7xx aluminum casting alloys, and methods for making the same
New 7xx aluminum casting alloys are disclosed. The aluminum casting alloys generally include from 3.0 to 8.0 wt. % Zn, from 1.0 to 3.0 wt. % Mg, where the wt. % Zn exceeds the wt. % Mg, from 0.35 to 1.0 wt. % Cu, where the wt. % Mg exceeds the wt. % Cu, from 0.05 to 0.30 wt. % V, from 0.01 to 1.0 wt. % of at least one secondary element (Mn, Cr, Zr, Ti, B, and combinations thereof), up to 0.50 wt. % Fe, and up to 0.25 wt. % Si, the balance being aluminum and other elements, wherein the aluminum casting alloy include not greater than 0.05 wt. % each of the other elements, and wherein the aluminum casting alloy includes not greater than 0.15 wt. % in total of the other elements.
1. A shape-cast aluminum alloy part consisting of:
(a) from 4.0 to 5.5 wt. % Zn;
(b) from 1.0 to 2.0 wt. % Mg;
(c) from 0.35 to 1.0 wt. % Cu;
wherein the wt. % Mg exceeds the wt. % Cu;
(d) from 0.05 to 0.30 wt. % V;
(e) from 0.01 to 1.0 wt. % of at least one secondary element, wherein the at least one secondary element is selected from the group consisting of Mn, Cr, Zr, Ti, B, and combinations thereof;
wherein, when present, the shape-cast aluminum alloy part includes not greater than 0.50 wt. % Mn as a secondary element;
wherein, when present, the shape-cast aluminum alloy part includes not greater than 0.40 wt. % Cr as a secondary element;
wherein, when present, the shape-cast aluminum alloy part includes not greater than 0.25 wt. % Zr as a secondary element;
wherein, when present, the shape-cast aluminum alloy part includes not greater than 0.25 wt. % Ti as a secondary element;
wherein, when present, the shape-cast aluminum alloy part includes not greater than 0.05 wt. % B as a secondary element;
(f) up to 0.15 wt. % Fe
(g) up to 0.15 wt. % Si; and
(h) the balance being aluminum and other elements, wherein the shape-cast aluminum alloy part includes not greater than 0.03 wt. % each of the other elements, and wherein the shape-cast aluminum alloy part includes not greater than 0.10 wt. % in total of the other elements;
wherein the shape-cast aluminum alloy part is produced by low pressure die casting, gravity permanent mold casting, semi-permanent mold casting, sand mold casting, or spin/centrifugal casting;
wherein the shape-cast aluminum alloy part is a body-in-white or suspension part;
wherein the shape-cast aluminum alloy part realizes a tensile yield strength of not greater than 330 MPa; and
wherein the shape-cast aluminum alloy part passes SCC testing in accordance with ASTM G103-97(2011), wherein the SCC testing is conducted at a net stress of 240 MPa, wherein 5 specimens are tested, and wherein all of the 5 specimens did not fail under the standard ASTMG103-97 (2011) for at least 14 days.
2. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes not greater than 1.8 wt. % Mg.
3. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes at least 1.1 wt. % Mg.
4. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes at least 1.2 wt. % Mg.
5. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes at least 1.3 wt. % Mg.
6. The shape-cast aluminum alloy part of claim 2 , wherein the shape-cast aluminum alloy part includes at least 1.4 wt. % Mg.
7. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes not greater than 0.25 wt. % V.
8. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes not greater than 0.20 wt. % V.
9. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes not greater than 0.18 wt. % V.
10. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes not greater than 0.16 wt. % V.
11. The shape-cast aluminum alloy part of claim 6 , wherein the shape-cast aluminum alloy part includes not greater than 0.14 wt. % V.
12. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes at least 0.06 wt. % V.
13. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes at least 0.07 wt. % V.
14. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes at least 0.08 wt. % V.
15. The shape-cast aluminum alloy part of claim 11 , wherein the shape-cast aluminum alloy part includes at least 0.09 wt. % V.
16. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes not greater than 0.95 wt. % Cu.
17. The shape-cast aluminum alloy part of claim 1 , wherein the shape-cast aluminum alloy part includes not greater than 0.80 wt. % Cu.
18. The shape-cast aluminum alloy part of claim 17 , wherein the shape-cast aluminum alloy part includes at least 0.40 wt. % Cu.
19. The shape-cast aluminum alloy part of claim 17 , wherein the shape-cast aluminum alloy part includes at least 0.50 wt. % Cu.