Yoshida Kogyo K.k.

Yoshida Kogyo Kabushiki Kaisha

Ykk Corporation

Kazuo Aikawa

Mutsuo Hasegawa

Junichi Nagahora

Katsuyuki Nagata

Katsumasa Ohtera

Keiko Yamagata

Akihisa Inoue

Tsuyoshi Masumoto

Hideki Takeda

Hatsuo Hirono

Masatake Tsuboi

Katsuyuki Taketani

Madoka Nakajima

Makoto Kato

Satoshi Ishikura

Shinji Hayashi

Toshikazu Imaoka

Disclosed are a method for electrolytically coloring an aluminum material which is capable of coloring an anodic oxide film in a gray color and a gray-colored aluminum material obtained thereby. In a method for electrolytically coloring an aluminum material having the anodic oxide film formed on the surface thereof in an electrolytic coloring solution containing an inorganic metal salt, a strongly acidic electrolytic coloring solution containing sulfuric acid, stannous sulfate, nickel sulfate, and ammonium sulfate and having a pH of not more than 2.5 is used as the electrolytic coloring solution. Preferably the electrolytic coloring solution contains sulfuric acid at a concentration in the range of 3 to 30 g/liter, stannous sulfate at a concentration in the range of 0.1 to 3.0 g/liter, nickel sulfate at a concentration in the range of 10 to 100 g/liter, and ammonium sulfate at a concentration in the range of 20 to 100 g/liter. By this method, a gray-colored aluminum material possessed of an anodic oxide film colored in an achromatic or substantially achromatic gray color is obtained.

Method for electrically coloring aluminum material and gray-colored

The present invention provides high strength magnesium-based alloys which are composed a fine crystalline structure, the alloys having a composition represented by the general formula (I) Mg.sub.a X.sub.b ; (II) Mg.sub.a X.sub.c M.sub.d, (III) Mg.sub.a X.sub.c Ln.sub.e ; or (IV) Mg.sub.a X.sub.c M.sub.d Ln.sub.e (wherein X is one or more elements selected from the group consisting of Cu, Ni, Sn and Zn; M is one or more elements selected from the group consisting of Al, Si and Ca; Ln is one or more elements selected from the group consisting of Y, La, Ce, Nd and Sm or a misch metal of rare earth elements; and a, b, c, d and e are atomic percentages falling within the following ranges: 40.ltoreq.a.ltoreq.95, 5.ltoreq.b.ltoreq.60, 1.ltoreq.c.ltoreq.35, 1 .ltoreq.d.ltoreq.25 and 3.ltoreq.e.ltoreq.25). Since the magnesium-based alloys have a superior combination of properties of high hardness, high strength and good processability, they are very useful in various industrial applications.

High strength magnesium-based alloys

Disclosed is a corrosion resistant aluminum-based alloy which is composed of a compound having a composition consisting of the general formula: Al.sub.a M.sub.b Mo.sub.c X.sub.d Cr.sub.e wherein: M is one or more metal elements selected from the group consisting of Ni, Fe, Co, Ti, V, Mn, Cu and Ta; X is Zr or a combination of Zr and Hf; and a, b, c, d and e are, in atomic percentages; 50%.ltoreq.a.ltoreq.89%, 1%.ltoreq.b.ltoreq.25%, 2%.ltoreq.c.ltoreq.15%, 4%.ltoreq.d.ltoreq.20% and 4%.ltoreq.e.ltoreq.20%, the compound being at least 50% by volume composed of an amorphous phase. The Al-based alloy exhibits a very high corrosion resistance in severe corrosive environments, such as hydrochloric acid solution or sodium hydroxide solution, due to the formation of a highly passivative protective film. Therefore, the alloy exhibits a good durability in long services under such severe corrosive environments.

Corrosion resistant aluminum-based alloy

The present invention provides a corrosion resistant aluminum-based alloy consisting of a compound which has a composition represented by the general formula:

The invention provides a novel and improved method according to which the surface of a shaped article of aluminum or an aluminum-based alloy is provided with decorative streak patterns electrolytically engraved in the surface which can be subsequently colored to increase the decorative effect with uniform distribution over whole surface of the aluminum article. The method comprises first subjecting the anodically oxidized aluminum article to an anodic direct current electrolysis in an electrolytic solution containing a specified electrolyte and then carrying out a cathodic direct current electrolysis with the aluminum article and the counterelectrode kept as before in the same electrolytic solution as used in the first anodic direct current electrolysis with reversed polarity to give uniformly distributed streak patterns on the surface of the aluminum article. The surface of the aluminum article thus provided with the streak patterns is subsequently anodized to enhance the corrosion resistance and then subjected to a coloring treatment.

Method for forming decorative colored streak patterns on the surface of

Aluminum or aluminum alloy is first anodized to form an oxide film thereon. With the pores in this oxide film unsealed, the basis metal is then electrolyzed by use of alternating current at a preselected starting voltage, and this voltage is lowered at least once before completion of the electrolytic coloring of the basis metal. The electrolytic solution in which the electrolysis is effected contains either at least three metallic salts or at least two metallic salts and a strong reducing compound.

Process for electrolytically coloring aluminum and aluminum alloys

Aluminum or aluminum alloy is first anodized to form an oxide film thereon. Before being colored electrolytically in an electrolytic solution, the anodized basis metal is made anodic in this solution, and direct current is passed therethrough. The basis metal is then electrolyzed in the same solution by use of alternating current for actual coloring operation. The electrolytic solution in use contains at least two metallic salts, together with or without a strongly reducing compound.

Aluminum or aluminum alloy is first anodized to form an oxide film thereon. With the pores in this oxide film unsealed, the basis metal is then electrolyzed in an electrolytic solution containing at least two metallic salts and a strongly reducing compound, by use of alternating current at potentials not more than about 15 volts.

Aluminum or aluminum alloy is first anodized to form an oxide film thereon. The anodized basis metal is electrolyzed by use of alternating current in an electrolytic solution which is prepared by adding formaldehyde, usually as formalin, and a thiosulfate to an acid solution of stannous sulfate. The acid solution of stannous sulfate can be prepared by dissolving stannous sulfate in an aqueous solution of sulfuric acid, sulfamic acid, tartaric acid or the like.

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Namerikawa, Japan

Kazuo Aikawa