Sumitomo Electric Industries, Limited

Masayuki Nishizawa

Nozomu Kawabe

Nobuyuki Mori

Koji Mori

Nobuyuki Okuda

Motonori Nakamura

Yukihiro Oishi

Atsushi Kimura

Masatada Numano

Takayasu Sugihara

Ryuichi Inoue

Masahiro Yamakawa

Osamu Mizuno

Junichi Matsumoto

Kohji Inokuchi

The invention offers a magnesium alloy sheet having excellent warm plastic formability, a production method thereof, and a formed body produced by performing warm plastic forming on this sheet. The magnesium alloy sheet is produced by giving a predetermined strain to a rolled sheet RS that is not subjected to a heat treatment aiming at recrystallization. The sheet is not subjected to the foregoing heat treatment even after the giving of a strain. The strain is given through the process described below. A rolled sheet RS is heated in a heating furnace. The heated rolled sheet RS is passed between rollersto give bending to the rolled sheet RS. The giving of a strain is performed such that the strain-given sheet has a half peak width of 0.20 deg or more and 0.59 deg or less in a (0004) diffraction peak in monochromatic X-ray diffraction. The alloy sheet exhibits high plastic deformability by forming continuous recrystallization during warm plastic forming through the use of the remaining strain.

Magnesium alloy sheet

A magnesium alloy structural member having excellent corrosion resistance is provided. The magnesium alloy structural member includes a magnesium alloy substrate that contains more than 7.5% by mass of Al and an anticorrosive layer formed on a surface of the substrate by chemical conversion treatment. The substrate contains a precipitate, typically, particles dispersed therein. The particles are made of an intermetallic compound containing at least one of Al and Mg and have an average particle size of 0.05 &#x3bc;m or more and 1 &#x3bc;m or less. The total area of the particles accounts for 1% by area or more and 20% by area or less. The anticorrosive layer includes a lower sublayer and a surface sublayer on the substrate in this order. The surface sublayer is denser than the lower sublayer. The substrate of the magnesium alloy structural member has high corrosion resistance because of a high Al content. The magnesium alloy structural member has excellent corrosion resistance because of the dense sublayer on the front side of the anticorrosive layer, which prevents a corrosive liquid from reaching the substrate. The porous lower sublayer can reduce the tendency of the anticorrosive layer to detach from the substrate, for example, upon impact and allows the magnesium alloy structural member to retain high corrosion resistance.

Magnesium alloy structural member

A magnesium alloy material having excellent impact resistance is provided. The magnesium alloy material is composed of a magnesium alloy that contains more than 7.5% by mass of Al and has a Charpy impact value of 30 J/cmor more. Typically, the magnesium alloy material has an elongation of 10% or more at a tension speed of 10 m/s in a high-speed tensile test. The magnesium alloy is composed of a precipitate, typically made of an intermetallic compound containing at least one of Al and Mg, and contains particles having an average particle size of 0.05 &#x3bc;M or more and 1 &#x3bc;m or less dispersed therein. The total area of the particles accounts for 1% by area or more and 20% by area or less. The magnesium alloy material containing fine precipitate particles dispersed therein has high impact absorption capacity through dispersion strengthening and has excellent impact resistance.

Magnesium alloy material

Growing community of inventors

Osaka, Japan

Masayuki Nishizawa