Unworked continuously cast heat-treatable aluminum alloy plates

Abstract

The present disclosure relates to methods of producing heat-treatable as-cast plate, and products based on the same. Generally, the new methods comprise continuously delivering a molten aluminum alloy having at least one of zinc (Zn), magnesium (Mg), silicon (Si), and copper (Cu) to a molten belt caster, continuously solidifying the molten aluminum alloy into an aluminum alloy plate via the horizontal belt caster, then continuously discharging the aluminum alloy plate at an exit of the horizontal belt caster, and then quenching the discharged aluminum alloy plate via a quenching apparatus located proximal the exit of the horizontal belt caster.

What is claimed is: 
     
         1 . A method comprising:
 (a) continuously delivering a molten aluminum alloy to a horizontal belt caster;
 (i) wherein the molten aluminum alloy comprises a sufficient amount of at least one of zinc (Zn), magnesium (Mg), silicon (Si), and copper (Cu) to promote formation of strengthening precipitates; 
   (b) continuously solidifying the molten aluminum alloy into an aluminum alloy plate via the horizontal belt caster;   (c) continuously discharging the aluminum alloy plate from an exit of the horizontal belt caster at a rate of from 1 inch to 20 inches per minute;
 (i) wherein the discharged aluminum alloy plate has a gauge of from 0.25 inch to 5.0 inches; 
   (d) quenching the discharged aluminum alloy plate via a quenching apparatus located proximal the exit of the horizontal belt caster, thereby producing an as-cast heat-treatable aluminum alloy plate;
 (i) wherein the quenching comprises contacting outer surfaces of the discharged aluminum alloy plate with a quenching media. 
   
     
     
         2 . The method of  claim 1 , further comprising:
 artificially aging the as-cast heat-treatable aluminum alloy plate, thereby developing strengthening precipitates within the as-cast heat-treatable aluminum alloy plate.   
     
     
         3 . The method of  claim 2 , wherein the strengthening precipitates are coherent phases comprising silicon, copper, magnesium and/or zinc. 
     
     
         4 . The method of  claim 3 , wherein the as-cast heat-treatable aluminum alloy plate comprises a sufficient amount of the strengthening precipitates to realize a peak strength (T6) that is at least 5 ksi higher than the naturally aged strength (T3). 
     
     
         5 . The method of  claim 2 , wherein the as-cast heat-treatable aluminum alloy plate comprises an as-cast grain structure, the method comprising
 maintaining the as-cast grain structure of the heat-treatable aluminum alloy plate;   wherein, after the artificially aging step, the heat-treatable aluminum alloy plate comprises the as-cast grain structure with the strengthening precipitates.   
     
     
         6 . The method of  claim 5 , comprising:
 providing the as-cast heat-treatable aluminum alloy plate to a customer, wherein the as-cast heat-treatable aluminum alloy plate comprises the as-cast grain structure and the strengthening precipitates.   
     
     
         7 . The method of  claim 5 , wherein the maintaining step comprises forgoing hot or cold working of the as-cast heat-treatable aluminum alloy plate after the continuously casting step. 
     
     
         8 . The method of  claim 1 , comprising:
 melting an aluminum alloy scrap feedstock, thereby producing the molten aluminum alloy;   wherein the aluminum alloy scrap feedstock comprises a combination of scrap of at least two different aluminum alloys.   
     
     
         9 . The method of  claim 8 , wherein the at least two different aluminum alloys are at least two different classes of aluminum alloys. 
     
     
         10 . The method of  claim 9 , wherein the at least two different classes of aluminum alloys are selected from the following aluminum alloy series: 1xxx, 2xxx, 3xxx, 4xxx, 5xxx, 6xxx, 7xxx, and 8xxx aluminum alloys. 
     
     
         11 . The method of  claim 9 , wherein the at least two different classes of aluminum alloys are selected from the following aluminum alloy series: 3xxx, 4xxx, 5xxx, 6xxx, and 7xxx aluminum alloys. 
     
     
         12 . The method of  claim 9 , wherein the at least two different aluminum alloys are selected from the group consisting of 3xxx, 4xxx, 5xxx, and 6xxx aluminum alloy scrap. 
     
     
         13 . The method of  claim 8 , wherein the at least two different aluminum alloys are from the same class of aluminum alloys. 
     
     
         14 . The method of  claim 13 , wherein at least two different aluminum alloys are both 6xxx aluminum alloys. 
     
     
         15 . The method of  claim 13 , wherein the two different aluminum alloys are both 7xxx aluminum alloys. 
     
     
         16 . The method of  claim 13 , wherein the at least two different aluminum alloys are both 2xxx aluminum alloys. 
     
     
         17 . The method of  claim 1 , wherein the discharged aluminum alloy plate is one of a 2xxx, 6xxx, 7xxx, and 8xxx(HT) aluminum alloy plate. 
     
     
         18 . An as-cast aluminum alloy plate having a thickness of from 0.25 inch to 5.0 inches;
 wherein the as-cast aluminum alloy plate comprises at least 0.5 wt. % of at least one at least one of zinc (Zn), magnesium (Mg), silicon (Si), and copper (Cu);   wherein the as-cast aluminum alloy plate has a dendritic microstructure;   wherein the as-cast aluminum alloy plate has a secondary dendritic arm spacing of from 30 to 150 microns in all of the longitudinal (L), the long-transverse (LT) and the short-transverse (ST) directions of the as-cast aluminum alloy plate;   wherein the as-cast aluminum alloy plate has equiaxed grains and is free of elongated grains.