National Institute for Materials Science

Toyota Jidosha Kabushiki Kaisha

Kobe University

Toshiji Mukai

Hidetoshi Somekawa

Alok Singh

Yoshiaki Osawa

Akira Kato

Kazuhiro Hono

Akiko Yamamoto

Sachiko Hiromoto

Norio Maruyama

Tetsuya Shoji

Tadanobu Inoue

Taisuke Sasaki

Kota Washio

Takumi Fukumoto

Eisei Gu

Naoko Ikeo

Hikaru Yabuuchi

Tomoyuki Honma

A device for fixing biological soft tissue is endowed with strength and deformation performance for being used as a device for coupling biological soft tissue that has been cut or separated due to an incision or the like during a surgical procedure, and is completely degraded in vivo and discharged after adhesion of the soft tissue or after healing of the incision tissue. The device is composed of a ternary Mg alloy material of Mg&#x2014;Ca&#x2014;Zn. In the Mg alloy material, the Ca and Zn are contained within the solid-solubility limit with respect to the Mg. The remainder is composed of Mg and unavoidable impurities. The Zn content is 0.5 at % or less. The Ca and Zn content has a relationship of Ca:Zn=1:x (where x is 1 to 3) by atom ratio. The crystal grain structure is equiaxed, the crystal grain size according to linear intercept being 30 to 250 &#x3bc;m.

Device for fixing biological soft tissue, and method for producing same

Provided is an Mg alloy and a method for producing same able to demonstrate high strength without requiring an expensive rare earth element (RE). The high-strength Mg alloy containing Ca and Zn within a solid solubility limit and the remainder having a chemical composition comprising Mg and unavoidable impurities is characterized in comprising equiaxial crystal particles, there being a segregated area of Ca and Zn along the (c) axis of a Mg hexagonal lattice within the crystal particle, and having a structure in which the segregated area is lined up by Mgatomic spacing in the (a) axis of the Mg hexagonal lattice. The method for producing the high-strength Mg alloy is characterized in that Ca and Zn are added to Mg in a compounding amount corresponding to the above composition and, after homogenization heat treating an ingot formed by dissolution and casting, the above structure is formed by subjecting the ingot to hot processing.

High strength Mg alloy and method for producing same

The quasicrystal phase and/or quasicrystal-like phase particles, which is composed of the Mg&#x2014;Zn&#x2014;Al, are dispersed into Mg-base alloy material for strain working. The microstructure in this material does not include the dendrite structure, and the size of the magnesium matrix is 40 &#x3bc;m or less than 40 &#x3bc;m. The present invention shows that the quasicrystal phase and/or quasicrystal-like phase is able to form by addition of the Zn and Al elements except for the use of rare earth elements. In addition, the excellent trade-off-balancing between strength and ductility and reduction of the yield anisotropy, which are the serious issues for the wrought processed magnesium alloys, is able to obtain by the microstructure controls before the strain working process.

Mg-base alloy

A magnesium-based medical device which can adjust a degree of corrosion within a wide range of period such that the device can maintain a sufficient strength only during a desired period and disappears within a desired period thereafter and a manufacturing method thereof are provided. A magnesium-based medical device of the present invention is a magnesium-based medical device in which a base material is made of magnesium or a magnesium alloy, wherein a corrosion-resistant film is formed on a surface of the base material, and variation in surface hardness of the formed corrosion-resistant film in the in-plane direction is less than 21 in terms of a dispersion value of Vickers hardness.

Magnesium-based medical device and manufacturing method thereof

An object of the invention is to provide a magnesium alloy having high strength and sufficient formability. A magnesium alloy mainly contains magnesium and has high tensile strength and high compression strength. The crystal grain structure of the alloy has a high angle grain boundary, and the inside of the crystal grain surrounded by the high angle grain boundary is composed of subgrains.

Magnesium alloy

Provided is a Mg alloy, in which precipitated particles are dispersed and which has enhanced tensile strength regardless of the size of the magnesium matrix grains therein.

Mg alloy

An Mg alloy provided with high strength and high ductility by matching the strength and ductility in tensile deformation and compressive deformation at the same levels is provided. The Mg alloy of the present invention is characterized by having a chemical composition consisting of Y: 0.1 to 1.5 at % and a balance of Mg and unavoidable impurities and having a microstructure with high Y regions with Y concentrations higher than an average Y concentration distributed at nanometer order sizes and intervals. The present invention further provides an Mg alloy characterized by having a chemical composition consisting of Y: more than 0.1 at % and a valance of Mg and unavoidable impurities, having a microstructure with high Y regions with Y concentrations higher than an average Y concentration distributed at nanometer order sizes and intervals and having an average recrystallized grain size within the range satisfying the following formula 1:&#x2212;0.87+1.10&#x3c;log&#x3c;1.14+1.48,&#x2003;&#x2003;formula 1:where c: Y content (at %) andd: average recrystallized grain size (&#x3bc;m).

Mg alloy and method of production of same

An Mg-base alloy shows that an Mg-base alloy, which is added Zn and Al to magnesium, has a composition represented by (100-a-b) wt % Mg-a wt % Al-b wt % Zn, and satisfying 0.5&#x2266;b/a. The alloy can reduce yield anisotropy, which is a serious problem for the wrought magnesium alloy, while maintaining a high strength property. The alloy is produced by additive elements, such as Zn and Al, which are easily obtained in place of rare earth elements.

Mg-based alloy

As a novel biodegradable metallic material the degradation speed of which in vivo can be controlled over a broad scope while achieving desired mechanical properties such as strength, work hardening and ductility without restricting the shape of an implant device, it is intended to provide a magnesium-based biodegradable metallic material which comprises Mg containing Mg as the major composition and having a concentration of inevitable impurities equal to or less than 0.05 atomic %, is free from precipitates or intermetallic compounds, and has an average grain size being regulated to equal to or less than &#xbc; of the minimum part of the material.

Magnesium-based biodegradable metallic material

Disclosed is a binary aluminum alloy powder sintered material which comprises aluminum and iron, which has a completely crystalline microstructure comprising an aluminum matrix and an &#x3b1;-Al phase and at least any one phase of an AlFe phase or an AlFephase mixed in the aluminum matrix as nanocrystalline phases, and which has an extremely high strength and a well-balanced high ductility, though being free from any rare earth element.

Sintered binary aluminum alloy powder sintered material and method for production thereof

A magnesium alloy exhibiting high strength and high ductility, characterized in that it comprises 0.03 to 0.54 atomic % of certain solute atoms belonging to 2 Group, 3 Group or Lanthanoids of the Periodic Table and having an atomic radius larger than that of magnesium and the balanced amount of magnesium, and has a fine crystal grain structure wherein solute atoms having an average crystal grain diameter of 1.5 &#x3bc;m or less and being unevenly present in the vicinity of crystal grain boundaries at a concentration being 1.5 to 10 times that within crystal grains, wherein an atom selected from the group consisting of Ca, Sr, Ba, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Th, Dy, Ho, Er, Tm, Yb and Lu can be used as the above solute atom; and a method for producing the magnesium alloy. The above magnesium alloy is novel and achieves high strength and high ductility at the same time.

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Ibaraki, Japan

Toshiji Mukai