49 results about "Magnesium boride" patented technology

Conducting and superconducting doped, magnesium boride materials are formed by a process which combines physical vapor deposition with chemical vapor deposition by physically generating magnesium vapor in a deposition chamber and introducing a boron containing precursor and a dopant into the chamber which combines with the magnesium vapor to form the material. Embodiments include forming carbon-doped magnesium diboride film and powder with hybrid physical-chemical vapor deposition (HPCVD) by adding a carbon-containing metalorganic magnesium precursor, bis(methylcyclopentadienyl)magnesium, with a hydrogen carrier gas together with a borane precursor in a chamber having a source of magnesium vapor.

The invention discloses a hexagonal boron nitride two-dimensional ultrathin nanometer sheet as well as a preparation method and application thereof and belongs to the technical field of nanometer materials. According to the invention, metal boride (such as calcium boride, lanthanum boride, magnesium boride, titanium boride and the like) is adopted as a boron resource; ammonium salt (such as ammonium chloride, ammonium bromide, ammonium nitrate and the like) is adopted as a nitrogen source; and the hexagonal boron nitride two-dimensional ultrathin nanometer sheet with the thickness of 0.5-4.0nm is obtained through the reaction under a mild condition (at the temperature of 500-600 DEG C). The invention aims to realize the macro-quantity preparation of the hexagonal boron nitride two-dimensional ultrathin nanometer sheet at the mild temperature by adopting cheaper raw materials; the preparation method has the advantages of saving the energy, simplifying the experimental step and greatly reducing the product cost; and due to the high heat conductivity, heat stability and chemical stability, the hexagonal boron nitride two-dimensional ultrathin nanometer sheet can be applied to the fields of heat dissipation materials, polymer filling materials, catalyst carriers and the like.

The invention discloses a solid-phase synthesis method of a Mg(BH4)2 hydrogen storage material. Magnesium boride or a mixture of magnesium boride and magnesium hydride is used as a starting material to carry out a mechanochemical reaction in high pressure hydrogen atmosphere, with a catalyst selected from one or more of a transition metal, a transition metal halide, a transition metal hydride and a transition metal oxide, so as to prepare the Mg(BH4)2. The preparation method of the Mg(BH4)2 hydrogen storage material of the invention has advantages of simple synthetic method, easily controlled reaction process, low cost and no organic pollution.

The preparation process of magnesium diboride superconductor features that magnesium diboride superconductor is prepared in strong magnetic field. Magnesium powder and boron powder in stoichiometric ratio are mixed homogeneously, the mixture is prepared into lump or belt sample, and the lump or belt sample is set heating furnace with Ar atmosphere and strong magnetic field and maintained at magnetic field of 0-30 tesla and temperature of 600-950 deg.c for 1-3 hr before the power source for the strong magnetic field and heating is turned off and the sample is cooled to room temperature inside the furnace. The present invention has effectively improved crystal grain connectivity and greatly raised clinical current structure of the magnesium diboride superconductor.

The invention relates to a nano-scale catalytic metal-ceramic bonding firing-free bitumen-impregnation-free environment-friendly slide plate and a preparation method thereof. The invention relates to the firing-free bitumen-impregnation-free environment-friendly slide plate and the process thereof. The invention relates to the field of a refractory material. The material comprises the raw materials of 25-40% granular first-grade alumina, 15-25% of tabular corundum, 6-12% of mullite, 6-15% of silicon carbide fine powder, 0.5-1% of clay, 0.5-2% of magnesium boride, 6-10% of zircon sand, 2-5% of aluminum powder, 1-3% of carbon black, 0.5-1.5% of boron carbide, 3-10% of alumina micro-powder, 0.5-1.5% of aluminum fiber, 1-3% of nano-powder ferrosilicon, 1-3% of iron silicon nitride, and 4-6% of a composite resin binder. The process comprises the following steps: resin, polycarboxylic acid and nano-powder are mixed to prepare the composite resin binder; the granular materials are dry-mixed; premixed powder and the binder are added; and mix grinding, aging, molding, drying, strapping, grinding, shell-applying, and packaging are carried out. The process does not require a firing step, such that energy is saved; and bitumen impregnation is not required, such that pollution is avoided. When the slide plate is applied in a continuous-casting large ladle, the slide plate can be used for continuous sliding more than 4 times. The slide plate can also be used in converter slag stopping.

The superconductive line material consists of the line core and the enveloping layer. The material of the line core is MgB2 possessing the superconductive properties. The enveloping layer is the metal cladding composed of low-carbon steel, nickel or tantalum. The preparing steps are as follows. According to mol ratio, Mg powder and B powder being mixed and ground is loaded into the metal tube. When the mixed powder is tight, the two ends of the tube are sealed, which is put into the oxygen free copper tube. Rotary swaging, rolling, vacuum annealing the wire obtain the MgB2 superconductive line. The invention possesses the features of good processability, fine crystal grain of MgB2, intensive connection of crystal grain of MgB2 and no phenomenon of rupture.

A magnesium boride thin film having a B-rich composition represented by the general formula of MgB_x (x=1 to 10) and a superconducting transition temperature of 10K or more has superior crystallinity and orientation and is used as a superconducting material. This thin film is formed by maintaining a film forming environment in a high vacuum atmosphere of 4×10⁻⁵ Pa or less, and simultaneously depositing Mg and B on a substrate maintained at a temperature of 200° C. or less so as to grow the film at a growth rate of 0.05 nm/sec or less. It is preferable to supply an Mg vapor and a B vapor into the film forming environment at an Mg/B molar ratio of 1/1 to 12/1.

The invention relates to a method for preparing magnesium boride superconducting material. The method for preparing the magnesium boride superconducting material is that magnesium powder and boron powder are respectively weighted according to 1:0.7-2.5 of molar ratio; adulterant which is one of citric acid and citrate is weighted according to 1:0.01-1 of mass ratio between the total mass of the magnesium powder and the boron powder and the mass of the adulterant is weighted; the magnesium powder, the boron powder and the adulterant are evenly mixed into mixing powder, then sintered under the protection of argon atmosphere at the temperature of 600-1200 DEG C and the product is obtained after the heat is preserved for 0.5-12 hours. The method has short preparation time, low reaction temperature, high efficiency and low cost and is especially suitable for industrial production; the critical current density of the magnesium boride superconducting material prepared by the method is increased remarkably and is especially very high in highfield, thereby being good for the application in highfield and having strong practicability.

A preparation method of a magnesium diboride-doped superconducting material comprises the following steps: respectively weighing magnesium powder and boron powder based on a mol ratio of 1:0.7-2.5; weighing a dopant based on the ratio of the total mass of the magnesium powder and the boron powder to the mass of the dopant of 1:0.01-1, wherein, the dopant is one of sorbic acid or sorbate; evenly mixing the magnesium powder, the boron powder and the dopant powder to obtain mixed powder; and sintering the mixed powder under the protection of argon atmosphere at the sintering temperature of 600 DEG C-1200 DEG C, and keeping the temperature for 0.5-12 hours, thus obtaining the superconducting material. The method has the advantages of short preparation time, low reaction temperature, high efficiency and low cost, and is especially suitable for industrialized production. The magnesium diboride superconducting material obtained by the method has obviously increased critical current density especially very high critical current density in a high magnetic field, which is beneficial to the application of the superconducting material to the high magnetic field; and the superconducting material has strong practicability.

The invention provides a method for manufacturing a magnesium boride superconductive belt material. The method comprises the following steps: A, uniformly distributing amorphous boron on a conductive substrate by adopting a coating method to form an amorphous boron layer with thickness of between 0.1 and 2.0mm; B, covering a magnesium or magnesium alloy flake with thickness of between 0.1 and 2.0mm on the boron layer, and rolling to form a magnesium-boron-substrate combination; C, putting the combination in the step B in a thermal treatment furnace, under the protection of argon atmosphere, heating to the temperature of between 550 and 800 DEG C, preserving the temperature for 0.1 to 3 hours, and cooling; D, coating metal, metallic oxide, silicon carbide or diamond like carbon film on the combination which is treated in the step C to serve as a protective layer to form a composite body; and E, cutting the composite body in the step D into long belts. The MgB2 superconductive belt prepared by the method has the advantages of good compactness and grain connection, high critical current density, uniform current density distribution and high fatigue life, and is suitable for commercial application. The method is simple, and is suitable for industrial production.

A method to fabricate boron nitride nanotubes incorporating magnesium diboride in their structure. In a first embodiment, magnesium wire is introduced into a reaction feed bundle during a BNNT fabrication process. In a second embodiment, magnesium in powder form is mixed into a nitrogen gas flow during the BNNT fabrication process. MgB₂ yarn may be used for superconducting applications and, in that capacity, has considerably less susceptibility to stress and has considerably better thermal conductivity than these conventional materials when compared to both conventional low and high temperature superconducting materials.

The invention discloses a preparation method of magnesium boride nanoparticles. According to liquid phase plasma technology, the magnesium boride nanoparticles are synthesized by reducing MgCl2 with borane in triethylphenylammonium bis (trifluoromethanesulfonyl) imine ionic liquid at room temperature. Compared with commercial magnesium boride, the prepared magnesium boride nanoparticles are largerin specific surface area and stronger in antibacterial effect. Compared with amikacin and vertilmicin sulfate, the magnesium boride nanoparticles prepared by the invention show stronger antibacterialactivity on enterobacter cloacae. Through the excellent antibacterial property of the enterobacter cloacae, the wide application of magnesium boride in the clinical treatment fields of hospital infected bacterial infectious diseases, such as skin soft tissue infection, urinary tract infection, respiratory tract infection and septicemia is expected to expand.

The invention relates to a controllable preparation method of a porous silicon material, which comprises the following steps: by taking silicon oxide SiOx as a main raw material and magnesium boride as a reducing agent, carrying out magnesiothermic reduction reaction to obtain a mixture of monatomic silicon, magnesium oxide and the like, and pickling to obtain the porous silicon material. The porous silicon material prepared by the preparation method disclosed by the invention retains typical morphological characteristics of an original material and shows a rich mesoporous structure. The unique adjustable porous structure not only can effectively relieve mechanical strain caused by volume change, but also is beneficial to improving transmission kinetics in an electrochemical reaction process. Meanwhile, the method has the advantages of being simple in preparation process, controllable in reaction, universal in strategy and the like. The micron/nano porous silicon material prepared by the method has potential application prospects in the field of new energy such as lithium ion batteries and the like.