Dendrite-Reinforced Titanium-Based Metal Matrix Composites

Abstract

Ti-based metal matrix composites, methods of their additive manufacture, and parts manufactured therefrom and thereby are provided. Method include layer-by-layer additive manufacturing for fabricating Ti-based metal matrix composite parts thicker than 0.5 mm, in layers with thickness between 10-1000 micrometers. The parts formed may have one or more of the following properties: a tensile strength greater than 1 GPa, a fracture toughness greater than 40 MPa m1/2, a yield strength divided by the density greater than 200 MPa cm3/g, and a total strain to failure in a tension test greater than 5%.

1 . A method of manufacturing a part comprising a metal composite material comprising:
 providing an alloy comprising Ti at least one β-stabilizer, wherein a β-stabilizer is an element selected from the group consisting of Zr, Hf, Ta, Nb, V, Sn, and Mo; and X, wherein X represents one or more additional elements selected from the group consisting of Co, Fe, Ni, Cu, Al, B, Ag, Pd, Au, Pd, C, and Si wherein the atomic % of Ti in the alloy is greater than the amount of any other element in the alloy, wherein the combined amounts of Ti and the at least one β-stabilizer comprise at least 85 atomic % of the alloy, and wherein the alloy does not contain Be;   depositing a molten portion of the alloy; and   cooling the molten portion at a cooling rate such that upon solidification the alloy segregates phases to produce a metal matrix composite comprising a plurality of isolated crystalline dendrites characterized by a dendrite size and a dendrite density dispersed within a continuous crystalline eutectic material matrix.   
     
     
         2 . The method of  claim 1 , wherein the alloy comprises Ti, Zr, at least one additional beta-stabilizer, and X; and wherein the atomic % of the sum of Ti, Zr, and the at least one additional beta-stabilizer comprises between 85 and 98 atomic % of the alloy, and X comprises from 2 and 15 atomic % of the alloy. 
     
     
         3 . The method of  claim 2 , wherein the at least one additional beta-stabilizer is selected from the group consisting of V, Nb, Ta and Mo. 
     
     
         4 . The method of  claim 1 , wherein Ti comprises at least 50 atomic % of the alloy. 
     
     
         5 . The method of  claim 1 , wherein the alloy comprises Ti, one or both Zr and Hf, at least one additional beta-stabilizer, B, and at least one additional X; wherein the sum of Ti, the on or both Zr and Hf, and the at least one additional beta-stabilizer comprises between 85 and 98 atomic % of the alloy, B comprises between 0.5 and 5 atomic % of the alloy, and X comprises less than 10 atomic % of the alloy. 
     
     
         6 . The method of  claim 5 , wherein the at least one additional beta-stabilizer is selected from the group consisting of V, Nb, Ta and Mo, and the at least one additional X is selected from the group consisting of Si, Cu, Co, Fe, and Pd. 
     
     
         7 . (canceled) 
     
     
         8 . The method of  claim 1 , wherein the cooling rate is greater than 10 2  K/s. 
     
     
         9 . The method of  claim 1 , wherein the plurality of isolated crystalline dendrites comprises at least 60% by volume of the solidified alloy. 
     
     
         10 . The method of  claim 1 , wherein the continuous crystalline eutectic material matrix is characterized by a matrix hardness and the plurality of isolated crystalline dendrites is characterized by a dendrite hardness, and wherein the matrix hardness is at least 5% larger than the dendrite hardness. 
     
     
         11 . The method of  claim 1 , wherein the metal matrix composite part has at least one property selected from the group consisting of: a tensile strength of greater than 1 GPa, a fracture toughness of greater than 40 MPa m 1/2 , a density of less than 6.0 g/cm 3 , a total strain to failure of greater than 5% in a tension test, and a yield strength divided by the density greater than 200 MPa cm 3 /g. 
     
     
         12 . The method of  claim 1 , wherein the alloy is characterized by a solidus temperature of less than 1600 Celsius. 
     
     
         13 . The method of  claim 1 , wherein the dendrite size ranges from 1 to 20 micrometers in diameter. 
     
     
         14 . The method of  claim 13 , wherein the dendrite size is less than 10 micrometers in diameter. 
     
     
         15 . The method of  claim 1 , wherein depositing further includes heating the alloy portion to a semi-solid temperature region between the alloy's solidus and liquidus. 
     
     
         16 . The method of  claim 1 , wherein the metal matrix composite part is used in a structural application. 
     
     
         17 . The method of  claim 1 , wherein the part is used in a structural alloy is selected from the group consisting of Ti 74 V 10 Zr 10 Si 6 , Ti 64 V 10 Zr 20 Si 6 , Ti 71 V 10 Zr 10 Si 6 Al 3 , Ti 74 Nb 10 Zr 10 Si 6 , Ti 74 Ta 10 Zr 10 Si 6 , Ti 75 CU 7 Ni 6 Sn 2 V 10 , Ti 75 CU 7 Ni 6 Sn 2 Nb 10 , Ti 75 CU 7 Ni 6 Sn 2 Ta 10 , (Ti 72 Zr 22 Nb 6 ) 95 Co 5 , (Ti 72 Zr 22 Nb 6 ) 92 Co 5 Al 3 , (Ti 72 Zr 22 Ta 6 ) 95 Co 5 , (Ti 72 Zr 22 Ta 6 ) 92 Co 5 Al 3 , (Ti 72 Zr 22 V 6 ) 95 Co 5 , (Ti 72 Zr 22 V 6 ) 92 Co 5 Al 3 , Ti 90 Nb 5 Cu 5 , Ti 85 Nb 10 Cu 5 , Ti 80 Nb 5 Cu 10 , Ti 80 Nb 10 Cu 10 , Ti 90 Ta 5 Cu 5 , Ti 85 Ta 10 Cu 5 , Ti 80 Ta 5 Cu 10 , Ti 80 Ta 10 Cu 10 , Ti 90 V 5 Cu 5 , Ti 85 V 10 Cu 5 , Ti 80 V 5 Cu 10 , Ti 80 V 10 Cu 10 , Ti 85 V 10 B 5 , Ti 85 Ta 10 B 5  and Ti 85 Nb 10 B 5 , Ti 57 Zr 18 V 12 Cu 10 Al 3  or Ti 62 Zr 18 V 12 Cu 5 Al 3 . 
     
     
         18 . The method of  claim 1 , wherein the metal matrix composite part is a type of a part selected form the group consisting of: biomedical implant, structural aerospace component, sporting equipment, medical device, and engine component. 
     
     
         19 . The method of  claim 1 , wherein the cooled portion forms a metal matrix composite part with a thickness of at least 0.5 mm. 
     
     
         20 . A method of manufacturing a metal composite part comprising:
 providing a metal composite material comprising:
 an alloy comprising Ti; at least one β-stabilizer, wherein a β-stabilizer is an element selected from the group consisting of Zr, Hf, Ta, Nb, V, Sn, and Mo; and X, wherein X represents one or more additional elements selected from the group consisting of Co, Fe, Ni, Cu, Al, B, Ag, Pd, Au, Pd, C, and Si; wherein the atomic % of Ti in the alloy is greater than the amount of any other element in the alloy, wherein the combined amounts of Ti and the at least one β-stabilizer comprise at least 85 atomic % of the alloy; and wherein the alloy does not contain Be, wherein the alloy is segregated into phases comprising a plurality of isolated crystalline dendrites dispersed within a continuous crystalline eutectic material matrix; and 
   depositing and forming a portion of the metal composite material without heating to form a metal matrix composite part with a thickness of at least 0.5 mm.   
     
     
         21 . The method of  claim 20 , where the alloy comprises Ti, Nb and from 2 to 15 atomic % B. 
     
     
         22 . The method of  claim 21 , wherein the concentration of B is 5 atomic %.