9results about How to "High Vickers hardness" patented technology

The invention discloses a method for manufacturing a CoCrNi medium-entropy alloy by TiC ceramic powder-enhanced laser additive manufacturing. The method comprises the following steps: S1, selecting CoCrNi alloy powder and TiC ceramic powder with a particle size of (10-60) μm; S2, mixing the CoCrNi and TiC powders by mechanical ball milling, wherein the atomic ratio of the two powders is CoCrNi:TiC=(0.8-1):(0.1-0.2); S3, vacuum drying the mixed powder, and preparing a TiC ceramic powder-enhanced CoCrNi medium-entropy alloy material with fewer defects and excellent performance by using a laser selective melting (SLM) technique; the invention reduces the generation of cracks and pores in the process of additive manufacturing, and reduces the generation of defects inside the printed material; improves the density and Vickers hardness of the CoCrNi medium-entropy alloy, refines the average grain size, etc., and prepares a CoCrNi / TiC medium-entropy alloy with better performance; the invention adds a specific proportion of TiC ceramic powder, which can effectively achieve the effect of refining grains and reducing internal defects.

A gradient multilayer nano Ti (C, N)-based metal ceramic and a preparation method thereof relate to the field of powder metallurgy, and the method comprises the following steps: S1, mixing 64.9% by mass of titanium carbonitride, 23% by mass of tungsten carbide, 8% by mass of cobalt, 4% by mass of molybdenum carbide and 0.1% by mass of graphene nanosheets to obtain mixed powder I; mixing 60.9% of titanium carbonitride, 23% of tungsten carbide, 8% of cobalt, 8% of molybdenum carbide and 0.1% of graphene nanosheets to obtain mixed powder II; and S2, the mixed powder I and the mixed powder II are added into a mold layer by layer, three layers of mixed powder with the surface layer being the mixed powder II layer and the core layer being the mixed powder I layer are obtained, spark plasma sintering is carried out, and the gradient multi-layer nano Ti (C, N)-based metal ceramic is obtained. According to the Ti (C, N)-based metal ceramic and the preparation method thereof, different molybdenum carbide mass proportions of the surface layer and the core layer are controlled, a hard phase enrichment area is formed on the surface layer, a binding phase enrichment area is formed on the inner core part, the Vickers hardness can be improved through hard phase enrichment, the fracture toughness can be improved through binding phase enrichment, and therefore the Ti (C, N)-based metal ceramic with the hardness and the fracture toughness is obtained.

The invention discloses iron yellow glaze fired by reducing flame and a preparation method of the iron yellow glaze, and belongs to the technical field of domestic ceramics. The iron yellow glaze fired by reducing flame comprises the following raw materials in parts by weight: 38-42 parts of feldspar, 8-12 parts of quartz, 8-12 parts of talc, 8-12 parts of dolomite, 12-15 parts of bone carbon, 10-15 parts of iron oxide red, 8-12 parts of Jiepai mud, 3-8 parts of Longyan soil and 4-8 parts of titanium dioxide. The preparation method comprises the following steps: weighing raw materials, adding water, stirring, carrying out ball milling, glazing, firing and the like. The prepared yellow glaze is good in water resistance, high in Vickers hardness, good in wear resistance, good in thermal shock resistance, glossy in glaze surface and fine and smooth in hand feeling.

This invention discloses a method for removing metallic impurities from recycled tungsten alloys through arc refining and synergistic additive processes, belonging to the field of recycled tungsten alloy purification technology. The method includes: a first step, pretreatment; a second step, arc refining and synergistic additive impurity removal; a third step, cooling and forming; and a fourth step, post-treatment. This invention achieves highly efficient and thorough impurity removal, effectively removing various metallic impurities such as Fe, Cu, Al, Si, Mo, As, Pb, and Bi from recycled tungsten alloys. The finished product has a low total metallic impurity content and high purity, meeting the purity requirements of high-end applications for high-purity tungsten alloys.

The invention relates to the technical field of liquid metal materials, in particular to a liquid metal material and a preparation method thereof.The liquid metal material comprises, by mass, 10-18 parts of Cd, 10-20 parts of Pb, 25-30 parts of Bi, 4-17 parts of In, 5-15 parts of Al, 20-35 parts of Zn, 10-20 parts of Sn and 8-20 parts of Nb. The total mass fraction of Pb and Cd is greater than the mass fraction of Bi. The mass part ratio of Sn to Zn to Al is (10-14): (23-27): (6-10). The liquid metal material is solid at the temperature of 20-50 DEG C, can be melted at the temperature of 100 DEG C or above, can be melted at the high temperature and can be solidified at the low temperature, is used for underground plugging and casing annulus plugging, and is excellent in comprehensive performance.

The invention belongs to the technical field of electric contact materials, and relates to a nickel-containing AgZnO electric contact material and a preparation method thereof. The preparation method of the nickel-containing AgZnO electric contact material comprises the following steps: (1) preparing nickel-containing ZnO composite powder by adopting a sol-gel method; (2) adding Ag powder and the nickel-containing ZnO composite powder into a container, adding a solvent, carrying out ultrasonic mixing, and drying to obtain a mixture; (3) pressing the mixed material obtained in the step (2) into a blank, sintering for the first time in an inert atmosphere, and cooling to room temperature after sintering to obtain a prefabricated material; and (4) carrying out compression molding on the prefabricated material obtained in the step (3) again, carrying out secondary sintering in an inert atmosphere, and cooling to room temperature after sintering to obtain the nickel-containing AgZnO electric contact material. Compared with an AgZnO electric contact material prepared from ZnO, the density, the conductivity and the Vickers hardness of the obtained nickel-containing AgZnO electric contact material are increased by 2.8%, 13.5% and 28.8% respectively.

The present invention discloses a high mechanical property conductive WC / β-SiAlON composite ceramic tool material and a preparation method thereof, and belongs to the technical field of ceramic material preparation. The high mechanical property conductive WC / β-SiAlON composite ceramic tool material of the present invention, in terms of volume percentage, comprises raw materials including: 70-80% β-SiAlON ceramic powder and 20-30% WC powder. The WC / β-SiAlON composite ceramic tool material of the present invention has good electrical conductivity and high mechanical properties, with its resistivity being reduced to 0.64Ω·m, its Vickers hardness being up to 17.23±0.29GPa, and its fracture toughness being up to 7.09±0.14MPa·m 1 / 2 Compared with pure β-SiAlON ceramics without the addition of a second phase, the resistivity decreases by about 10 10 times, the Vickers hardness increased by 4.68%, and the fracture toughness increased by 4.11%.

The invention belongs to the technical field of carbon materials, and provides an sp2 hybridized nano composite carbon material with high hardness and superelasticity and a preparation method thereof, the carbon material is obtained by molding an sp2 hybridized carbon raw material under the action of temperature and pressure, in the forming process, the sp2 hybrid carbon raw material reacts to form a blocky structure mainly composed of amorphous carbon and crystal graphite clusters; the size distribution of the crystal graphite cluster is below 10nm; the mass ratio of sp2 hybrid carbon atoms in the blocky structure is more than 90%; the Vickers hardness value of the blocky structure is 20 GPa or above, the indentation elastic recovery rate is 90% or above, the initial oxidation temperature is about 900 DEG C or above, the room-temperature conductivity is 1 * 10 < 5 > S / m or above, and the blocky structure has wide application prospects in the fields of micro-nano electronic devices, aerospace and the like. The method disclosed by the invention is rich in raw material source, simple to operate and easy in condition control, and has the potential of industrial large-scale production.

The present invention belongs to the technical field of silicon nitride ceramics, and specifically relates to a silicon nitride ceramic tool and a preparation method thereof. The preparation method comprises the following steps: firstly weighing the following components by weight percentage: 75%-85% silicon nitride powder, 10%-16% pre-oxidized silicon nitride powder and ZrO 2 ‑Y 2 O 3 5%-10% of the powder is stirred with water and ethanol to prepare a ceramic slurry; the ceramic slurry is sprayed in a hot air flow, granulated, dried, ground, and sieved to obtain a ceramic powder; the ceramic powder is pressed into a shape to obtain a ceramic body; the ceramic body is sintered to obtain a silicon nitride ceramic tool. The silicon nitride ceramic tool obtained by the present invention has a Vickers hardness of 21.6-27.5GPa and a fracture toughness of 12.7-15.8MPa·m 1 / 2 , the flexural strength is 1053‑1290MPa.