High strength aluminum base alloy
AssigneeNorthwest Aluminum Company
InventorS. Craig Bergsma
Life of this patent
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Abstract
An improved Si—Cu—Mg—Al base alloy suitable for forming in the semi-solid condition into members such as vehicular members having improved properties.
Claims14
A method of forming an aluminum base alloy member having a globular microstructure contained in a lower melting eutectic matrix, the method comprising the steps of:
- (a) providing a body of a semi-solid aluminum base alloy comprising 3.5 to 4.9 wt. % Si, 3.6 to 5 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance aluminum, incidental elements and impurities;
- (b) providing a mold for said member;
- (c) injecting said alloy in semi-solid form into said mold;
- (d) cooling said mold to solidify said semi-solid base aluminum alloy to provide said cast member having a globular microstructure contained in a lower melting eutectic matrix;
- (e) aging said member at a temperature in the range of 200° to 400° F. for a period of 1 to 24 hours.
A method of forming an aluminum base alloy formed member having a globular microstructure contained in a lower melting eutectic matrix, the method comprising the steps of:
- (a) providing a body of a semi-solid aluminum base alloy comprising 3.5 to 49 wt. % Si, 3.6 to 5 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance aluminum incidental elements and impurities;
- (b) providing a mold for said member;
- (c) injecting said alloy in semi-solid form into said mold;
- (d) solidifying said semi-solid base aluminum alloy in said mold to provide said formed member having a globular microstructure contained in a lower melting eutectic matrix;
- (e) solution heat treating said member in a temperature range of 800° to 1000° F. for a period of 0.1 to 12 hours to provide a solution heat treated member;
- (f) quenching said solution heat treated member to provide a quenched member;
- and
- (g) aging said quenched member to provide an aged member having a tensile strength in the range of 45 to 65 ksi and a yield strength in the range of 40 to 55 ksi.
A method of forming an aluminum base alloy formed member having a globular microstructure contained in a lower melting eutectic matrix, the method comprising the steps of:
- (a) providing a body of a semi-solid aluminum base alloy comprising 3.5 to 4.9 wt. % Si, 3.7 to 4.8 wt. % Cu, 0.3 to 1 wt. % Mg, max. 0.25 wt. % Fe, max. 0.1 wt. % Mn, max. 0.25 wt. % Zn, and max. 0.25 wt. % Ti, the balance aluminum, incidental elements and impurities;
- (b) providing a mold for said member;
- (c) injecting said alloy in semi-solid form into said mold;
- (d) solidifying said semi-solid base aluminum alloy in said mold to provide said formed member having a globular microstructure contained in a lower melting eutectic matrix;
- and
- (e) aging said member to provide an aged member having a tensile strength in the range of 45 to 65 ksi and a yield strength in the range of 40 to 55 ksi in the T6 condition.
Dependencies are inferred from the claim text.