Dendrite-Reinforced Titanium-Based Metal Matrix Composites

Patent metadata

Field	Value
Publication number	US-2018339342-A1
Application number	US-201815991854-A
Country	US
Kind code	A1
Filing date	May 29, 2018
Priority date	May 26, 2017
Publication date	Nov 29, 2018
Grant date	—

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 m 1/2 , a yield strength divided by the density greater than 200 MPa cm 3 /g, and a total strain to failure in a tension test greater than 5%.

First claim

1 . A method of fabricating a part thicker than 0.5 mm via layer-by-layer additive manufacturing comprising:
providing an alloy having at least 85 atomic % of at least Ti and at least one component selected from the group of Zr, Hf, Ta, Nb, V, and Mo, and one or more additional components, X, selected from the group of Co, Fe, Ni, Cu, Al, B, Ag, Pd, Au, Pd, C, Si, and Sn, wherein the atomic % of Ti is greater than any other single component; disposing molten layers of the alloy atop one another additively; cooling each layer prior to disposition of the next at a rate such that upon solidification the alloy segregates phases into a metal matrix composite consisting of isolated crystalline dendrites in a continuous eutectic matrix material; and repeating the disposing and cooling to form a metal matrix composite part.

2 . The method of claim 1 , wherein the alloy comprises a combination of Ti, Zr, a beta-stabilizer, where the atomic percentage of the Ti, Zr, and beta-stabilizer is between 85 to 98 atomic % of the alloy, and where X comprises from 2 to 15 atomic % of the alloy.

3 . The method of claim 2 , wherein the beta-stabilizer is selected from the group 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 a combination of Ti, one or both Zr and Hf, a beta-stabilizer, B, and X, where the combination of Ti, Zr and Hf, and the beta-stabilizer is between 85 to 98 atomic % of the alloy, where B comprises from between 0.5 to 5 atomic % of the alloy, and where X comprises less than 10 atomic % of the alloy.

6 . The method of claim 5 , wherein the beta-stabilizing components are selected from the group of V, Nb, Ta and Mo, and wherein X is selected from the group of Zr, B, Si, Cu, Co, Fe, and Pd.

7 . The method of claim 1 , wherein the thickness of each of the layer is from between 10-1000 micrometers.

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 crystalline dendrites comprise at least 60% by volume of the solidified alloy.

10 . The method of claim 1 , wherein the hardness of the matrix is at least 5% larger than the hardness of the dendrites.

11 . The method of claim 1 , wherein the composite part has at least one property selected from the group of a tensile strength of greater than 1 GPa, a fracture toughness of greater than 40 MPa m 12 , a density of less than 6.0 g/cm 3 , 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 formed by adding components to Ti.

13 . The method of claim 1 , wherein the solidus temperature of the alloy is less than 1600 Celsius.

14 . The method of claim 1 , wherein the crystalline dendrites range in size from 1 to 20 micrometers in diameter after solidification.

15 . The method of claim 1 , wherein the crystalline dendrites are less than 10 micrometers in diameter after solidification.

16 . The method of claim 1 , wherein the alloy is heated to a semi-solid temperature region between the alloy solidus and liquidus during disposition.

17 . The method of claim 1 , wherein the part is used in a structural application.

18 . The method of claim 1 , wherein the heating and cooling disposition parameters are altered between the disposition of at least two layers of the part such that the one of either the size or the density of the dendrites is altered within at least two layers of the part such that a gradient of properties is formed within the part.

19 . The method of claim 1 , wherein the disposition process is selected from one of powder bed fusion, direct energy deposition, laser foil welding, fused filament fabrication, electron beam fabrication, thermal spraying, and liquid deposition.

20 . The method of claim 1 , wherein the disposition process is selected from one of binder jetting, friction stir additive manufacturing, cold spraying, and ultrasonic additive manufacturing.

21 . The method of claim 1 , 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 %.

23 . The Ti-based alloy of claim 1 where the alloy is selected from the group 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 .

24 . The method of claim 1 , wherein the metal matrix component part is selected form the group of biomedical implants, structural aerospace components, sporting equipment, medical devices, and engine components.

25 . The method of claim 1 , wherein the matrix material and the crystalline dendrites are combined ex situ to form the metal matrix composite.

26 . The method of claim 25 , where the matrix material and crystalline dendrites are in the form of powders with a size distribution within 10% of each other.

Assignees

• California Inst Of Techn

Inventors

• Hofmann Douglas C

Classifications

• C22C14/00

  Alloys based on titanium · CPC title

• B22F2301/40

  Intermetallics other than rare earth-Co or -Ni or -Fe intermetallic alloys · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• C22C2200/04

  Nanocrystalline · CPC title