A polycrystalline cubic boron nitride comprising 98.5% by volume or more of cubic boron nitride, wherein the cubic boron nitride has a dislocation density of more than 8×10.sup.15/m.sup.2, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of 0.1 μm or more and 0.5 μm or less.

Systems and methods include a computer-implemented method can be used to make drilling tools from new wurtzite boron nitride (w-BN) superhard material. An ultra-high-pressure, high-temperature operation is performed on pure w-BN powder to synthesize w-BN and cubic boron nitride (c-BN) compact having a first size greater than particles of the pure w-BN powder. The ultra-high-pressure, high-temperature operation includes pressurizing the w-BN powder to a pressure of approximately 20 Gigapascal, heating the w-BN powder at a heating rate of 100° C./minute and cooling the w-BN powder at a cooling rate of 50° C./minute. The compact is cut to a second size smaller than the first size using laser cutting tools. The cut compact is bonded metallurgically, mechanically, or both metallurgically and mechanically onto a tool substrate to form the drilling tool.

The present invention relates to a method of preparing a solid solution ceramic material having increased electromechanical strain, as well as ceramic materials obtainable therefrom and uses thereof. In one aspect, the present invention provides a method A method of increasing electromechanical strain in a solid solution ceramic material which exhibits an electric field induced strain derived from a reversible transition from a non-polar state to a polar state; i) determining a molar ratio of at least one polar perovskite compound having a polar crystallographic point group to at least one non-polar perovskite compound having a non-polar crystallographic point group which, when combined to form a solid solution, forms a ceramic material with a major portion of a non-polar state; ii) determining the maximum polarization, P.sub.max, remanent polarisation, P.sub.r, and the difference, P.sub.max−P.sub.r, for the solid solution formed in step i); and either: iii)a) modifying the molar ratio determined in step i) to form a different solid solution of the same perovskite compounds which exhibits an electric field induced strain and which has a greater difference, P.sub.max−P.sub.r, between maximum polarization, P.sub.max, and remanent polarisation, P.sub.r, than for the solid solution from step i), or; iii)b) adjusting the processing conditions used for preparing the solid solution formed in step i) to increase the difference, P.sub.max−P.sub.r, in maximum polarization, P.sub.max, and remanent polarisation, P.sub.r, of the solid solution.

A cubic boron nitride sintered material includes: 20 to 80 volume % of cBN grains; and 20 to 80 volume % of a binder phase, wherein the binder phase includes first binder grains and second binder grains, in each of the first binder grains, a ratio of the number of atoms of the first metal element to a total of the number of atoms of the titanium and the number of atoms of the first metal element is more than or equal to 0.01% and less than 10%, in each of the second binder grains, this ratio is more than or equal to 10% and less than or equal to 80%, and in an X-ray diffraction spectrum of the cubic boron nitride sintered material, one or both of conditions 1 and 2 are satisfied.

The invention relates to the use of a printing sol as construction material in an additive manufacturing process for producing a 3-dim article, the printing sol comprising solvent(s), nano-sized crystalline zirconia particles in an amount from 2 to 25 vol.-% with respect to the volume of the sol, the average primary particle size of the nano-sized crystalline zirconia particles being in a range up to 50 nm, a first monomer being a polymerizable surface modification agent represented by formula A-B, with A being capable of attaching to the surface of the nano-sized crystalline zirconia particles and B being a radiation curable group, optionally a second monomer, the second monomer comprising at least one radiation curable moiety but no acidic or silane group(s), photo initiator(s). The invention also relates to a ceramic article obtainable according to such a process.

A knife includes a blade having a first side face and a second side face. The blade includes zirconia as a main component, and includes a cutting region including at least a ridge portion between the first side face and the second side face. When a portion including the cutting region in the first side face is referred to as a first cutting face, and a portion including the cutting region in the second side face is referred to as a second cutting face, the proportion of cubic crystals of zirconia in the first cutting face is larger than the proportion of cubic crystals of zirconia in the second cutting face.

A ceramic powder material which contains an LLZ-based garnet-type compound represented by Li.sub.7−3xAl.sub.xLa.sub.3Zr.sub.2O.sub.12 (where x satisfies 0≤x≤0.3) and in which a main phase of a crystal phase undergoes phase transition from a tetragonal phase to a cubic phase in the process of raising a temperature from 25° C. to 1050° C. and the main phase is the cubic phase even after the temperature is lowered to 25° C.

Sintered bead that has a crystalline composition, as percentages by weight based on the total weight of the crystalline phases: zircon<25%; 50%≤cubic zirconia+tetragonal zirconia≤95%, the cubic zirconia content being greater than 50%, the cubic zirconia content being the (cubic zirconia/(cubic zirconia+tetragonal zirconia) ratio by weight); 0≤monoclinic zirconia≤(10−0.2*tetragonal zirconia) %; 5%≤corundum≤50%; crystalline phases other than zircon, cubic zirconia, tetragonal zirconia, monoclinic zirconia and corundum<10%; and the following chemical composition, as percentages by weight based on the oxides: 34%≤ZrO.sub.2+HfO.sub.2, ZrO.sub.2+HfO.sub.2 being the remainder to 100%; HfO.sub.2≤4.0%; 0.5%≤SiO.sub.2≤14.1%; 4.5%≤Al.sub.2O.sub.3≤49.6%; 2.75%≤Y.sub.2O.sub.3≤22.8%; MgO≤5%; CaO≤2%; oxides other than ZrO.sub.2, HfO.sub.2, SiO.sub.2, Al.sub.2O.sub.3, MgO, CaO and Y.sub.2O.sub.3<5.0%.

A cBN sintered compact comprising a cubic boron nitride and a ceramic binder phase, wherein a cubic C-containing Ta compound in an amount of 1.0 to 15.0 vol % is dispersed in the ceramic binder phase and has a mean particle diameter of 50 to 500 nm.

A zirconia sintered body may excel in translucency, strength, and linear light transmittance with no use of an HIP device, and a zirconia molded body and a zirconia pre-sintered body from which such a zirconia sintered body can be obtained. A zirconia molded body may include zirconia particles with 2.0 to 9.0 mol % yttria, an average primary particle diameter of 60 nm or less, and 0.5 mass % or less zirconia particles having a particle diameter >100 nm, wherein the zirconia molded body has ΔL*(W−B) of 5+ through a thickness of 1.5 mm. A zirconia pre-sintered body may include 2.0 to 9.0 mol % yttria, and have a ΔL*(W−B) of 5+ through a thickness of 1.5 mm. A zirconia sintered body may include: a fluorescent agent; 2.0 to 9.0 mol % yttria, and have a linear light transmittance of 1% or more through a thickness of 1.0 mm.