Metal matrix composites including inorganic particles and discontinuous fibers and methods of making same

Abstract

A metal matrix composite is provided, including a metal, inorganic particles, and discontinuous fibers. The inorganic particles and the discontinuous fibers are dispersed in the metal. The metal includes aluminum, magnesium, or alloys thereof. The inorganic particles have an envelope density that is at least 30% less than a density of the metal. The metal matrix composite has a lower envelope density than the matrix metal while retaining a substantial amount of the mechanical properties of the metal.

1 . A metal matrix composite, comprising:
 a. a metal, the metal comprising aluminum, magnesium, or alloys thereof;   b. a plurality of inorganic particles, the inorganic particles having an envelope density that is at least 30% less than a density of the metal; and   c. a plurality of discontinuous fibers,   wherein the inorganic particles and the discontinuous fibers are dispersed in the metal.   
     
     
         2 . The metal matrix composite of  claim 1 , wherein the metal matrix composite has an envelope density that is at least 8% less than the density of the metal and can withstand a strain of 1% prior to fracture. 
     
     
         3 . The metal matrix composite of  claim 2 , wherein the metal matrix composite can withstand a strain of 2% prior to fracture. 
     
     
         4 . The metal matrix composite of  claim 1 , wherein the metal matrix composite has a yield strength of 50 megapascals or greater. 
     
     
         5 . The metal matrix composite of  claim 1 , wherein the plurality of inorganic particles comprises porous particles comprising porous metal oxide particles, porous metal hydroxide particles, porous metal carbonates, porous carbon particles, porous silica particles, porous dehydrated aluminosilicate particles, porous dehydrated metal hydrate particles, zeolite particles, porous glass particles, expanded perlite particles, expanded vermiculite particles, porous sodium silicate particles, engineered porous ceramic particles, agglomerates of nonporous primary particles, or combinations thereof. 
     
     
         6 . The metal matrix composite of  claim 1 , wherein the plurality of inorganic particles comprises ceramic bubbles or glass bubbles. 
     
     
         7 . The metal matrix composite of  claim 6 , wherein the plurality of inorganic particles comprises alumina, aluminosilicate, silica, or combinations thereof. 
     
     
         8 . The metal matrix composite of  claim 1 , wherein the plurality of inorganic particles comprises an average particle size ranging between 1 μm and 1 mm, inclusive. 
     
     
         9 . The metal matrix composite of  claim 1 , wherein the plurality of discontinuous fibers comprises glass, alumina, aluminosilicate, carbon, basalt, or a combination thereof. 
     
     
         10 . The metal matrix composite of  claim 1 , wherein the metal comprises a porous matrix structure. 
     
     
         11 . The metal matrix composite of  claim 1 , wherein the metal comprises aluminum or alloys thereof and wherein the metal matrix composite has an envelope density between 1.80 and 2.50 grams per cubic centimeter, inclusive. 
     
     
         12 . The metal matrix composite of  claim 1 , wherein the metal comprises magnesium or alloys thereof and wherein the metal matrix composite has an envelope density between 1.35 and 1.60 grams per cubic centimeter, inclusive. 
     
     
         13 . The metal matrix composite of  claim 1 , wherein the metal matrix composite exhibits a yield strength before failure in a tensile test. 
     
     
         14 . The metal matrix composite of  claim 1 , wherein the metal is present in an amount of between 50 weight percent and 95 weight percent, inclusive, of the metal matrix composite. 
     
     
         15 . The metal matrix composite of  claim 1 , wherein the metal matrix composite consists essentially of the metal; the plurality of inorganic particles; and the plurality of discontinuous fibers.