Manufacture of alloys containing dispersed fine particulate material

Abstract

A method of preparing a metal alloy comprising a dispersion of particles of a first metallic material consisting of one or more refractory hard metals in a matrix of a second metallic material includes establishing a molten body of the second metallic material and introducing solid particles of the first metallic material into the molten body. Alternatively solid particles of a metalloid which reacts with the second metallic material to form particles of the first metallic material may be introduced into the molten body. The first metallic material has a higher melting point than the second metallic material and is substantially insoluble therein. The molten body is then stirred at a rate sufficient to effect shearing of the surfaces of the particles such that the surfaces are wetted by the molten body, and the molten body containing the resultant dispersion is cast in any desired manner.

1 . A method of preparing a metal alloy comprising a dispersion of particles of a first metallic material consisting of one or more refractory hard metals in a matrix of a second metallic material comprising the steps of: 
 (i) establishing a molten body of said second metallic material    (ii) introducing solid particles of said first metallic material into said molten body, whilst    (iii) stirring said molten body at a rate sufficient to effect shearing of the surfaces of said particles such that said surfaces are wetted by said molten body    (iv) casting said molten body containing the resultant dispersion by any desired means wherein said first metallic material has a higher melting point than said second metallic material and is substantially insoluble therein.    
     
     
         2 . A method of preparing a metal alloy comprising a dispersion of particles of a first metallic material consisting of one or more refractory hard metals in a matrix of a second metallic material comprising the steps of: 
 (i) establishing a molten body of said second metallic material    (ii) introducing into said body solid particles of a metalloid which reacts with said second metallic material to form particles of said first metallic material    (iii) stirring said molten body at a rate sufficient to effect shearing of the surfaces of the particles of said metalloid such that said surfaces are wetted by said molten body    (iv) casting said molten body containing the resultant dispersion by any desired means wherein said first metallic material has a higher melting point than said second metallic material and is substantially insoluble therein.    
     
     
         3 . A method according to  claim 1  wherein said molten body is established in an upright cylindrical vessel heated by any appropriate means and dispersion and wetting are achieved by one or more power driven impellers.  
     
     
         4 . A method according to  claim 2  wherein said molten body is established in an upright cylindrical vessel heated by any appropriate means and dispersion and wetting are achieved by one or more power driven impellers.  
     
     
         5 . A method according to  claim 1  wherein said second metallic material is unalloyed aluminum.  
     
     
         6 . A method according to  claim 2  wherein said second metallic material is unalloyed aluminum.  
     
     
         7 . A method according to  claim 1  wherein said second metallic material is unalloyed aluminum and said first metallic material is titanium diboride.  
     
     
         8 . A method according to  claim 1  wherein said second metallic material is unalloyed aluminum and said first metallic material is an aluminum boride,  
     
     
         9 . A method according to  claim 2  wherein said second metallic material is unalloyed aluminum and said metalloid is elemental boron.  
     
     
         10 . A method according to  claim 1  wherein said molten body is maintained under vacuum.  
     
     
         11 . A method according to  claim 2  wherein said molten body is maintained under vacuum.  
     
     
         12 . A method according to  claim 1  wherein said molten body is maintained under an atmosphere of argon gas.  
     
     
         13 . A method according to  claim 2  wherein said molten body is maintained under an atmosphere of argon gas.