Abstract: An aluminum alloy sheet combining excellent press formability and spot weldability is disclosed. A chromate film of about 1.0 to 50.0 mg/m.sup.2 expressed in terms of metallic chromium is formed as a first layer on an aluminum alloy sheet, and an organic resin film containing about 60-95% by weight of organic lubricant and having a thickness of 0.02 to 0.90 .mu.m in terms of dry thickness is formed as a second layer on the chromate film. As the organic lubricant, a high-density polyethylene having a mean molecular weight of about 900 to 15,000 and a density of about 0.93 g/ml or more is preferable. This aluminum alloy sheet can be effectively used for automobile body applications.

Abstract: A method including preparing an aluminum scrap containing a total of about 0.3 to 2.0 wt % of Fe and Si; melting and then adjusting the material composition so as to attain an Mg content of about 3 to 10 wt % or a composition further containing at least one of the elements Cu, Mn, Cr, Zr and Ti, each in the amount of 0.02 to 0.5 wt %; subjecting the material to casting, hot rolling, cold rolling and continuous annealing to obtain an aluminum alloy sheet having a tensile strength of about 31 kgf/mm.sup.2 or more; and applying a lubricant surface coating to impart a coefficient of friction of not more than about 0.11.

Abstract: A surface-treated aluminum material comprising an aluminum or aluminum alloy substrate, a chromate film deposited on the substrate, and an organic resin mixture film deposited on the chromate film is provided. The chromate film is deposited to a coating weight of from 5 to 100 mg/m.sup.2 calculated in terms of elementary chromium on the aluminum substrate. The organic resin mixture film is deposited to a dry film thickness of from 0.05 to 3.0 .mu.m, and comprises (a) 100 parts by weight of an organic resin, (b) 0.5 to 40 parts by weight of a powder lubricant having an average particle size of from 0.05 to 20 .mu.m, said average particle size being in the range of from 1.0 to 10 folds of the dry film thickness, and (c) 1.0 to 40 parts by weight of electroconductive finely divided particles having an average particle size in the range of from 0.05 to 5 .mu.m, said average particle size being in the range of from 1.0 to 2 folds of the dry film thickness.

Abstract: The invention provides an aluminum alloy sheet having improved formability, an elongation of at least 30%, a sliding frictional resistance of up to 0.13 and minimized surface pressure dependency of sliding frictional resistance, comprising an aluminum alloy substrate containing at least 4 wt % of Mg and a Fe rich plating layer on a surface thereof in a coating weight of 1 to 50 g/m.sup.2. Also provided is a bake hardenable, surface treated aluminum alloy sheet having improved formability, an elongation of at least 25%, a sliding frictional resistance of up to 0.13 and minimized surface pressure dependency of sliding frictional resistance, comprising a bake hardenable aluminum alloy substrate containing Mg and Si in an amount of at least 0.4 wt % calculated as Mg.sub.2 Si and a Fe rich plating layer on a surface thereof in coating weight of 1 to 50 g/m.sup.2. By forming a zincate layer as an undercoat below the Fe rich plating layer, the plating adhesion is further improved.

Abstract: An aluminum alloy for magnetic disc substrate excellent in platability is disclosed, which is characterized in that not less than 0.010 wt. % and under 0.03 wt. % of Cu, not less than 2 wt. % and not more than 6 wt. % of Mg and not less than 0.05 wt. % and not more than 2.0 wt. % of Zn are contained, further one or more of over 0.01 wt. % and under 0.05 wt. % of Mn and over 0.01 wt. % and under 0.05 wt. % of Cr are contained, and, as impurity elements, Si, Fe, Ti and other individual unavoidable element are regulated to be not more than 0.1 wt. %, not more than 0.1 wt. %, not more than 0.02 wt. % and not more than 0.02 wt. %, respectively. Zr may be contained additionally in amounts of not less than 0.005 wt. % and under 0.05 wt. %.

Abstract: An aluminum alloy for the substrate of magnetic disk is disclosed, wherein 2 to 6 wt % of Mg and further either one or two of Cu within a range of 0.12 to 2.0 wt % and Zn within a range of 0.28 to 7.0 wt % are contained, and the remainder comprises of Al and inevitable impurities.

Abstract: An anodized memory disk substrate is disclosed, which is characterized in having an anodic film having excellent heat resistance and hardness and having a thickness of not less than 3 .mu.m on the surface of aluminum or an aluminum alloy substrate imparted thereto by means of chromic acid-sulfuric acid mixture. The method described therefor is that, after the formation of anodic film having a film thickness of not less than 4 .mu.m on the surface of substrate, polishing is carried out so as to leave behind the anodic film having a film thickness of at least 3 .mu.m. Heat treatment may be made before or after the polishing.