There is provided a composite of a metallic matrix and boron nitride nanotubes, the metallic matrix including aluminum or an aluminum alloy. Also, there is provided a method for manufacturing the composite. The method includes: a powder mixing step of mixing a powder of boron nitride nanotubes and a powder of an element soluble in a molten metal of the metallic matrix to prepare a powder mixture of boron nitride nanotubes and a metallic matrix-soluble element; an alloy melt mixing step of mixing the powder mixture and the molten metal of the metallic matrix to prepare a metallic matrix melt mixed with boron nitride nanotubes; and a casting step of solidifying the metallic matrix melt mixed with boron nitride nanotubes to obtain the composite.

The present application is a new improvement in the fine-grained cubic Boron Nitride sintered compact which may be employed to manufacture a cutting tool. The compact contains at least 80 vol % cBN and is sintered under HPHT conditions. The invention has lower levels of unreacted cobalt in the final sintered material than conventions materials. The invention has proved beneficial in the machining of ferrous metal alloys such as sintered metal alloys.

A composite sintered material includes: a plurality of diamond grains having an average grain size of less than or equal to 10 m; a plurality of cubic boron nitride grains having an average grain size of less than or equal to 2 m; and a remainder of a binder phase, wherein at least parts of adjacent diamond grains are bound to one another, the binder phase includes cobalt, in the composite sintered material, a content of the diamond grains is more than or equal to 30 volume % and less than or equal to 94 volume %, a content of the cubic boron nitride grains is more than or equal to 3 volume % and less than or equal to 40 volume %, and a content of the cobalt is more than or equal to 3 volume % and less than or equal to 30 volume %.

The present application is a new improvement in the fine-grained cubic boron nitride sintered compact which may be employed to manufacture a cutting tool. The compact contains at least 80 vol % cBN with a metallic binder system and is sintered under HPHT conditions. The improvement incorporates alloys of aluminum in the metallic binder system.

A cutting tool includes a base material, and a coating film covering the base material in contact with the base material. The base material is a cubic boron nitride sintered material. The coating film is a ceramic. An amount of oxygen in the coating film is less than or equal to 0.040 mass percent.

Conventional sintering processes convert a portion of cBN to hBN which is softer than cBN which negatively affects functional properties of an alumina composite. The invention is directed to method for making an alumina-cubic boron nitride (Al.sub.2O.sub.3-cBN) composite that contains substantially no hexagonal boron nitride (hBN) by non-conventional spark plasma sintering of cBN with nano-sized alumina particles. The invention is also directed to Al.sub.2O.sub.3-cBN/Ni composites, which contain substantially no hBN, and which exhibit superior physical and mechanical properties compared to alumina composites containing higher amounts of hBN.

The present invention relates to tungsten-rhenium coated compounds, materials formed from tungsten-rhenium coated compounds, and to methods of forming the same. In embodiments, tungsten and rhenium are coated on ultra hard material particles to form coated ultra hard material particles, and the coated ultra hard material particles are sintered at high temperature and high pressure.

A thixotropically molded product includes: a matrix portion containing Mg as a main component; and a first particle portion dispersed in the matrix portion and containing c-BN or w-BN as a main component. An average particle diameter of the first particle portion in a cross section is 10.0 ?m or less, and an area fraction of the first particle portion in the cross section is 2.0% or more and 20.0% or less.

A method of forming a super hard polycrystalline construction comprises forming a liquid suspension of a first mass of nano-ceramic particles and a mass of particles or grains of super hard material having an average particle or grain size of 1 or more microns, dispersing the particles or grains in the liquid suspension to form a substantially homogeneous suspension, drying the suspension to form an admix of the nano-ceramic and super hard grains or particles, and forming a pre-sinter assembly comprising the admix. The pre-sinter assembly is then sintered to form a body of polycrystalline super hard material comprising a first fraction of super hard grains and a second fraction, the nano-ceramic particles forming the second fraction. The super hard grains are spaced along at least a portion of the peripheral surface by one or more nano-ceramic grains, the super hard grains having a greater average grain size than that of the grains in the second fraction which have an average size of less than around 999 nm.

Polycrystalline cubic boron nitride, PCBN, material and methods of making PCBN. A method includes providing a matrix precursor powder comprising particles having an average particle size no greater than 250 nm, providing a cubic boron nitride, cBN, powder comprising particles of cBN having an average particle size of at least 0.2 intimately mixing the matrix precursor powder and the cBN powder,and sintering the intimately mixed powders at a temperature of at least 1100 C. and a pressure of at least 3.5 GPa to form the PCBN material comprising particles of cubic boron nitride, cBN dispersed in a matrix material.