Patent ID: 11933553
Assignee: NOVELIS INC.
Field: Materials, metallurgy (Chemistry)
Classification: CPC F  B  C | IPC B  C  F

Claim 0:
1. A process of making a fin stock aluminum alloy sheet, comprising:
direct chill casting into an ingot an aluminum alloy comprising 0.9-1.2 wt. % Si, 0.3-0.5 wt. % Fe, 0.20-0.40 wt. % Cu, 1.25-1.5 wt. % Mn, 0-0.1 wt. % Mg, 2.0-3.0 wt. % Zn, less than 0.01 wt. % Zr, less than 0.01 wt. % Cr, and Al and impurities at ≤0.15 wt. %, wherein each impurity is below 0.05 wt. %;
hot rolling the ingot into a hot rolled sheet;
cold rolling the hot rolled sheet into an intermediate thickness sheet;
inter-annealing the intermediate thickness sheet at 200-400° C.; and,
cold rolling the intermediate thickness sheet to achieve a % cold work (% CW) of 20 to 40%, resulting in the fin stock aluminum alloy sheet having a thickness of 70-100 μm.