Abstract: A prototype aluminum mold for stampers that is used to manufacture stampers having a fine irregular surface structure on the surface thereof and containing aluminum and magnesium, wherein the content of magnesium is 0.1% by mass to 3% by mass, the content of silicon is 100 ppm by mass or less, the total content of elements other than aluminum and magnesium is 500 ppm by mass or less, and the number of magnesium silicide particles having an equivalent diameter of 10 nm or more on the surface of the prototype aluminum mold for stampers is 10/1000 ?m2 or less.

Abstract: The present invention provides an aluminum-alloy automotive underbody part having adequate strength even when using a part forged from an aluminum alloy casting material and an effective method for manufacturing said underbody part. The present invention pertains to an automotive underbody part characterized in being an aluminum alloy forged part in which the average inverse of the Schmid factor, calculated based on the crystal orientation in the direction of load stress in the maximum stress area when external force is applied, is 2.3 or more.

Abstract: The invention relates to a stamper in which an oxide film having a fine concave-convex structure made up of a plurality of fine pores having an aspect ratio represented by [the depth of the fine pores/the average interval between the fine pores] of 1 to 4 is formed on the surface of an aluminum base material which is made of aluminum having a content of Ti of 150 ppm to 500 ppm, a content of B or C of 1 ppm to 50 ppm and a purity of 99.9% or more. According to the invention, it is possible to provide a low-cost stamper in which the emergence of a pattern derived from the traces of crystal grains on the surface of the oxide film is suppressed, an article having a favorable appearance, which is manufactured using the above stamper, and a method for manufacturing the above.

Abstract: The present invention relates to an aluminum die base material for a stamper having a component composition that contains 0.5% by weight to 3.0% by weight of Mg, the total amount of elements other than Mg, including unavoidable impurities, is 500 ppm or less, and the remainder is composed of Al, and a forged structure in which the average crystal grain size is 1000 ?m or less and the surface area ratio of second phase particles is 0.10% or less. According to the present application, a stamper can be provided in which, together with the crystal grain size of the aluminum being refined, the formation of second phase particles is inhibited, surface irregularities attributable to mirrored surface polishing are reduced, and a uniform relief pattern is formed by anodic oxidation treatment.

Abstract: Disclosed herein are a stamper which has anodized alumina formed on the surface thereof and which will not cause macroscopic unevenness or color unevenness on the transcribed surface; a method for producing the same; and a method for producing a molded material without macroscopic unevenness or color unevenness on the transcribed surface thereof by using such a stamper. The stamper includes alumina which has a microasperity structure and which is formed by anodization on the surface of a prototype aluminum mold having an aluminum purity of 99.5% or more, an average crystal-grain diameter of 1 mm or less, and an arithmetic mean surface roughness Ra of 0.05 ?m or less. The use of this stamper enables the production of a molded material which does not have macroscopic unevenness or color unevenness on the transcribed surface thereof and which is suitable for use as an antireflection article and the like.

Abstract: A prototype aluminum mold for stampers that is used to manufacture stampers having a fine irregular surface structure on the surface thereof and containing aluminum and magnesium, wherein the content of magnesium is 0.1% by mass to 3% by mass, the content of silicon is 100 ppm by mass or less, the total content of elements other than aluminum and magnesium is 500 ppm by mass or less, and the number of magnesium silicide particles having an equivalent diameter of 10 nm or more on the surface of the prototype aluminum mold for stampers is 10/1000 ?m2 or less.

Abstract: Provided is an Al alloy member with an excellent mechanical strength that is sufficient for use in large-scale manufacturing apparatuses. The Al alloy member is characterized in that, in mass %, Mg concentration is 5.0% or less, Ce concentration is 15% or less, Zr concentration is 0.15% or less, the balance comprises Al and unavoidable impurities, the elements of the unavoidable impurities are respectively 0.01% or less, and the Vickers hardness of the Al alloy member is greater than 30.

Abstract: The invention relates to a stamper in which an oxide film having a fine concave-convex structure made up of a plurality of fine pores having an aspect ratio represented by [the depth of the fine pores/the average interval between the fine pores] of 1 to 4 is formed on the surface of an aluminum base material which is made of aluminum having a content of Ti of 150 ppm to 500 ppm, a content of B or C of 1 ppm to 50 ppm and a purity of 99.9% or more. According to the invention, it is possible to provide a low-cost stamper in which the emergence of a pattern derived from the traces of crystal grains on the surface of the oxide film is suppressed, an article having a favorable appearance, which is manufactured using the above stamper, and a method for manufacturing the above.

Abstract: The present invention relates to an aluminum die base material for a stamper having a component composition that contains 0.5% by weight to 3.0% by weight of Mg, the total amount of elements other than Mg, including unavoidable impurities, is 500 ppm or less, and the remainder is composed of Al, and a forged structure in which the average crystal grain size is 1000 ?m or less and the surface area ratio of second phase particles is 0.10% or less. According to the present application, a stamper can be provided in which, together with the crystal grain size of the aluminum being refined, the formation of second phase particles is inhibited, surface irregularities attributable to mirrored surface polishing are reduced, and a uniform relief pattern is formed by anodic oxidation treatment.

Abstract: Provided is an Al alloy member with an excellent mechanical strength that is sufficient for use in large-scale manufacturing apparatuses. The Al alloy member is characterized in that, in mass %, Mg concentration is 5.0% or less, Ce concentration is 15% or less, Zr concentration is 0.15% or less, the balance comprises Al and unavoidable impurities, the elements of the unavoidable impurities are respectively 0.01% or less, and the Vickers hardness of the Al alloy member is greater than 30.

Abstract: Disclosed herein are a stamper which has anodized alumina formed on the surface thereof and which will not cause macroscopic unevenness or color unevenness on the transcribed surface; a method for producing the same; and a method for producing a molded material without macroscopic unevenness or color unevenness on the transcribed surface thereof by using such a stamper. The stamper includes alumina which has a microasperity structure and which is formed by anodization on the surface of a prototype aluminum mold having an aluminum purity of 99.5% or more, an average crystal-grain diameter of 1 mm or less, and an arithmetic mean surface roughness Ra of 0.05 ?m or less. The use of this stamper enables the production of a molded material which does not have macroscopic unevenness or color unevenness on the transcribed surface thereof and which is suitable for use as an antireflection article and the like.