Al—Ce alloy based composites
MMC's comprising an Al-RB alloy-based matrix and ceramic, metal and/or intermetallic reinforcement particulates dispersed in the alloy matrix provide improved strength and ductility wherein the reinforcement particulates have a higher melting temperature than the matrix alloy.
1 . A metal matrix composite comprising an alloy matrix that comprises consolidated alloy powder having a composition comprising Al, RE, and Mg and containing reinforcement particulates in the form of reinforcement powder particles dispersed in the alloy matrix wherein the reinforcement particulates have a higher melting temperature than the alloy matrix; wherein a metallic interfacial reaction layer is present between the alloy matrix and individual reinforcement particulates and includes constituent elements of the alloy matrix and of the reinforcement particulates, wherein presence of the interfacial reaction layer facilitates load partitioning between the relatively soft alloy matrix and relatively hard reinforcement particulates; wherein the metal matrix composite exhibits tensile strength greater than that of the alloy matrix devoid of the reinforcement particulates; and wherein the reinforcement particulates comprise powder particles of at least one of Al 2 O 3 , Ni 3 Al, ZrO 2 , SiC, B 4 C, CeO 2 , and/or La 2 O 3 .
2 . The composite of claim 1 wherein the alloy matrix comprises about 1 to about 30 weight % RE material where RE material is selected from Ce, La, mischmetal, or any combination thereof, and balance aluminum (Al).
3 . The composite of claim 2 wherein the alloy matrix comprises about 1 to about 20 weight % RE material.
4 . The composite of claim 3 wherein the alloy matrix comprises about 1 to about 18 weight % RE material.
5 . The composite of claim 2 wherein the alloy matrix comprises at least one alloying element selected from the group consisting of Mg, Cu, Mn, Ca, Ni, Zr, Zn, Si, and Ti in a total amount of about 1 to about 14 weight %.
6 . The composite of claim 1 wherein the reinforcement powder particles are present in the alloy matrix in an amount of about 1 to about 40 volume %.
7 . The composite of claim 1 wherein the reinforcement powder particles are sieved to have an as-sieved minimum average diameter that is in the range of 0.01 microns to 250 microns.
8 . The composite of claim 1 which is at least one of an extruded composite, thermal sprayed composite, cold sprayed composite, additive manufactured composite, or electrodeposited composite.
9 . The composite of claim 1 wherein the alloy matrix comprises Mg alloying element present in a total amount of 1 to 12 weight % and a light rare earth element comprising at least one of Ce, or La, or both Ce and La in an amount of 18 weight % minus the weight % of the Mg alloying element.
10 . The composite of claim 1 wherein the interfacial reaction layer surrounds individual reinforcement particulates.
11 . The composite of claim 1 wherein the interfacial reaction layer is present as a physically distinct layer from the alloy matrix.
12 . A metal matrix composite comprising a Al-RE alloy matrix that comprises consolidated alloy powder having a composition comprising Al and RE and containing reinforcement particulates consisting of reinforcement powder particles in the alloy matrix wherein the reinforcement powder particles have a higher melting temperature than the alloy matrix; wherein a metallic interfacial reaction layer is present between the alloy matrix and the reinforcement particulates and includes constituent elements of the alloy matrix and of the reinforcement particulates wherein presence of the interfacial reaction layer facilitates load partitioning between the relatively soft alloy matrix and relatively hard reinforcement particulates; wherein the metal matrix composite exhibits tensile strength for load bearing greater than that of the alloy matrix devoid of the reinforcement powder particles, wherein the reinforcement powder particles are selected from Al 2 O 3 , Ni 3 Al, ZrO 2 , SiC, B 4 C, CeO 2 , or La 2 O 3 , and wherein the consolidated alloy powder forming the matrix comprises at least one additional alloying element selected from Mg, Cu and/or Mn.