High-strength discontinuously-reinforced titanium matrix composites and method for manufacturing the same

Abstract

The invention relates to manufacturing the flat or shaped titanium matrix composite articles having improved mechanical properties such as lightweight plates, sheets for aircraft and automotive applications, heat-sinking lightweight electronic substrates, armor plates, etc. High-strength discontinuously-reinforced titanium metal matrix composite (TMMC) comprises (a) titanium matrix or titanium alloy as a major component, (b) ceramic and/or ≦50 vol. % intermetallic hard particles dispersed in matrix, (c) complex carbide- and/or boride particles at least partially soluble in matrix at sintering or forging temperatures such as ≦50 vol. % AlV 2 C, AlTi 2 Si 3 , AlTi 6 Si 3 , VB 2 , TiVSi 2 , TiVB 4 , Ti 2 AlC, AlCr 2 C, TiAlV 2 , V 2 C, VSi 2 , Ta 3 B 4 , NbTiB 4 , Al 3 U 2 C 3 dispersed in matrix. Method for manufacturing these TMMC materials is disclosed. Sintered TMMC density exceeds 98% and closed discontinuous porosity allows performing hot deformation in air without encapsulating. Near-full density near-net shape TMMC parts with acceptable mechanical properties were manufactured without hot deformation.

1 . A high-strength discontinuously-reinforced titanium matrix composite material comprising (a) a matrix of titanium or titanium alloy as a major component, (b) ceramic and/or intermetallic hard particles such as TiB 2  and/or SiC dispersed in the matrix in the amount of 50% or less by volume, and (c) complex carbide- and/or boride particles that are at least partially soluble in the matrix at the sintering or forging temperatures such as AlV 2 C, AlTi 2 Si 3 , AlTi 6 Si 3 , AlTi 4 Si 7 , Al 3 B 48 Si, VB 2 , V 3 B 2 , V 3 B 4 , TiVSi 2 , TiVB 4 , Ti 2 AlC, Ti 3 AlC, AlCr 2 C, TiAlV 2 , (Ti,V)C, (Ti,V)(B,C), V 2 C, V 4 C 3 , VSi 2 , Ta 3 B 4 , Ta 3 B 2 , Ti 2 Al(B,C), TaTiB 4 , NbTiB 4 , and/or Al 3 U 2 C 3  which are dispersed in the matrix in the amount of 20% by volume or less. 
     
     
         2 . A method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 1  comprises the following steps:
 (a) preparing a basic powdered blend containing the matrix alloy or titanium powders having a particle size less than 250 μm for 95% of the powder, and/or a mixture of the same titanium powder with the master alloy creating an alloyed titanium matrix, and powders which reinforce matrix during sintering or forging operations such as ceramic powders, intermetallic powders, and/or powders of complex carbide- and/or boride particles that are at least partially soluble in the matrix during the sintering, forging, or other high temperature operations, such as AlV 2 C, AlTi 2 Si 3 , AlTi 6 Si 3 , AlTi 4 Si 7 , Al— 3 B 48 Si, VB 2 , V 3 B 2 , V 3 B 4 , TiVSi 2 , TiVB 4 , Ti 2 AlC, Ti 3 AlC, AlCr 2 C, TiAlV 2 , (Ti,V)C, (Ti,V)(B,C), V 2 C, V 4 C 3 , VSi 2 , Ta 3 B 4 , Ta 3 B 2 , Ti 2 Al(B,C), TaTiB 4 , NbTiB 4 , and/or Al 3 U 2 C 3 ,   (b) preparing the reinforcing powders by co-attrition, mechanical alloying, and/or pre-sintering and grinding of elemental powders,   (c) mixing the basic powdered blend with the Al—V master alloy powder and/or mechanically-alloyed powders in the predetermined ratio to obtain a chemical composition of titanium matrix composite material,   (d) consolidating at room temperature the powder mixture containing incompletely-formed reinforcing particles by cold isostatic pressing, die pressing, direct powder rolling, or other processes,   (e) sintering at the temperature providing at least partial dissolution of dispersing ceramic and/or intermetallic powders to form the reinforcing particle system after the cooling,   (f) high-temperature deformation (forging, rolling, hot pressing, hot isostatic pressing, and/or others) in the temperature range of 1500-2300° F.,   (g) cooling.   
     
     
         3 . The high-strength discontinuously-reinforced titanium matrix composite material according to  claim 1  is characterized by discontinuous porosity at the density over 98% from the theoretical value. 
     
     
         4 . The high-strength discontinuously-reinforced titanium matrix composite material according to  claim 1 , wherein the matrix alloy is selected from the group consisting of α-titanium alloys, (α+β)-titanium alloys, β-titanium alloys, or titanium aluminide alloys. 
     
     
         5 . The high-strength discontinuously-reinforced titanium matrix composite material according to  claim 1 , wherein the ceramic and/or intermetallic hard particles dispersed in the matrix are selected from the group consisting of SiC, TiB, TiB 2 , Ti 3 B 4 , Ti 2 B 5 , B 4 C, ZrC, ZrB 2 , TaC, TaB, TaB 2 , Ta 3 B 2 , B 4 Si, B 6 Si, VB, V 2 B, WC, NbC, NbB, Nb 3 B 2 , Nb 3 B 4 , Al 4 C 3 , Al 4 C 3 , AlB 2 , TiAl, Ti 3 Al, TiAl 3 , Al 8 V 5 , VC, Cr 7 C 3 , HfC, UC, U 2 C 3 , and/or TiCr 2 . 
     
     
         6 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein the basic powdered blend is prepared in the form of elemental powder blend or combination of elemental powders and prealloyed powders blend. 
     
     
         7 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein co-attrition or mechanical alloying of reinforcing elemental powders is carried out with a partial addition of the master alloy in the amount up to 30 wt. % of the weight of reinforcing powders. 
     
     
         8 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein mechanical alloying is carried out with different dispersion effects, i.e. attrition for different time to create a particular particle size distribution of reinforcing particles. 
     
     
         9 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein the dispersing ceramic and/or intermetallic powders are selected from the group consisting of SiC, TiB, TiB 2 , Ti 3 B 4 , Ti 2 B 5 , B 4 C, ZrC, ZrB 2 , TaC, TaB, TaB 2 , Ta 3 B 2 , B 4 Si, B 6 Si, VB, V 2 B, WC, NbC, NbB, Nb 3 B 2 , Nb 3 B 4 , Al 4 C 3 , Al 4 C 3 , AlB 2 , TiAl, Ti 3 Al, TiAl 3 , Al 8 V 5 , VC, Cr 7 C 3 , HfC, UC, U 2 C 3 , and/or TiCr 2 . 
     
     
         10 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein boron and/or carbon powders are preliminary reacted with aluminum or aluminum-vanadium master alloy at 800-1100° C., then the obtained pre-sintered cake is ground in powder and added into the initial mixture of composite material components. 
     
     
         11 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein boron carbide and boron silicide powders are preliminary reacted with titanium powder at 1200-1400° C., then the obtained pre-sintered cake is ground in powder and added into the initial mixture of composite material components. 
     
     
         12 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein titanium boride and/or silicon carbide powders are preliminary reacted with aluminum or aluminum-vanadium master alloy at 900-1100° C., then the obtained pre-sintered cake is ground in powder and added into the initial mixture of composite material components. 
     
     
         13 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein carbon powder is introduced in amount of up to 30 wt. % in the basic powder blend, whereby the carbon is in the form of graphite, black carbon, or pyrolytic carbon. 
     
     
         14 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein the sintering is carried out at the temperature of 2300° F. (1260° C.) and higher to provide complete densification and provide oversaturated solid solution that will result in the formation of coherent reinforced carbidic and/or intermetallic particles in the matrix alloy during the cooling. 
     
     
         15 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein hot pressing, hot isostatic pressing, or hot rolling are carried out after sintering in any combination. 
     
     
         16 . The method for manufacturing the high-strength discontinuously-reinforced titanium matrix composite material according to  claim 2 , wherein the resulting composite material is characterized by density over 98% of theoretical value and discontinued porosity after sintering that makes it possible forging, hot pressing, hot isostatic pressing, or hot rolling without any special protective coating, encapsulating, or canning. 
     
     
         17 . Use of the high-strength titanium matrix composite material manufactured according to  claim 2 , wherein the as-sintered state that is characterized by density over 98% of theoretical value and discontinued porosity. 
     
     
         18 . Use of the high-strength titanium matrix composite material manufactured according to  claim 2 , wherein the near-net shape state after forging, hot pressing, hot isostatic pressing, or hot rolling performed without any special protective coating, encapsulating, or canning, and without finishing of final product by machining and/or chemical milling.