High-strength aluminum alloy and process for producing same

摘要

A high-strength aluminum alloy material having a chemical composition which includes Zn: more than 7.2% (mass %, the same applies hereafter) and 8.7% or less, Mg: 1.3% or more and 2.1% or less, Cu: 0.01% or more and 0.10% or less, Zr: 0.01% or more and 0.10% or less, Cr: less than 0.02%, Fe: 0.30% or less, Si: 0.30% or less, Mn: less than 0.05%, Ti: 0.001% or more and 0.05% or less, the balance being Al and unavoidable impurities, is provided. It has a proof stress of 350 MPa or more, and a metallographic structure formed of a recrystallized structure, and L* and b* values, as defined in JIS Z8729 (ISO 7724-1), are 85 or more and 95 or less and 0 or more and 0.8 or less, respectively, as measured after anodization using a sulfuric acid bath.

主权项

1. An aluminum alloy material, comprising in mass percent:
Zn: more than 7.2% and 8.7% or less, Mg: 1.3% or more and 2.1% or less, Cu: 0.01% or more and 0.10% or less, Zr: 0.01% or more and 0.10% or less, Cr: less than 0.02%, Fe: 0.30% or less, Si: 0.30% or less, Mn: less than 0.05%, Ti: 0.001% or more and 0.05% or less, the balance being Al and unavoidable impurities; wherein the aluminum alloy material has a proof stress of 350 MPa or more, and a metallographic structure consisting essentially of a recrystallized structure, and the aluminum alloy material has a composition and microstructure capable of achieving an L* value, as defined in ISO 7724-1, of 85-95 and a b* value, as defined in ISO 7724-1, of 0-0.8, as measured after anodization of the aluminum alloy material in a sulfuric acid bath.