Bonded thermite composition

Abstract

Thermite mixtures shaped or cast into a desired solid form and having sufficient structural integrity to withstand rough handling and challenging operating conditions, and methods of making such solid forms, are provided. When reacted, the thermite mixtures advantageously produce little or no offgas. The solid thermite forms may further include other materials that confer advantageous physical or chemical properties before, during, or after reaction of the thermite mixture.

1 . A method for making a bonded thermite composition, comprising:
 heat-treating a mixture of a thermite and a boron oxide precursor to form molten boron oxide, wherein the thermite comprises a fuel component and an oxidizer component; and   cooling the mixture to solidify the molten boron oxide and form a glassy binding phase comprising boron oxide.   
     
     
         2 . The method of  claim 1 , wherein the boron oxide comprises diboron trioxide and wherein the boron oxide precursor is selected from the group consisting of diboron trioxide, boric acid, and combinations thereof. 
     
     
         3 . The method of  claim 1 , wherein, during the heat-treating step, the liquid boron trioxide facilitates liquid-phase sintering of at least one of the fuel component and the oxidizer component. 
     
     
         4 . The method of  claim 1 , further comprising adding a solvent to the mixture. 
     
     
         5 . The method of  claim 4 , wherein the solvent is water. 
     
     
         6 . The method of  claim 4 , further comprising casting the mixture into a mold. 
     
     
         7 . The method of  claim 1 , wherein the thermite mixture comprises from about 80% to about 120% of the stoichiometric amount of the fuel component required for complete reaction with the oxidizer component. 
     
     
         8 . The method of  claim 1 , wherein the bonded thermite composition comprises from about 50 wt % to about 99 wt % of the thermite mixture and from about 1 wt % to about 50 wt % of the glassy binding phase. 
     
     
         9 . The method of  claim 1 , wherein the fuel component is selected from the group consisting of metallic aluminum, magnesium, silicon, manganese, an alloy of magnesium and aluminum, and combinations thereof. 
     
     
         10 . The method of  claim 1 , wherein the oxidizer component is selected from the group consisting of vanadium(V) oxide, iron(III) oxide, iron(II,III) oxide, copper(II) oxide, copper(I) oxide, tin(IV) oxide, titanium dioxide, diboron trioxide, manganese dioxide, manganese(III) oxide, chromium(III) oxide, cobalt(II) oxide, silicon dioxide, nickel(II) oxide, silver oxide, molybdenum trioxide, and combinations thereof. 
     
     
         11 . The method of  claim 1 , wherein the mixture further comprises at least one fiber of an inorganic material. 
     
     
         12 . The method of  claim 11 , wherein the inorganic material is selected from the group consisting of aluminum, silicon dioxide, and combinations thereof. 
     
     
         13 . The method of  claim 1 , wherein the bonded thermite composition is substantially free of water and organic materials. 
     
     
         14 . The method of  claim 1 , wherein the heat-treating step is carried out under an oxidizing or inert atmosphere.