Metal matrix composites of aluminum, magnesium and titanium using calcium hexaboride

Abstract

A metal matrix composite was fabricated by adding particles of calcium hexaboride to a metal of aluminum, magnesium or titanium and their alloys. The resulting metal matrix composite is light weight has improved strength, increased elastic modulus and reduced thermal coefficient of expansion, thus making the metal matrix composite more useful in industry.

I claim:  
     
         1 . A metal matrix composite comprising a metal selected from the group consisting of aluminum, magnesium, titanium and mixtures thereof, and particles of calcium hexaboride, said particles of calcium hexaboride being present in a range of about 0.1 to about 80 wt. % in the metal.  
     
     
         2 . A metal matrix composite in accordance with  claim 1  wherein said calcium hexaboride has an average particle size of about 0.1 to about 200 microns.  
     
     
         3 . A metal matrix composite in accordance with  claim 1  wherein said metal is aluminum.  
     
     
         4 . A metal matrix composite comprising a metal selected from the group consisting of aluminum, magnesium, titanium and mixtures thereof, and particles of calcium hexaboride and particles of silicon hexaboride, said particles of calcium hexaboride and said particles of silicon hexaboride being present in a range of about 0.1 to about 80 wt. % in the metal.  
     
     
         5 . A metal matrix composite in accordance with  claim 4  wherein said particles of calcium hexaboride and said particles of silicon hexaboride have an average particle size of about 0.1 to about 200 microns.  
     
     
         6 . A metal matrix composite in accordance with  claim 4  wherein said metal is aluminum.  
     
     
         7 . An article of manufacture comprising a metal matrix composite, said metal matrix composite comprises a metal selected from the group consisting of aluminum, magnesium, titanium and mixtures thereof, and particles of calcium hexaboride, said particles of calcium hexaboride are present in a range of about 0.1 to about 80 wt. % in the metal.  
     
     
         8 . An article of manufacture in accordance with  claim 7  wherein said calcium hexaboride has an average particle size of about 0.1 to about 200 microns.  
     
     
         9 . An article of manufacture in accordance with  claim 7  wherein said metal is aluminum.  
     
     
         10 . An article of manufacture in accordance with  claim 7  wherein said article of manufacture is a horseshoe.  
     
     
         11 . An article of manufacture in accordance with  claim 10  wherein said horseshoe was made from an aluminum matrix composite, said aluminum matrix composite containing from about 5 to about 10 wt % calcium hexaboride particles having an average particle size of about 75 microns and the remainder being A356 aluminum metal.  
     
     
         12 . An article of manufacture in accordance with  claim 7  wherein said article of manufacture is a memory disk substrate.  
     
     
         13 . An article of manufacture in accordance with  claim 12  wherein said memory disk substrate was made from an aluminum matrix composite, said aluminum matrix composite containing from about 40 wt % calcium hexaboride particles having an average particle size of about 10 microns and the remainder being aluminum metal.  
     
     
         14 . An article of manufacture in accordance with  claim 7  wherein said article of manufacture is an actuator arm for a hard drive.  
     
     
         15 . An article of manufacture in accordance with  claim 14  wherein said actuator arm for a hard drive was made from an aluminum matrix composite, said aluminum matrix composite containing from about 30 wt % calcium hexaboride particles having an average particle size of about 50 microns and the remainder being A356 aluminum metal.