Novelis, Inc.

John Andrew Ward

Jonathan Ball

Martin Philip Amor

There is disclosed a process for producing an aluminium alloy sheet, which comprises subjecting a surface of the sheet to anodising conditions to form on the surface an aluminium oxide barrier layer of thickness 10 to 50 nm and treating the oxide layer with an aqueous solution of alkali to remove the layer, thereby leaving a roughened surface on the alloy sheet.

Aluminium alloy sheet with roughened surface

There is disclosed an Al alloy suitable for processing into a lithographic sheet, the alloy having a composition in wt %: Fe up to 0.4; Si up to 0.25; Ti up to 0.05; Cu up to 0.05; Zr up to 0.005; Cr up to 0.03; Ni up to 0.006; V up to 0.03; Zn up to 0.008 to 0.15; Mg up to 0.30; Mn up to 1.5. Unavoidable impurities up to 0.05 wt % total Al balance. The alloy allows production of the required surface for lithographic sheet over a wide range of process conditions.

Growing community of inventors

Leamington Spa, United Kingdom

John Andrew Ward