Continuous production of large diameter bars for semi-solid forming

Abstract

A process and equipment is disclosed for the production and use of precursor material in the continuous production of large diameter bars for semi-solid forming. The invention discloses the production and use of precursor material for the semi solid formation of light non-ferrous metals, non-ferrous copper-based alloys and metal matrix composites (MMC) based on the above metals. The inventive process and equipment allows extrusion of material bars with a negative extrusion ratio for use in semi-solid forming.

What is claimed is:  
     
         1 . A process for preparing precursor material for semi-solid forming, comprising: 
 adapting a precursor material for manufacture into a shaped article by semi-solid forming;    casting a rod of said precursor material;    purifying the precursor material rod to remove impurities; and    hot rolling the rod into a substantially circular cross section.    
     
     
         2 . The process of  claim 1  wherein said adapting step comprises: 
 alloying a precursor material to a composition suitable for semi-solid forming.  
 
     
     
         3 . The process of  claim 1 , further comprising: 
 coiling the rod into spools or reels.    
     
     
         4 . The process of  claim 1  wherein said purifying step comprises the step of scalping said precursor material rod.  
     
     
         5 . The process of  claim 1  wherein said purifying step is selected from the group consisting of: chemical cleaning with NaOH/HNO 3 ; dry machining; shot blasting; electrochemical cleaning; ultrasonic cleaning; electromagnetic induced abrasive cleaning; and any combination thereof.  
     
     
         6 . The process of  claim 1 , further comprising the step of: 
 frictionally extruding said precursor material rod to form a precursor material bar.    
     
     
         7 . The process of  claim 6  wherein said frictional extrusion step is performed by a continuous extrusion device.  
     
     
         8 . The process of  claim 1  wherein said precursor material is selected from the group consisting of: light non-ferrous metal, non-ferrous copper-based alloy and metal matrix composite.  
     
     
         9 . The process of  claim 8  wherein said light non-ferrous metal is selected from the group consisting of: aluminum, magnesium, titanium and alloys thereof.  
     
     
         10 . A process for using precursor material in semi-solid forming, comprising: 
 preparing a precursor material rod;    frictionally extruding said precursor material rod to form a precursor material bar; and    heating said precursor material bar at a selected heating rate to a temperature between the solidus and liquidus temperatures of the material and maintaining the temperature for a specific time wherein the precursor material acquires a microstructure which consists of discrete spheroidal particles suspended in a lower melting liquid matrix.    
     
     
         11 . The process of  claim 10  wherein said step of preparing the precursor material rod comprises: 
 adapting a precursor material for manufacture into a shaped article by semi-solid forming;  
 casting a rod of said precursor material;  
 purifying the rod to remove impurities; and  
 hot rolling the rod into a substantially circular cross section.  
 
     
     
         12 . The process of  claim 10  wherein said precursor material rod is frictionally extruded with a negative extrusion ratio.  
     
     
         13 . The process of  claim 10 , further comprising the step of in-line heating said precursor material rod at a temperature below the solidus temperature of the material.  
     
     
         14 . The process of  claim 10  wherein said precursor material is selected from the group consisting of light non-ferrous metal, non-ferrous copper-based alloy and metal matrix composite.  
     
     
         15 . The process of  claim 14  wherein said light non-ferrous metal is selected from the group consisting of: aluminum, magnesium, titanium and alloys thereof.  
     
     
         16 . The process of  claim 10  further comprising the step of: 
 semi-solid forming the heated precursor material bar into a shaped article.  
 
     
     
         17 . A continuous extrusion apparatus employed in the integral process for semi-solid forming, comprising: 
 a frictional extrusion source for frictionally extruding a precursor material rod;    a transfer chamber in communication with the frictional extrusion source for collecting the frictionally extruded precursor material from the frictional extrusion source;    an accumulation chamber, said accumulation chamber being connected to the transfer chamber for accumulating specific amounts of frictionally extruded precursor material; and    an extrusion die held by a die and chamber holding set and connected to the accumulation chamber, wherein a precursor material bar is extruded from the extrusion die.    
     
     
         18 . The apparatus of  claim 17  wherein said accumulation chamber is adapted to frictionally extruded material with a negative extrusion ratio.  
     
     
         19 . The apparatus of  claim 17  wherein said accumulation chamber comprises at least one section wherein said at least one section is of a type selected from the group consisting of: expansion, contraction, landing, and any combination thereof.  
     
     
         20 . The apparatus of  claim 17  wherein said frictional extrusion source comprises a continuous rotary extrusion device.  
     
     
         21 . The apparatus of  claim 17  wherein said precursor material is selected from the group consisting of: light non-ferrous metal, non-ferrous copper-based alloy and metal matrix composite.  
     
     
         22 . The apparatus of  claim 21  wherein said light non-ferrous metal is selected from the group consisting of: aluminum, magnesium, titanium and alloys thereof.  
     
     
         23 . A frictionally extruded material bar produced by a process comprising the steps of: 
 preparing a precursor material rod; and    frictionally extruding a precursor material rod with a negative extrusion ratio.    
     
     
         24 . The frictionally extruded material bar of  claim 22  wherein said preparing step comprises: 
 adapting a precursor material for manufacture into a shaped article by semi-solid forming;  
 casting a rod of said precursor material;  
 purifying the precursor material rod to remove impurities; and  
 hot rolling the rod into a substantially circular cross section.