Casting thermal transforming and semi-solid forming aluminum alloys

A process for casting, thermally transforming and semi-solid forming an aluminum base alloy into an article, the process comprising the steps of:

• (a) providing a molten body of said aluminum base alloy comprising 2 to 5 wt. % Si, 0.3 to 1.7 wt. % Mg, and 0.3 to 1.2 wt. % Cu, 0.05 to 0.4 wt. % Fe and at least one of the group consisting of 0.01 to 1 wt. % Mn, 0.01 to 0.35 wt. % Cr, max. 0.2 wt. % Ti, max. 0.3 wt. % V, balance aluminum and incidental elements and impurities;
• (b) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy to provide a solidified body having a dendritic microstructure having a grain size in the range of 20 to 250 .mu.m;
• (c) thereafter, applying heat by inductively heating said solidified body to bring said solidified body to a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminum base alloy, said rate of heating to said superheated temperature being at a rate in the range of 200.degree. to 1000C./min;
• (d) effecting thermal transformation of said body having said dendritic structure to a body having a globular structure contained in a lower melting eutectic when said entire body is heated to said superheated temperature;
• and
• (e) forming said body having said globular structure in a semi-solid condition into said article.

A process for casting, thermally transforming and semi-solid forming an aluminum base alloy into an article, the process comprising the steps of:

• (a) providing a molten body of said aluminum base alloy comprising 2.1 to 4.4 wt. % Si, 0.35 to 1.45 wt. % Mg, 0.35 to 1.2 wt. % Cu, 0.05 to 0.4 wt. % Fe and at least one of the group consisting of 0.01 to 1 wt. % Mn, 0.01 to 0.35 wt. % Cr, max. 0.2 wt. % Ti, max. 0.3 wt. % V, the remainder comprising aluminum, incidental elements and impurities;
• (b) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy in a range of 50.degree. to 100.degree. C./sec to provide a solidified body having a dendnitic microstructure having a grain size in the range of 20 to 250 .mu.m;
• (c) thereafter, applying heat by induction heating to said solidified body to heat said body at a rate greater than 30.degree. C. per minute to bring said body a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminum base alloy while maintaining said body in a solid shape;
• (d) effecting thermal transformation of said body having said dendritic structure when uniformly heated to said superheated temperature to provide a body having a globular structure;
• and
• (e) forming said body having said globular structure in a semi-solid condition into said article.

A process for casting, thermally transforming and semi-solid forming an aluminum base alloy into an article, the process comprising the steps of:

• (a) providing a molten body of said aluminum base alloy comprised of 2 to 5 wt. % Si, 0.3 to 1.7 wt. % Mg, 0.3 to 1.2 wt. % Cu, 0.05 to 0.4 wt. % Fe, and at least one of the group consisting of 0.01 to 1 wt. % Mn, 0.01 to 0.35 wt. % Cr, max. 0.2 wt. % Ti, max. 0.3 wt. % V;
• (b) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy in a range of 5.degree. to 100.degree. C./sec. to provide a solidified body having a dendritic microstructure;
• (c) thereafter, applying heat by induction heating to said solidified body to heat said body at a rate greater than 30.degree. C. per minute to bring said body a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminumn base alloy while maintaining said body in a solid shape;
• (d) effecting thermal transformation of said body having said dendritic structure when uniformly heated to said superheated temperature to provide a body having a non-dendritic structure;
• (e) forming said body having said non-dendritic structure in a semi-solid condition into said article;
• and
• (f) artificially aging said article.

In a method of semi-solid forming shaped aluminum alloy articles wherein the aluminum alloy is provided as a billet, the improvement wherein said billet is provided in an aluminum base alloy comprising 2 to 5 wt. % Si, 0.3 to 1.7 wt. % Mg, 0.3 to 1.2 wt. % Cu, 0.05 to 0.4 wt. % Fe, and at least one of the group consisting of 0.01 to 1 wt. % Mn, 0.01 to 0.35 wt. % Cr, max. 0.2 wt. % Ti, max. 0.3 wt. % V, the balance aluminum, incidental elements and impurities, said shaped article further being provided in the condition resulting from:

• (a) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy to provide a solidified body having a dendritic grain microstructure having a grain size in the range of 20 to 250 .mu.m;
• (b) thereafter, applying heat by induction heating to said solidified body to heat said body at a rate greater than 30.degree. C. per minute to bring said body to a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminum base alloy;
• (c) effecting thermal transformation of said dendritic structure to a non-dendritic structure when uniformly heated to said superheated temperature to provide a body having a non-dendritic structure;
• and
• (d) forming said body having said non-dendritic structure in a semi-solid condition into said article.

In a method of semi-solid forming shaped aluminum alloy articles wherein the aluminumn alloy is provided as a billet, the improvement wherein said billet is provided in an aluminum base alloy comprising 2 to 5 wt. % Si, 0.3 to 1.7 wt. % Mg, 0.3 to 1.2 wt. % Cu, 0.05 to 0.4 wt. % Fe, and at least one of the group consisting of 0.01 to 1 wt. % Mn, 0.01 to 0.35 wt. % Cr, max. 0.2 wt. % Ti, max. 0.3 wt. % V, the balance aluminum, incidental elements and impurities, said shaped article further being provided in the condition resulting from:

• (a) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy in a range of 5.degree. to 100.degree. C./sec to provide a solidified body having a dendritic microstructure having a grain size in the range of 20 to 200 .mu.m;
• (b) thereafter, inductively heating said solidified body to a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminum base alloy, said rate of heating to said superheated temperature being at a rate in the range of 200.degree. to 1000.degree. C./min;
• (c) maintaining said body at said superheated temperature for a period in the range of 1 second to 5 minutes and effecting thermal transformation of said dendritic microstructure to a body having a globular structure;
• and
• (d) forming said body having said globular structure in a semi-solid condition into said article.

In a method of semi-solid forming shaped aluminum alloy articles wherein the aluminum alloy is provided as a billet, the improvement wherein said billet is provided in an aluminum base alloy comprising 2.1 to 4.4 wt. % Si, 0.35 to 1.45 wt. % Mg, 0.35 to 1.2 wt. % Cu, 0.05 to 0.4 wt. % Fe and at least one of the group consisting of 0.01 to 1 wt. % Mn, 0.01 to 0.35 wt. % Cr, max. 0.2 wt. % Ti, max. 0.3 wt. % V, the remainder comprising aluminum, incidental elements and impurities, said shaped article further being provided in the condition resulting from:

• (a) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy in a range of 5.degree. to 100.degree. C./sec to provide a solidified body having a dendritic microstructure having a grain size in the range of 20 to 250 .mu.m;
• (b) thereafter, applying heat by induction heating to said solidified body to heat said body at a rate greater than 30.degree. C. per minute to bring said body to a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminum base alloy;
• (c) effecting thermal transformation of said dendritic structure to a body having a non-dentritic structure when said body is uniformly heated to said superheated temperature;
• and
• (d) forming said body having said non-dendritic structure in a semi-solid condition into said article.

A process for casting, thermally transforming and semi-solid forming an aluminum base alloy into an article, the process comprising the steps of:

• (a) providing a molten body of said aluminum base alloy comprised of 11 to 30 wt. % Si, 0.45 to 1.3 wt. % Mg, 0.4 to 5 wt. % Cu, max. 1.5 wt. % Fe, max. 0.6 wt. % Mn, max. 2.5 wt. % Ni, max. 0.3 wt. % Ti, max. 0.3 wt. % Sn, the balance comprising aluminum, incidental elements and impurities;
• (b) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy in a range of 5.degree. to 100.degree. C./sec. to provide a solidified body having a dendritic microstructure;
• (c) thereafter, applying heat by induction heating to said solidified body to heat said body at a rate greater than 30.degree. C. per minute to bring said body to a temperature between solidus and liquidus temperature of said aluminum base alloy while maintaining said body in a solid shape;
• (d) effecting thermal transformation of said body having said dendritic structure to provide a body having a non-dendritic structure when said body is heated to said temperature between solidus and liquidus temperature;
• and
• (e) forming said body having said non-dendritic structure in a semi-solid condition into said article.

A process for casting, thermally transforming and semi-solid forming an aluminum base alloy into an article, the process comprising the steps of:

• (a) providing a molten body of said aluminum base alloy comprised of 11 to 30 wt. % Si, 0.45 to 1.3 wt. % Mg, 0.4 to 5 wt. % Cu, max. 1.5 wt. % Fe, max. 0.6 wt. % Mn, max. 2.5 wt. % Ni, max. 0.3 wt. % Ti, max. 0.3 wt. % Sn, the balance comprising aluminum, incidental elements and impurities;
• (b) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy to provide a solidified body having a dendritic microstructure having a grain size in the range of 20 to 250 .mu.m;
• (c) thereafter, applying heat by inductively heating said solidified body to bring said solidified body to a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminum base alloy, said applying heat to said superheated temperature being at a rate in the range of 200.degree. to 1000.degree. C./min;
• (d) effecting thermal transformation of said body having said dendritic structure to a body having a globular structure contained in a lower melting eutectic when said entire body is heated to said superheated temperature, and
• (e) forming, said body having said globular structure in a semi-solid condition into said article.

A process for casting, thermally transforming and semi-solid solid forming an aluminum base alloy into an article, the process comprising the steps of:

• (a) providing a molten body of said aluminum base alloy comprising 15 to 25 wt. % Si, 0.4 to 0.7 wt. % Mg, 4 to 5 wt. % Cu, max. 1.5 wt. % Fe, max. 0.6 wt. % Mn, max. 2.5 wt. % Ni, max. 0.3 wt. % Ti, max. 0.3 wt. % Sn, the balance comprising aluminum, incidental elements and impurities;
• (b) casting said molten body of aluminum base alloy to provide a solidified body, said molten aluminum base alloy being solidified at a rate between liquidus and solidus temperatures of the aluminum base alloy in a range of 5.degree. to 100.degree. C./sec to provide a solidified body having a dendritic microstructure having a grain size in the range of 20 to 250 .mu.m;
• (c) thereafter, applying heat by induction heating to said solidified body to heat said body at a rate greater than 30.degree. C. per minute to bring said body a superheated temperature of 3.degree. to 50.degree. C. above said solidus temperature of said aluminumn base alloy while maintaining said body in a solid shape;
• (d) effecting thermal transformation of said body having said dendritic structure to a body having a globular structure when uniformly heated to said superheated temperature;
• and
• (e) forming said body having said globular structure in a semi-solid condition into said article.