| abstract |
A method is taught for the formation of intermetallic-second phase composite materials. The method involves the formation of a first metal-second phase composite comprising a relatively high loading of discrete, second phase particles distributed throughout a metal matrix, dilution of the first composite into an additional amount of metal to form a second composite comprising a lower loading of second phase particles within an intermediate metal matrix, and introduction of the second composite into another metal which is reactive with the intermediate metal matrix of the composite to form an intermetallic. A final intermetallic-second phase composite is thereby formed comprising a dispersion of discrete second phase particles throughout a final intermetallic matrix. The final intermetallic matrix may comprise a wide variety of intermetallic materials, with particular emphasis drawn to the aluminides and silicides. Exemplary intermetallics include Ti 3 Al, TiAl, TiAl 3 , Ni 3 Al, NiAl, Nb 3 Al, NbAl 3 , Co 3 Al, Zr 3 Al, Fe 3 Al, Ta 2 Al, TaAl 3 , Ti 5 Si 3 , Nb 5 Si 3 , Cr 3 Si, CoSi 2 and Cr 2 Nb. The second phase particulate materials may comprise ceramics, such as a borides, carbides, nitrides, oxides, silicides or sulfides, or may comprise an intermetallic other than the matrix intermetallic. Exemplary second phase particulates include TiB 2 , ZrB 2 , HfB 2 , VB 2 , NbB 2 , TaB 2 , MoB 2 , TiC, ZrC, HfC, VC, NbC, TaC, WC, TiN, Ti 5 Si 3 , Nb 5 Si 3 , ZrSi 2 , MoSi 2 , and MoS 2 . |