10results about How to "Increase nucleation rate" patented technology

The invention discloses a forming method of a flash memory unit. The forming method comprises the following steps: providing a semiconductor substrate; forming a tunneling oxide layer on the semiconductor substrate; forming nanocrystalline silicon particles on the tunneling oxide layer; forming an isolation insulating layer on the tunneling oxide layer and the nanocrystalline silicon particles; and forming a control grid on the isolation insulating layer, wherein the step of forming the nanocrystalline silicon particles on the tunneling oxide layer comprises: forming an amorphous silicon layer on the tunneling oxide layer; and performing repeated seed crystal particle forming processes on the amorphous silicon layer, wherein surface annealing treatment is performed between two adjacent seed crystal particle forming processes, and an annealing process is performed after the last seed crystal particle forming process. The flash memory unit can be used for storing a large quantity of electrons, and has high performance.

The application provides a method for optimizing microstructure of a neodymium-iron-boron magnet rapid solidification sheet by using ultrasonic waves, and belongs to the technical field of neodymium-iron-boron alloy rapid solidification casting sheet. The application applies ultrasonic vibration on a copper roller by using an ultrasonic wave introduction device while the copper roller is rotating, then neodymium-iron-boron alloy melt is cast onto the surface of the copper roller to obtain a neodymium-iron-boron magnet rapid solidification sheet; the initial driving frequency of the copper roller is accurately designed and the amplitude is limited during the casting process, so that the nucleation rate of the magnetic phase grains near the roller surface of the rapid solidification sheet is increased, the growth of the magnetic phase grains in the direction from the near roller surface to the far roller surface is promoted, the magnetic phase columnar crystals are effectively refined, and the uniformity of the microstructure and the thickness consistency of the rapid solidification sheet are significantly improved, so that the effects of improving the nucleation rate and inhibiting the growth of coarse crystals are achieved, and finally the rapid solidification sheet with refined columnar crystals and good orientation is obtained.

This invention discloses a method for refining primary silicon in Al-Si alloys through synergistic modification with nano-ceramics based on laser additive manufacturing. The method involves uniformly mixing Al-Si alloy powder with TiB2 and Al2O3 nano-ceramics using a ball mill under inert gas protection to obtain a ceramic-reinforced nano-Al-Si alloy composite powder. This nano-ceramic-modified Al-Si alloy powder is then melted and solidified layer by layer using a laser powder bed melting and forming equipment to create the desired target part. In this method, during the solidification of the nano-ceramic-reinforced Al-Si alloy melt, Al2O3 nanoparticles, due to their similarity to the Si crystal structure and the existence of a good interfacial coherence relationship, act as heterogeneous nucleation sites for primary silicon, increasing the nucleation rate and refining the size of primary silicon. TiB2 nanoparticles, distributed at the solid-liquid interface, can to a certain extent prevent the diffusion and aggregation of Si atoms into Si-Si atom clusters, thereby inhibiting the growth of the primary silicon phase, promoting the regularization of the primary silicon morphology and refining its size, and effectively reducing matrix grain size, significantly improving the mechanical properties of the Al-Si alloy.

This invention discloses a high-adhesion, high-temperature resistant composite coating and its preparation method, belonging to the field of surface thin film preparation technology. The method includes: micro-machining and etching a substrate material to form a periodic pattern on the substrate material surface; sandblasting; sputtering a tetrahedral amorphous carbon transition layer film on the substrate material surface; and continuing chemical vapor deposition to deposit a diamond protective film, thereby obtaining a high-adhesion, high-temperature resistant composite coating on the substrate material surface. This method can improve the nucleation rate of diamond on the substrate material and increase the bonding force between the diamond protective film and the substrate material. The tetrahedral amorphous carbon film can be bonded to different materials, such as metals, plastics, and inorganic non-metals, without the serious stress problem during deposition. Using tetrahedral amorphous carbon as a transition layer for the substrate material can increase the stability of diamond on the substrate material and effectively protect the substrate material's anti-oxidation and anti-corrosion properties at high temperatures.

The application discloses a coating material for promoting grain refinement of internal organization of a coating and a preparation method thereof. The method comprises the following steps: drying micron-sized powder, performing ultrasonic dispersion treatment, performing grinding and crushing treatment, mixing the crushed powder with a dispersant I, a binder, a defoaming agent and water to obtain a slurry; performing centrifugal spray drying on the slurry to obtain micron-sized agglomerated particles; uniformly mixing nanometer-sized powder, a solvent and a dispersant II by ultrasonic mixing to obtain a nanometer suspension; adding the micron-sized agglomerated particles into the heated nanometer suspension, uniformly mixing by magnetic stirring, performing solid-liquid separation, cooling the solid, and performing vacuum drying to obtain nanometer-micron composite particles in which the micron-sized agglomerated particles contain nanometer-sized powder; and depositing the nanometer-micron composite particles on a substrate by laser cladding to form the coating material for promoting grain refinement of internal organization of the coating. The method realizes grain refinement of internal organization of the coating and effectively improves the hardness and wear resistance of the coating.

The application provides an electroplating solution and an electroplating method for preparing nanotwinned copper, wherein the electroplating solution comprises copper sulfate, sulfuric acid, chloride ions, a polyether-type inhibitor, a sulfur-containing accelerator, a main twinning inducer and a stress biasing component, the stress biasing component comprises metal ions or metal complexes, the metal ions are not copper ions, and the metal complexes are not copper complexes. The electroplating solution of the application can regulate the dynamic adsorption layer on the cathode surface, the copper nucleation density, the local internal stress and the (111) plane preferred growth by adding the main twinning inducer and the stress biasing component and the like, so that the nanotwinned copper with a high volume fraction can be prepared under the direct current electroplating condition.

This invention relates to the field of magnesium alloy smelting technology, and in particular to a smelting process and apparatus for a semi-solid non-dendritic slurry of rare earth AS-based magnesium alloy. Using AS magnesium alloy as the base material and a Ce-La-Nd ternary rare earth mixture as the rare earth modifier, the process involves vacuum melting, electromagnetic stirring, and stepped cooling to obtain an ingot. A three-dimensional curve is plotted based on the JMAK equation to determine the critical temperature. Using a rheological casting apparatus, through internal cooling gradient, stirring-assisted slurry preparation, and ultrasonic-assisted isothermal treatment, combined with three-level quality judgment and defect closed-loop adjustment, a slurry with controllable liquid phase content, fine and rounded grains, and uniform rare earth distribution is prepared. The process exhibits high repeatability and meets the requirements of high-end semi-solid forming.

The application relates to the technical field of alloy materials, in particular to a 4341E high-speed steel and a preparation method thereof. The high-speed steel is characterized in that Ti, B and N elements are introduced for ternary micro-alloying and synergistic modification on the basis of a W-Mo-V-Co component system, nanoscale particles generated in-situ by Ti-N are used as heterogeneous cores to significantly refine grains, the grain boundary is strengthened by the grain boundary segregation effect of boron elements, and the reticular carbide is effectively broken. The obtained steel material realizes perfect matching of high hardness, excellent red hardness and excellent impact toughness, solves the problem that the strength and toughness of traditional high-speed steel are difficult to be compatible, and is particularly suitable for manufacturing high-performance cutting tools, cold and hot precision dies and high-temperature wear-resistant parts.

The invention relates to the field of metal materials, in particular to a niobium-containing 304 austenitic stainless steel plate for nuclear power and a preparation method of the niobium-containing 304 austenitic stainless steel plate for nuclear power, and the niobium-containing 304 austenitic stainless steel plate comprises the following components in percentage by mass: 0.02%-0.06% of C, 1.00%-2.00% of Mn, 0.20%-0.75% of Si, 0-0.030% of P, 0-0.005% of S, 18.00%-19.50% of Cr, 8.00%-10.50% of Ni, 0.2%-0.8% of Nb, 0-0.10% of Cu, 0-0.10% of Co, 0-0.10% of N and the balance of Fe and other inevitable impurities. The 304 austenitic stainless steel is improved, and the niobium element is added, so that stable production of the 304 austenitic stainless steel plate for nuclear power can be ensured, the 304 austenitic stainless steel plate has excellent grain size, intergranular corrosion resistance and mechanical property, and the design requirements of steel for nuclear power are met.