Additives for improving the castability of aluminum-boron carbide composite material

Abstract

The present disclosure provides additives capable of undergoing a peritectic reaction with boron in aluminum-boron carbide composite materials. The additive may be selected from the group consisting of vanadium, zirconium, niobium, strontium, chromium, molybdenum, hafnium, scandium, tantalum, tungsten and combination thereof, is used to maintain the fluidity of the molten composite material, prior to casting, to facilitate castability.

What is claimed is: 
     
         1 . A method of preparing a cast composite material, said method comprising:
 (a) combining (i) a molten aluminum alloy comprising up to 1.8 w/w % of silicon based on a total weight of the aluminum alloy and an additive capable of undergoing a peritectic reaction with boron with (ii) between 4 and 40 v/v % of a source of boron carbide particles so as to provide a molten composite material comprising products of the peritectic reaction between the additive and boron and dispersed boron carbide particles, wherein:
 the additive is selected from the group consisting of chromium, molybdenum, vanadium, niobium, zirconium, strontium, scandium, and any combination thereof; and 
 a sample of the composite material has a fluidity, after having been heated, prior to casting, to a temperature of about 700° C. for about 120 minutes, corresponding to a cast length of at least 100 mm when measured using a mold having a groove for containing the sample, the groove having a width of about 33 mm, a height of between about 6.5 mm and about 4.0 mm and being downwardly inclined, from an horizontal axis, of about 10°; and 
   (b) casting the molten composite so as to form the cast composite material.   
     
     
         2 . The method of  claim 1 , wherein the cast length is at least 190 mm. 
     
     
         3 . The method of  claim 1 , further comprising, prior to step (b), holding the molten composite material during a holding time and casting the molten composite during a casting time, wherein the combination of the holding time and the casting time is at least 120 minutes. 
     
     
         4 . The method of  claim 1 , further comprising, prior to step (a), providing the molten aluminum alloy by combining a molten aluminum or a molten aluminum alloy with the additive. 
     
     
         5 . The method of  claim 1 , wherein the additive is selected from the group consisting of zirconium, strontium, scandium and any combination thereof. 
     
     
         6 . The method of  claim 1 , wherein the additive is scandium. 
     
     
         7 . The method of  claim 1 , wherein the additive is strontium. 
     
     
         8 . The method of  claim 1 , wherein the additive is zirconium. 
     
     
         9 . The method of  claim 1 , wherein the concentration (v/v) of the dispersed boron carbide particles is between 4% and 40% with respect to the total volume of the cast composite material. 
     
     
         10 . The method of  claim 9 , wherein the concentration (w/w) of the additive is between 0.47% and 8.00% with respect to the total weight of the cast composite material. 
     
     
         11 . The method of  claim 10 , further comprising titanium at a concentration (w/w) between 0.50% and 4.00% with respect to the total weight of the cast composite material. 
     
     
         12 . The method of  claim 1 , wherein the concentration (v/v) of the dispersed boron carbide particles is between 4.5% and 18.9% with respect to the total volume of the cast composite material. 
     
     
         13 . The method of  claim 12 , wherein the concentration (w/w) of the additive is between 0.38% and 4.00% with respect to the total weight of the cast composite material. 
     
     
         14 . The method of  claim 13 , wherein the composite material further comprises titanium at a concentration (w/w) between 0.40% and 2.00% with respect to the total weight of the cast composite material. 
     
     
         15 . The method of  claim 1 , wherein the concentration (v/v) of the dispersed boron carbide particles is between 19.0% and 28.0% with respect to the total volume of the cast composite material. 
     
     
         16 . The method of  claim 15 , wherein the concentration (w/w) of the additive is between 1.68% and 6.00% with respect to the total weight of the cast composite material. 
     
     
         17 . The method of  claim 16 , wherein the composite material further comprises titanium at a concentration (w/w) between 1.80% and 3.00% with respect to the total weight of the cast composite material. 
     
     
         18 . The method of  claim 1 , wherein the concentration (v/v) of the dispersed boron carbide particles is between 25.0% and 28.0% with respect to the total volume of the cast composite material. 
     
     
         19 . The method of  claim 1 , wherein the concentration (v/v) of the dispersed boron carbide particles is between 28.0% and 33.0% with respect to the total volume of the cast composite material. 
     
     
         20 . The method of  claim 18 , wherein the concentration (w/w) of the additive is between 0.94% and 4.00% with respect to the total weight of the cast composite material. 
     
     
         21 . The method of  claim 20 , wherein the composite material further comprises titanium at a concentration (w/w) between 1.00% and 2.00% with respect to the total weight of the cast composite material. 
     
     
         22 . A method of improving the casting and/or shaping properties of a molten composite material comprising (i) an aluminum alloy comprising up to 1.8 w/w % of silicon based on a total weight of the aluminum alloy, (ii) products of a peritectic reaction between an additive and boron, and (iii) dispersed boron carbide particles, said method comprising combining (a) a molten aluminum alloy comprising the additive capable of undergoing the peritectic reaction with boron with (b) between 4 and 40 v/v % of a source of boron carbide particles so as to provide a molten composite material, wherein:
 the additive is selected from the group consisting of chromium, molybdenum, vanadium, niobium, zirconium, strontium, scandium, and any combination thereof; and   a sample of the composite material has a fluidity, after having been heated, prior to casting, to a temperature of about 700° C. for about 120 minutes, corresponding to a cast length of at least 100 mm when measured using a mold having a groove for containing the sample, the groove having a width of about 33 mm, a height of between about 6.5 mm and about 4.0 mm and being downwardly inclined, from an horizontal axis, of about 10°.   
     
     
         23 . The method of  claim 22 , wherein the cast length is at least 190 mm. 
     
     
         24 . A method of facilitating shaping of a molten composite material of a molten composite material comprising (i) an aluminum alloy comprising up to 1.8 w/w % of silicon based on a total weight of the aluminum alloy, (ii) products of a peritectic reaction between an additive and boron, and (iii) dispersed boron carbide particles, said method comprising combining (a) a molten aluminum alloy comprising the additive capable of undergoing the peritectic reaction with boron with (b) between 4 and 40 v/v % of a source of boron carbide particles so as to provide a molten composite material, wherein:
 the additive is selected from the group consisting of chromium, molybdenum, vanadium, niobium, zirconium, strontium, scandium, and any combination thereof; and   a sample of the composite material has a fluidity, after having been heated, prior to casting, to a temperature of about 700° C. for about 120 minutes, corresponding to a cast length of at least 100 mm when measured using a mold having a groove for containing the sample, the groove having a width of about 33 mm, a height of between about 6.5 mm and about 4.0 mm and being downwardly inclined, from an horizontal axis, of about 10°.   
     
     
         25 . The method of  claim 24 , wherein the cast length is at least 190 mm.