preparation step of firing a mixture containing boron carbonitride and a boron compound in a nitrogen atmosphere to obtain lump boron nitride having an average particle diameter of 10 to 200 μm; and a sintering step of molding and heating a blend containing the lump boron nitride and a sintering aid to obtain a boron nitride sintered body including coarse particles each having a length of 20 μm or more in a cross-section and fine particles smaller than the coarse particles.

Provided is a boron nitride sintered body having a porous structure, the boron nitride sintered body including a lump particle formed by aggregation of primary particles of boron nitride and having a particle diameter of 15 μm or more. Provided is a method for manufacturing a boron nitride sintered body, the method including: a nitriding step of firing a raw material powder containing boron carbide in an atmosphere containing nitrogen to obtain a fired product including lump particles each having a core part with primary particles of boron carbonitride aggregated and a shell part surrounding the core part; and a firing step of molding and heating a blend containing the fired product including lump particles and a sintering aid to obtain the boron nitride sintered body having a porous structure and including lump particles of boron nitride.

A super hard polycrystalline construction is disclosed as comprising a first region comprising a body of thermally stable polycrystalline diamond material comprising a plurality of intergrown grains of diamond material; a second region forming a substrate to the first region; and a third region interposed between the first and second regions. The third region extends across a surface of the second region along an interface. The interface comprises at least a portion having an uneven topology, and the third region comprises a diamond composite material including a first phase comprising a plurality of non-intergrown super hard grains, said super hard grains comprising diamond grains; and a matrix material. The superhard material and matrix material of the third region form a diamond composite material which is more acid resistant than polycrystalline diamond material having a binder-catalyst phase comprising cobalt, and/or more acid resistant than cemented tungsten carbide material.