Abstract:
Produit obtenu par frittage en phase solide d'une poudre de carbure de silicium et d'un additif de frittage, ledit produit présentant une masse volumique relative supérieure à 98,5% et comprenant: plus de 92% poids de SiC présent sous forme de grains, moins de 2% poids d'oxygène élémentaire, moins de 6%poids,au total, d'autres éléments, ledit produit étant caractérisé en ce que : plus de 10% en nombre des grains de SiC, sur la base du nombre total desdits grains, présentent un facteur d'allongement F supérieur à 3 (F > 3), plus de 50% en nombre desdits grains, dont le facteur d'allongement F est supérieur à 3, présentent une largeur supérieure à 3micromètres, les autres grains de SiC dans ledit produit présentent un diamètre équivalent moyen supérieur à 1 micromètre et inférieur à 20 micromètres.
Abstract:
The present invention relates to a method of making a cBN material comprising the steps of: -providing a powder mixture comprising cBN grains, aluminum and a Ti(C x N y O z ) a powder, -subjecting the powder mixture to a milling to form a powder blend, -subjecting the powder blend to a forming operation to form a green body, - subjecting said green body to a pre-sintering step, at a temperature between 650 to 950°C, to form a pre-sintered body, - subjecting said pre-sintered body to a HPHT operation to form the cBN material; where the Ti(C x N y O z ) a powder is stoichiometric so that 0.05 2 O 3 phase, a binder phase of TiC, TiN and/or TiCN, W and Co, whereby a quotient Q is
Abstract translation:本发明涉及一种制备cBN材料的方法,包括以下步骤: - 提供包含cBN晶粒,铝和Ti(C x N y O z)粉末的粉末混合物, - 将粉末混合物喷射至研磨以形成粉末混合物, - 将所述粉末混合物喷射到成型操作以形成生坯, - 在650至950℃之间的温度下对所述生坯进行预烧结步骤以形成预烧结体, - 对所述预烧结体进行处理, 烧结体进行HPHT操作以形成cBN材料; 其中Ti(C x N y O z)a粉末是化学计量的,使得0.05
Abstract:
A method of making a near-net superhard material body includes preparing granules from a mixture of superhard powder, binders, and fluids, compacting the granules to form a soft green complex-shaped body, heating the soft green body in a furnace to form a hard green body free from residual binders, embedding one or more of the hard green bodies in a containment powder or a containment means and forming a pressure cell, sintering the cell at high pressure and high temperature, and removing the containment powder from the cell or removing the inserts from the containment means to reveal one or more near-net bodies.
Abstract:
Doped and partially-reduced oxide (e.g., SrTiO 3 -based) thermoelectric materials is provided. The thermoelectric materials can be single-doped or multi-doped (e.g., co-doped) and display a thermoelectric figure of merit (ZT) of 0.2 or higher at 1050K. Also provided are methods of forming the thermoelectric materials involve combining and reacting suitable raw materials and heating them in a graphite environment to at least partially reduce the resulting oxide. Optionally, a reducing agent such as titanium carbide can be incorporated into the starting materials prior to the reducing step in graphite. The reaction product can be sintered to form a dense thermoelectric material.
Abstract:
A method for forming a stand-alone wafer or a coating on a substrate uses a composite of cubic boron nitride (cBN) particles and other materials, such as nitrides, carbides, carbonitrides, borides, oxides, and metallic phase materials. The wafer or coating may be formed of a thickness up to about 1000 microns for improved wear life. The density of material within the wafer or coating may be varied according to desired parameters, and a gradient of particle sizes for the cBN may be presented across the thickness of the material.
Abstract:
A cutting tool formed by a coating layer on a substrate has cutting edges that feature serrations. The linear dimensions of the serrations may vary from a few nanometers up to 10 microns. The serrations result in a smoother cut edge on the workpiece, particularly when the workpiece is formed of certain materials that are seen as particularly difficult to cut, such as hardened steels.