Sumitomo Chemical Company, Limited

Aisin Keikinzoku Co., Ltd.

Inter-University Research Institute Corporation High Energy Accelerator Research Organization

Hiroshi Tabuchi

Akihiko Takahashi

Ichiro Tanaka

Shinji Fujiwara

Masahide Mohri

Tomoo Yoshida

Karin Shibata

Takayuki Tomaru

Hiroaki Hoshikawa

Kenichi Sasaki

Tomohiro Megumi

Hidetoshi Takagi

Hidemitsu Shimizu

A magnetic shielding material which can decrease the thickness by having excellent conductivity even at low temperatures of, for example, 77 K or lower, in a strong magnetic field of a magnetic flux density of 1 T or more is provide. A magnetic shielding material to be used at low temperatures of 77 K or lower in the magnetic field of a magnetic flux density of 1 T or more, comprises aluminum having a purity of 99.999% by mass or more.

Magnetic shielding material for superconducting magnet

Provided is a process for producing a boron added silicon (purified silicon) in an energy saving mode from a reduced silicon obtained by reducing a silicon halide with a metal aluminium. The production process of the invention comprises reducing a silicon halide with a metal aluminium to give a reduces silicon, heating and melting the resulting reduced silicon, and adding boron thereto followed by solidification for purification under the condition of a temperature gradient provided in one direction in a mold. Preferably, after washed with an acid, the reduced silicon is heated and molten, and boron is added thereto. After the reduced silicon is heated and molten under reduced pressure, boron is added thereto. After heated and molten, the reduced silicon is purified by solidification in one direction, then heated and molten, and thereafter boron is added thereto.

Process for producing boron added purified silicon

A method includes: preparing a molten aluminum alloy consisting of 0.3-0.8 mass % Mg, 0.5-1.2 mass % Si, 0.3 mass % or more excess Si relative to the MgSi stoichiometric composition, 0.05-0.4 mass % Cu, 0.2-0.4 mass % Mn, 0.1-0.3 mass % Cr, 0.2 mass % or less Fe, 0.2 mass % or less Zr, and 0.005-0.1 mass % Ti, with the balance being aluminum and unavoidable impurities; casting the alloy into a billet at a speed of 80 mm/min or more and a cooling rate of 15&#xb0; C./sec or more; extruding the billet into an extruded product; water cooling the product immediately after extrusion at 500&#xb0; C./min or more; and artificially aging the product, thereby yielding an extruded product with fatigue strength of 140 MPa or more, fatigue ratio of 0.45 or more, an interval between striations on a fatigue fracture surface of 5.0 &#x3bc;m or less, and a maximum length of Al&#x2014;Fe&#x2014;Si crystallized products of 10 &#x3bc;m or less.

Al-Mg-Si aluminum alloy extruded product exhibiting excellent fatigue strength and impact fracture resistance

A method for purifying aluminum to provided which comprises the steps of maintaining aluminum as a starting material in a molten condition in N&plus;1 vessels; wherein N&plus;1 vessels for molten aluminum and N cooling bodies are provided which are immersed in molten aluminum in the vessels and upon which highly purified aluminum is crystallized on the surfaces thereof. The N&plus;1 vessels are arranged sequentially from 1-st to (N&plus;1)-th and the N cooling bodies are sequentially arranged from 1-st to N-th, respectively, and the vessels and cooling bodies are moved relative to each other.

Method for purifying aluminum

A powdery .alpha.-alumina having an alumina purity of at least 99.8 wt. %, a sodium content of 40 ppm or less and an iron content of 20 ppm or less, which is obtained by grinding aluminum hydroxide which is produced by the Bayer process or a transition alumina which is obtained by precalcining aluminum hydroxide produced by the Bayer process, and calcining the aluminum hydroxide or transition alumina in an atmosphere containing 1 vol. % or more of a hydrogen chloride gas, or an atmosphere containing 1 vol. % or more of a chlorine gas and 0.1 vol. % or more of steam, at a temperature of 600 to 1400.degree. C.

Alpha-alumina and method for producing same

The present invention provides a method for producing high purity aluminum by immersing a cooling body in molten aluminum, and forming and growing crystals of the high purity aluminum on the cooling body by rotating the molten aluminum around the cooling body and introducing bubbles of a gas into the rotating molten aluminum.

Method for producing high purity aluminum

The present invention provides a method for producing high purity aluminum by immersing a cooling body in molten aluminum, and forming and growing crystals of the high purity aluminum on the cooling body by rotating the cooling body and introducing bubbles of a gas into the rotating molten aluminum by the rotation of the cooling body.

A metal matrix composite comprising 2 to 80 volume % of .alpha.-alumina powder as a reinforcement, said .alpha.-alumina powder comprises polyhedral primary particles substantially having no fracture surface, D50 of .alpha.-alumina powder is 0.1 .mu.m to 50 .mu.m and a ratio of D50 to D10 is not more than 2, wherein D10 and D50 are particle sizes at 10% and 50% cumulation from the smallest particle side of a weight cumulative particle size distribution, respectively, and a process for producing the metal matrix composite which comprises infiltrating a molten metal into the .alpha.-alumina powder under pressure or non-pressure.

Metal matrix composite and process for producing the same

A process of producing a powder of a transition-metal boride includes producing metal boride particles in a molten metal by contacting a molten salt, to which at least one boron compound was added, with the molten metal containing a transition-metallic element selected from the Groups IV and V of the Periodic Table at an atomic ratio of elemental boron to transition-metallic element from 0.5 to 4.0, while maintaining a contact temperature which is not lower than the melting point of the molten metal and which is less than 1000.degree. C., and recovering the particles from the molten metal. According to the present invention, fine powders of the transition-metal boride which contain few agglomerated particles may be easily obtained using relatively inexpensive feed materials, such as the boron oxides, at a low temperature less than 1000.degree. C. without the necessity of a grinding step.

Process for producing powders of transition metal boride

Polyhedral .alpha.-alumina particles having a particle size on the order of a micrometer and high purity are prepared by maintaining a compression molded aluminum material having, on its surface, a binary compound of aluminum and oxygen atoms or a ternary compound of aluminum, oxygen and hydrogen atoms in an aluminum melt.

Growing community of inventors

Tsukuba, Japan

Hiroshi Tabuchi