Metal matrix composites, and methods for making the same

Abstract

Methods for making metal matrix composite inserts and metal matrix composite articles.

1 . A method for making a metal matrix composite insert, the method comprising: 
 providing a three dimensional array of elongated metal matrix composite articles secured together wherein at least three of the elongated metal matrix composite articles each comprise a plurality of substantially continuous fibers selected from the group consisting of boron fibers, boron nitride fibers, carbon fibers, ceramic oxide fibers, graphite fibers, silicon carbide fibers, and combinations thereof in a metal selected from the group consisting of aluminum, magnesium, and alloys thereof, wherein the metal secures the substantially continuous fibers in place, and wherein the metal extends along at least a portion of the length of the substantially continuous fibers; and    consolidating the three dimensional array of elongated metal matrix composite articles secured together under pressure to provide a metal matrix composite insert, wherein the metal matrix composite insert comprises the substantially continuous fibers and metal of the elongated metal matrix composite articles, wherein such metal secures the substantially continuous fibers in place, wherein such metal extends along at least a portion of the length of the substantially continuous fibers, wherein the metal matrix composite insert includes a microstructure comprising plurality of generally polygonal shapes, and wherein for at least some of the generally polygonal shapes, each generally polygonal shape generally shares a common vertex with at least two adjacent generally polygonal shapes.    
   
   
       2 . The method according to  claim 1 , wherein the plurality of generally polygonal shapes comprises generally hexagonal shapes.  
   
   
       3 . The method according to  claim 1 , wherein the three dimensional array of elongated metal matrix composite articles are secured together with at least one of metal wire, graphite thread, or ceramic thread.  
   
   
       4 . The method according to  claim 1 , wherein the three dimensional array of elongated metal matrix composite articles are secured together by at least surrounding the three dimensional array of elongated metal matrix composite articles with at least one of metal foil or graphite foil.  
   
   
       5 . The method according to  claim 4 , wherein the metal matrix composite insert has an outer surface, and wherein the method further comprises providing a metal onto the outer surface.  
   
   
       6 . The method according to  claim 4 , wherein the metal matrix composite insert has an outer surface, and wherein the method further comprises providing at least one of a zinc or tin layer onto the outer surface.  
   
   
       7 . The method according to  claim 4 , wherein the metal matrix composite insert has an outer surface, and wherein the method further comprises providing a metal layer having a positive Gibbs oxidation free energy at a temperature above at least 200° C. onto the outer surface.  
   
   
       8 . The method according to  claim 7 , wherein the metal layer having a positive Gibbs oxidation free energy at a temperature above at least 200° C. has a thickness of at least 8 micrometers.  
   
   
       9 . The method according to  claim 4 , wherein the metal matrix composite insert has an outer surface, and wherein the metal matrix composite insert further comprises, in order (i) at least one of a zinc or tin layer, (ii) a nickel layer, and (iii) a metal layer having a positive Gibbs oxidation free energy at a temperature above at least 200° C onto the outer surface.  
   
   
       10 . The method according to  claim 9 , wherein the metal matrix composite insert has a transverse strength of at least 275 MPa.  
   
   
       11 . The method according to  claim 9 , wherein the plurality of substantially continuous fibers includes the substantially continuous ceramic oxide fibers, and wherein the metal securing the substantially continuous ceramic oxide fibers is selected from the group consisting of aluminum and alloys thereof.  
   
   
       12 . The method according to  claim 2 , wherein the plurality of substantially continuous fibers includes the substantially continuous ceramic oxide fibers, and wherein the metal of the substantially continuous ceramic oxide fibers is selected from the group consisting of aluminum and alloys thereof.  
   
   
       13 . The method according to  claim 12 , wherein the three dimensional array of elongated metal matrix composite articles are secured together with at least one of metal wire, graphite thread, or ceramic thread.  
   
   
       14 . The method according to  claim 12 , wherein the three dimensional array of elongated metal matrix composite articles are secured together by at least surrounding the three dimensional array of elongated metal matrix composite articles with at least one of metal foil or graphite foil.