Titanium alloy

Abstract

A titanium alloy comprises, in weight percent based on the total alloy weight: 3.5 to 4.5 aluminum; 1.0 at least less than 3 of tin; zirconium from 1.0 to 3.0; from 2.0 to 5.5 of molybdenum; 2.0 to 4.25% of chromium; from 0.01 to 0.03 of silicon; titanium; and impurities; and wherein the titanium alloy has an aluminum equivalent value of 6.0 to 6.9.

Description

Technical Field

[0001] This disclosure relates to titanium alloys, methods for preparing titanium alloys, and articles comprising titanium alloys. Background Technology

[0002] Existing titanium alloys used in structural applications requiring high strength and toughness include, for example, Ti-6Al-4V alloy (UNS R56400, “Ti-64”) and Ti-5Al-2Sn-2Zr-4Mo-4Cr alloy (UNS R58650, “Ti-17”). These alloys exhibit favorable toughness at room temperature along with high tensile properties (yield strength, ultimate tensile strength, and ductility). The Ti-17 alloy, for example, exhibits fracture toughness at room temperature (approximately 55.5 ksi√inch) and a desirable combination of YS and UTS of 161 ksi and 157 ksi, respectively. Developing titanium alloys that exhibit improved toughness while maintaining the desired tensile properties presents a significant challenge. Summary of the Invention

[0003] According to a non-limiting aspect of this disclosure, a titanium alloy comprises, by weight percentage based on the total alloy weight: 3.5 to 4.5% aluminum; 1.0% at least 3.0% tin; 1.0 to 3.0% zirconium; 2.0 to 5.5% molybdenum; 2.0 to 4.25% chromium; 0.01 to 0.03% silicon; titanium; and impurities; and wherein the aluminum equivalent of the titanium alloy is 6.0 to 6.9%.

[0004] According to another non-limiting aspect of this disclosure, there is a titanium alloy comprising, by weight percentage based on the total alloy weight: 4.2 to 4.4% aluminum; 1.2 to 1.75% tin; 1.2 to 1.75% zirconium; 4.0 to 4.25% molybdenum; 4.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 1.0 to 2.0% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities; and wherein the aluminum equivalent of the titanium alloy is 6.1 to 6.9%.

[0005] According to yet another non-limiting aspect of this disclosure, a titanium alloy comprises, by weight percentage based on the total alloy weight: 3.65 to 4.4% aluminum; 1.2 to 2.5% tin; 1.2 to 2.2% zirconium; 3.0 to 4.25% molybdenum; 3.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 0 to 2.0% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities. The titanium alloy has an aluminum equivalent of 6.1 to 6.5 and a molybdenum equivalent of 4.8 to 10.9. The titanium alloy exhibits a yield strength of at least 137 ksi, an ultimate tensile strength of at least 148 ksi, and a fracture toughness of at least 85 ksi√(inch).

[0006] According to another non-limiting aspect of this disclosure, a method for manufacturing a titanium alloy is disclosed. The method comprises solution treating the titanium alloy by heating it at 800°C to 860°C for 1 to 8 hours, and subsequently cooling it to ambient temperature at a rate determined by the cross-sectional thickness of the titanium alloy. After cooling, the titanium alloy is aged by heating it at 480°C to 700°C for 4 to 16 hours, and then air-cooling the aged alloy. In some embodiments, the titanium alloy comprises, by weight percentage based on the total alloy weight: 3.5 to 4.5% aluminum; 1.0% at least 3.0% tin; 1.0 to 3.0% zirconium; 2.0 to 5.5% molybdenum; 2.0 to 4.25% chromium; 0.01 to 0.03% silicon; titanium; and impurities; and wherein the aluminum equivalent of the titanium alloy is 6.0 to 6.9.

[0007] According to another non-limiting aspect of this disclosure, there is a product comprising a titanium alloy. In some embodiments, the titanium alloy comprises, by weight percentage based on the total alloy weight: 3.5 to 4.5% aluminum; 1.0% at least 3.0% tin; 1.0 to 3.0% zirconium; 2.0 to 5.5% molybdenum; 2.0 to 4.25% chromium; 0.01 to 0.03% silicon; titanium; and impurities; and wherein the aluminum equivalent of the titanium alloy is 6.0 to 6.9.

[0008] It should be understood that the invention disclosed and described in this specification is not limited to the aspects outlined in this summary. The foregoing details, as well as other details, will be understood after considering the following detailed description of various non-limiting and non-exhaustive aspects according to this specification. Attached Figure Description

[0009] The features and advantages of the examples presented herein, as well as the ways in which these features and advantages are obtained, will become more apparent and the examples will be better understood by referring to the following description in conjunction with the accompanying drawings, wherein:

[0010] Figure 1 Electron microscopy images of the alloy of Example Composition 1 after thermomechanical processing, solution treatment, and aging treatment, wherein the α laths appear as light-colored elongated shapes in a dark β matrix due to the application of a standard nitric acid / hydrofluoric acid etchant;

[0011] Figure 2 The images are electron microscope images of the alloy of Example Composition 2 after thermomechanical processing, solution treatment, and aging treatment, wherein the α laths appear as light-colored elongated shapes in the dark β matrix due to the application of a standard nitric acid / hydrofluoric acid etchant; and

[0012] Figure 3 The image shows an electron microscope image of an alloy of Example Composition 1 after thermomechanical processing, solution treatment, and aging treatment, wherein the α-lamellae appear as light-colored elongated shapes in a dark β-matrix due to the application of a standard nitric acid / hydrofluoric acid etchant.

[0013] The examples set forth herein illustrate certain embodiments in one form, and such examples should not be construed as limiting the scope of the appended claims in any way. Detailed Implementation

[0014] This document describes and illustrates various embodiments to provide a general understanding of the disclosed titanium alloys, methods, and articles. The various embodiments described and illustrated herein are non-limiting and non-exhaustive. Therefore, the invention is not limited to the description of the various non-limiting and non-exhaustive embodiments disclosed herein. Rather, the invention is defined solely by the claims.

[0015] The features and characteristics illustrated and / or described in connection with the various embodiments may be combined with features and characteristics of other embodiments. Such modifications and variations are intended to be included within the scope of this specification. Therefore, the claims may be amended to state any feature or characteristic expressly or inherently described in this specification or otherwise expressly or inherently supported by this specification. Furthermore, the applicant reserves the right to amend the claims to expressly waive any rights to features or characteristics that may exist in the prior art.

[0016] The various embodiments disclosed and described in this specification may include, constitute, or substantially constitute the features and characteristics as described herein differently. For example, the reference herein to titanium alloys “comprising” a specific elemental composition is intended to also cover alloys that are “substantially composed of” or “consistent with” the stated composition. It should be understood that titanium alloy compositions described herein that are “comprising a specific composition,” “consistent with” or “substantially composed of” a specific composition may also include impurities.

[0017] Unless otherwise stated herein, all element concentrations provided herein for alloy compositions are weight percentages based on the total weight of the particular alloy composition.

[0018] The high-temperature properties and fracture toughness of titanium alloys can depend on their microstructural characteristics. Titanium exists in two allotropic forms: the β (“beta”) phase, which has a body-centered cubic (“bcc”) crystal structure; and the α (“alpha”) phase, which has a hexagonal close-packed (“hcp”) crystal structure. A group of titanium alloys widely used in various applications is α / β titanium alloys. In α / β titanium alloys, the distribution and size of the primary α particles can directly affect high-temperature properties and fracture toughness.

[0019] Improving the toughness of a material while maintaining or enhancing its tensile properties can be challenging. However, enhancing the fracture toughness of titanium alloys while maintaining and / or improving their tensile properties can enable novel component designs exhibiting higher damage tolerance. The titanium alloy examples presented herein demonstrate enhanced fracture toughness relative to some existing titanium alloys while maintaining acceptable tensile properties.

[0020] The inventors have determined that the fracture toughness and tensile strength of titanium alloys can be enhanced by controlling their chemical composition and / or microstructure. The titanium alloys described herein may be α / β titanium alloys, which may include a balanced α-stabilizer and β-stabilizer, as well as a desired aluminum equivalent value (Al). 当量 ) and / or molybdenum equivalent (Mo) 当量 The titanium alloy compositions according to this disclosure can suppress the formation of problematic intermetallic phases (e.g., Ti3Al, silicides), which can enhance the microstructure formed in the alloy. The fracture toughness and tensile strength properties of the titanium alloys according to this disclosure can be enhanced by providing a reduced aluminum content relative to certain titanium alloys; and by including, for example, the addition of tin and zirconium to provide the desired aluminum equivalent value (Al). 当量The titanium alloys according to this disclosure exhibit solid solution strengthening while balancing the effects of the shear modulus mismatch between solute and solvent atoms in a given phase.

[0021] According to certain non-limiting embodiments of the titanium alloy of this disclosure, the alloy comprises, by weight percentage based on the total weight of the titanium alloy: 3.5 to 4.5% aluminum; 1.0% at least 3.0% tin; 1.0 to 3.0% zirconium; 2.0 to 5.5% molybdenum; 2.0 to 4.25% chromium; 0.01 to 0.03% silicon; titanium; and impurities; and wherein the aluminum equivalent of the titanium alloy is 6.0 to 6.9%.

[0022] Other non-limiting embodiments of the titanium alloy according to this disclosure comprise, by weight percentage based on the total weight of the titanium alloy: 3.5 to 4.5% aluminum; 1.0% at least 3.0% tin; 1.0% to 3.0% zirconium; 2.0% to 5.5% molybdenum; 2.0% to 4.25% chromium; 0.01% to 0.03% silicon; 0% to 0.30% iron; 0% to 0.20% oxygen; 0% to 0.5% nitrogen; 0% to 0.0125% hydrogen; 0% to 0.08% carbon; 0% to 2% vanadium; 0% at least 0.1% germanium; 0% to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities.

[0023] Other non-limiting embodiments of the titanium alloy according to this disclosure contain, by weight percentage based on the total weight of the titanium alloy: 3.65 to 4.4% aluminum; 1.2 to 2.5% tin; 1.2 to 2.2% zirconium; 3.0 to 4.25% molybdenum; 3.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 0 to 2% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities.

[0024] Other non-limiting embodiments of the titanium alloy according to this disclosure comprise, by weight percentage based on the total weight of the titanium alloy: 4.2 to 4.4% aluminum; 1.2 to 1.75% tin; 1.2 to 1.75% zirconium; 4.0 to 4.25% molybdenum; 4.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 1 to 2% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities; and wherein the aluminum equivalent of the titanium alloy is 6.1 to 6.9%.

[0025] Other non-limiting embodiments of the titanium alloy according to this disclosure contain, by weight percentage based on the total weight of the titanium alloy: 3.65 to 4.4% aluminum; 1.2 to 2.5% tin; 1.2 to 2.2% zirconium; 3.0 to 4.25% molybdenum; 3.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 0 to 2% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities.

[0026] In various embodiments of the titanium alloys according to this disclosure, the aluminum equivalent value may range from 6.1 to 6.9 or 6.1 to 6.5, and the molybdenum equivalent value may range from 4.8 to 10.9. In various embodiments, the titanium alloys according to this disclosure may exhibit a yield strength of at least 137 ksi, an ultimate tensile strength of at least 148 ksi, and a fracture toughness of at least 85 ksi√(inches).

[0027] Aluminum can be included in the titanium alloys according to this disclosure to increase the α content and / or improve the strength of the alloy. However, the aluminum content in the alloys of the present invention can be limited to a level that would inhibit the formation of intermetallic phases (e.g., Ti3Al phase), which may reduce the ductility and / or toughness properties of the alloy. Certain non-limiting embodiments of the titanium alloys according to this disclosure may contain 3.5% to 4.5% aluminum by weight percentage based on the total weight of the titanium alloy, for example, 3.6% to 4.5%, 3.6% to 4.4%, 3.65% to 4.4%, 3.8% to 4.4%, 4.0% to 4.4%, or 4.2% to 4.4% aluminum.

[0028] Tin may be included in titanium alloys according to this disclosure to increase the α content, improve strength, and / or adjust the aluminum equivalent value (Al) of the alloy. 当量 According to certain non-limiting embodiments of the titanium alloy of this disclosure, it may contain at least 1.0% to 3.0% tin as a weight percentage based on the total weight of the titanium alloy, for example, 1.0% to 2.9%, 1.0% to 2.8%, 1.0% to 2.5%, 1.2% to 2.5%, 1.5% to 2.5%, 1.5% to 2.3%, or 1.4% to 1.7% tin.

[0029] Molybdenum, chromium, and vanadium are primary β-strengtheners and can be included in embodiments of the alloys according to this disclosure to enhance tensile strength and / or fracture toughness. For example, chromium can be effectively used to strengthen the β phase due to the mismatch between the shear modulus of chromium and that of titanium. Certain non-limiting embodiments of the titanium alloys according to this disclosure may contain 2.0% to 4.25% chromium by weight percentage based on the total weight of the titanium alloy, for example, 3.0% to 4.25%, 3.5% to 4.25%, or 4.0% to 4.25% chromium.

[0030] Molybdenum can be included in the titanium alloys according to this disclosure to increase the β content and / or improve the tensile strength. Certain non-limiting embodiments of the titanium alloys according to this disclosure may contain 2.0% to 5.5% molybdenum by weight percentage based on the total weight of the titanium alloy, for example, 2.0% to 5%, 2.0% to 4.5%, 2.0% to 4.25%, 3.0% to 4.5%, 3.0% to 4.5%, 3.0% to 4.25%, 3.5% to 4.5%, 4.0% to 4.5%, or 4.0% to 4.4% molybdenum.

[0031] Some non-limiting embodiments of the titanium alloys according to this disclosure may contain 0% to 2% vanadium as a weight percentage based on the total weight of the titanium alloy, for example, 0.5% to 2%, 1% to 2%, or 1.4% to 1.8% vanadium.

[0032] Zirconium can be included in titanium alloys according to this disclosure to increase the α content, provide improved strength, and / or adjust the aluminum equivalent value (Al) of the alloy. 当量 According to certain non-limiting embodiments of the titanium alloy disclosed herein, it may contain 1.0% to 3.0% zirconium by weight percentage based on the total weight of the titanium alloy, for example, 1% to 2.5%, 1% to 2%, 1.5% to 2.5%, 1.5% to 2.5%, or 1.4% to 1.9% zirconium.

[0033] The silicon content of the titanium alloys according to embodiments of the present disclosure can be limited to suppress the formation of silicide networks on β grain boundaries, which may reduce ductility and toughness. Certain non-limiting embodiments of the titanium alloys according to the present disclosure may contain 0.01% to 0.03% silicon by weight percentage based on the total weight of the titanium alloy, for example, 0.01% to 0.025%, 0.014% to 0.03%, 0.02% to 0.03%, or 0.14% to 0.025% silicon.

[0034] The germanium content in the titanium alloys according to embodiments of the present disclosure can be limited to suppress the formation of germanium-containing intermetallic precipitates. For example, in some embodiments of the alloys of the present invention, germanium may be intentionally not added to the titanium alloy, and the germanium may be absent or may be present only as an impurity. If present, the germanium content in the alloys of the present invention is less than 0.1% by weight. Some non-limiting embodiments of the titanium alloys according to the present disclosure may contain at least 0% to 0.1% germanium by weight percentage based on the total weight of the titanium alloy, for example, 0% to 0.09%, 0% to 0.08%, 0% to 0.05%, 0% to 0.02%, or 0% to 0.01% germanium.

[0035] Certain non-limiting embodiments of the titanium alloys according to this disclosure may contain one or more other elements, such as niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, and cobalt. Certain alloy embodiments according to this disclosure may contain 0% to 0.1% of each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, and cobalt.

[0036] Titanium alloys according to this disclosure may include impurities. Impurities may be present in the alloy due to impurities in, for example, starting materials (e.g., recycled waste materials) and / or processing of the alloy during production. In various non-limiting embodiments of the titanium alloys according to this disclosure, one or more of the following elements may be present as impurities: sulfur, phosphorus, calcium, bismuth, lead, antimony, selenium, arsenic, silver, tellurium, thallium, zinc, ruthenium, platinum, rhodium, palladium, osmium, iridium, gold, fluorine, and chlorine. If present, the impurity element is typically present at an individual concentration of no more than 0.1% by weight, and the total content of such impurities is typically no more than 0.5% by weight, all based on the total alloy weight. It should be understood that the foregoing list of impurity elements need not include all elements that may be present as impurities in the alloys according to this disclosure.

[0037] Certain non-limiting embodiments of the titanium alloys according to this disclosure may not require additional low gap (“ELI”) while exhibiting enhanced fracture toughness. Therefore, certain embodiments of the titanium alloys according to this disclosure may require less manufacturing control during processing and / or may be manufactured from starting materials of lower purity. Certain non-limiting embodiments of the titanium alloys according to this disclosure may contain 0% to 0.30% iron, 0% to 0.20% oxygen, 0% to 0.5% nitrogen, 0% to 0.0125% hydrogen, and / or 0% to 0.08% carbon by weight percentage based on the total alloy weight. For example, certain non-limiting embodiments of the titanium alloys according to this disclosure may contain more than 0.13% oxygen while still exhibiting enhanced fracture toughness relative to certain existing titanium alloys.

[0038] In certain embodiments of the alloys according to this disclosure, a proper balance between aluminum, zirconium, and tin can be achieved through the aluminum equivalent value (Al).当量 To determine. Al 当量 The following formula is used to calculate [Al], [Zr], [Sn], [O], [N], and [C], where [Al], [Zr], [Sn], [O], [N], and [C] refer to the weight percentage of the corresponding elements in the titanium alloy:

[0039]

[0040] The aluminum equivalent (Al) values ​​of titanium alloys according to certain non-limiting embodiments of the present disclosure 当量 It is in the range of 6.0 to 6.9, for example, 6.1 to 6.9, 6.1 to 6.5, 6.0 to 6.4 or 6.1 to 6.4.

[0041] In certain embodiments of the alloys according to this disclosure, a suitable balance between molybdenum, chromium, and vanadium, and optionally cobalt and niobium, can be achieved by measuring the molybdenum equivalent value (Mo). 当量 To determine. Mo 当量 The following formula is used to calculate [Mo], [Ta], [Nb], [W], [V], [Cr], [Ni], [Mn], [Co], and [Fe], where [Mo], [Ta], [Nb], [W], [V], [Cr], [Ni], [Mn], [Co], and [Fe] refer to the weight percentage of the corresponding elements in the titanium alloy.

[0042]

[0043] According to certain non-limiting embodiments of the titanium alloys disclosed herein, the molybdenum equivalent (Mo) values ​​are... 当量 It is in the range of 4.8 to 10.9, for example, 7.0 to 10.9, 8.0 to 10.9, 9.0 to 10.9 or 10.0 to 10.9.

[0044] The microstructures of the titanium alloys according to various embodiments of this disclosure provide an advantageous combination of yield strength, ultimate tensile strength, and fracture toughness properties. These microstructures are characterized by the presence of long primary α laths and very little to no grain boundary α-Ti precipitation.

[0045] In some non-limiting embodiments, the titanium alloys according to this disclosure exhibit a yield strength of at least 137 ksi, for example, at least 140 ksi, at least 141 ksi, at least 145 ksi, at least 146 ksi, or at least 148 ksi. In some non-limiting embodiments, the titanium alloys according to this disclosure may exhibit an ultimate tensile strength of at least 148 ksi, for example, at least 150 ksi, at least 155 ksi, or at least 156 ksi. Yield strength and ultimate tensile strength can be measured according to ASTM E8 / E8M-22. Yield strength and ultimate tensile strength can be measured at room temperature (e.g., 72℉ + / - 2℉).

[0046] In some non-limiting embodiments, the titanium alloys according to this disclosure can exhibit fracture toughness of at least 85 ksi√(inch), for example, at least 87 ksi√(inch), at least 89 ksi√(inch), at least 90 ksi√(inch), at least 92 ksi√(inch), at least 95 ksi√(inch), or at least 97 ksi√(inch). For example, various embodiments of the titanium alloys according to this disclosure can exhibit fracture toughness in the range of 89 ksi√(inch) to 100 ksi√(inch), such as 90 ksi√(inch) to 100 ksi√(inch) or 92 ksi√(inch) to 100 ksi√(inch). Fracture toughness can be measured according to ASTM E399. Fracture toughness can be measured at room temperature (e.g., 72℉ + / - 2℉).

[0047] The titanium alloys according to embodiments of this disclosure can be produced by casting the material through plasma arc melting (PAM), vacuum arc remelting (VAR), electron beam cooling bed, or a combination thereof to form a substantially homogeneous ingot.

[0048] For example, embodiments of the titanium alloy according to this disclosure can be produced by PAM, optionally followed by VAR (e.g., PAM+VAR), and casting to form a substantially homogeneous ingot. The ingot can be thermomechanically processed by forging, rolling, extrusion, stretching, swaging, hot isostatic pressing, upsetting, annealing, and / or other hot working techniques to achieve the desired microstructure. For example, the ingot can be subjected to a sequence including: a first β-forging step above the β-transformation temperature of the titanium alloy, an α+β-forging step below the β-transformation temperature (which may induce recrystallization), and a second β-forging step above the β-transformation temperature of the titanium alloy.

[0049] Following thermomechanical processing of the alloy, in various embodiments, the alloy may be heat-treated, for example, by solution treatment and aging. Solution treatment may be performed, for example, at a temperature 50°F to 150°F below the β-transformation temperature of the titanium alloy to provide the desired primary α volume fraction. Aging treatment may be performed at temperatures below the solution treatment temperature to promote the fine precipitation of the secondary α phase. In some non-limiting embodiments, the titanium alloy may be thermomechanically processed and / or heat-treated as described in U.S. Patent No. 10,913,991 or U.S. Patent No. 11,384,413, both of which are hereby incorporated by reference. Those skilled in the art will be able to determine a suitable sequence of steps for casting, thermomechanical processing, and heat treatment of the alloy according to this disclosure to impart the desired mechanical properties.

[0050] For example, an embodiment of the process for manufacturing a titanium alloy according to this disclosure may include solution treatment of the titanium alloy at a temperature ranging from 800°C to 860°C for 1 to 8 hours. Subsequently, the titanium alloy may be cooled to ambient temperature at a certain rate (to prevent cracking) depending on its cross-sectional thickness. The titanium alloy may be aged at a temperature ranging from 480°C to 700°C for 4 to 16 hours, followed by air cooling.

[0051] Rolled products comprising alloys according to this disclosure may include, for example, foils, sheets, plates, wires, billets, bars, rods, thick plates, ingots, forgings, castings, and powders. Those skilled in the art, considering the present description of the alloys of the present invention, will be able to determine, without much experimentation, a suitable sequence of steps for casting, thermomechanical processing, heat treatment, and further processing of the alloys according to this disclosure to provide rolled products of the alloys having desired mechanical properties.

[0052] The potential applications of the titanium alloys according to this disclosure are numerous. For example, the titanium alloys described herein are advantageously suited for a variety of applications where fracture toughness is important. Particularly advantageous articles made from the titanium alloys according to this disclosure include certain aerospace and aviation applications, including, for example, jet engine turbine disks and turbofan engine blades. Those skilled in the art will be able to manufacture such parts and other articles using the alloys according to this disclosure without requiring further description herein. The foregoing examples of possible applications of the alloys according to this disclosure are provided by way of example only and do not exhaustively describe all possible applications of the alloys of the invention. Additional applications of the alloys herein can be readily identified by those skilled in the art upon consideration of this disclosure.

[0053] Example

[0054] The following examples are intended to describe certain non-limiting embodiments and are not intended to limit the scope of this disclosure. Those skilled in the art will understand that variations of the following examples may be within the scope of this disclosure.

[0055] Example alloy compositions 1, 2, and 3 according to this disclosure were prepared by PAM + VAR treatment and thermomechanical processing into billets. The billets were subjected to solution treatment and aging treatment. Chemical analysis was performed on the solution-treated and aging-treated billets, and the results are shown in Table 1. Table 1 also shows literature values ​​for several existing commercially available alloys.

[0056] Table 1: Elemental Composition

[0057]

[0058]

[0059] Some impurities may already be present below the measurable analytical measurement result.

[0060] The ultimate tensile strength (UTS), yield strength (YS), elongation percentage, and fracture toughness of example alloy compositions 1, 2, and 3 were measured, and these values ​​are shown in Table 2. UTS and YS were measured according to ASTM E8 / E8M-22. Fracture toughness was measured according to ASTM E399. Elongation percentage was measured according to ASTM E8 / E8M-22.

[0061] Table 2. Mechanical properties (at 72℉)

[0062]

[0063] 1. Measured.

[0064] 2. Not measured; data from SAE AMS 4986F.

[0065] 3. Not measured; data from [source missing]. Materials Properties Handbook (Titanium Alloys) Titanium Alloys Edited by R. Boyer, G. Welsch, and EW Collins, ASM Inc., 1994.

[0066] 4. Not measured; data from AMS 4905F.

[0067] Example alloy compositions 1, 2, and 3 were observed to exhibit a favorable balance between fracture toughness and tensile properties, which is likely a result of the alloy's chemical composition and microstructure. The microstructures of example alloy compositions 1, 2, and 3 are shown in electron micrographs of the prepared samples illustrated in the accompanying figures. Figure 1 Electron micrographs of example alloy composition 1 are included. Figure 2 This is an electron micrograph of example alloy composition 2. Figure 3 This is an electron micrograph of example alloy composition 3. (Example:) Figure 1-3 As shown, the microstructure of the alloy sample comprises long α-strips with a large aspect ratio arranged in a "basket weave" or random pattern, which is a microstructural characteristic indicating high fracture toughness. Furthermore, Figure 1-3 The microstructure shown exhibits the absence of continuous α decoration at the β grain boundaries, which the inventors also believe enhances the mechanical properties of the alloy. Example alloy compositions 1, 2, and 3, under solution treatment and aging treatment conditions, exhibit the aforementioned two advantageous microstructural properties.

[0068] It should be understood that the scope of this disclosure is not necessarily limited to alloys containing the elemental contents listed in the examples.

[0069] The following numbered clauses pertain to various non-limiting embodiments according to this disclosure:

[0070] Clause 1. A titanium alloy comprising, by weight percentage based on the total alloy weight: 3.5 to 4.5% aluminum; 1.0% at least 3.0% tin; 1.0 to 3.0% zirconium; 2.0 to 5.5% molybdenum; 2.0 to 4.25% chromium; 0.01 to 0.03% silicon; titanium; and impurities; and wherein the aluminum equivalent of said titanium alloy is 6.0 to 6.9.

[0071] Clause 2. The titanium alloy as described in Clause 1, wherein the molybdenum equivalent value of the titanium alloy is from 4.8 to 10.9.

[0072] Clause 3. The titanium alloy as described in Clause 1, wherein the molybdenum equivalent value of the titanium alloy is from 7.0 to 10.9.

[0073] Clause 4. The titanium alloy as described in any of Clauses 1 to 3, wherein the aluminum equivalent of the titanium alloy is 6.1 to 6.5.

[0074] Clause 5. The titanium alloy described in any one of Clauses 1 to 4, comprising, by weight percentage based on the total alloy weight: 3.5 to 4.5% aluminum; 1.0% at least 3.0% tin; 1.0% to 3.0% zirconium; 2.0% to 5.5% molybdenum; 2.0% to 4.25% chromium; 0.01% to 0.03% silicon; 0% to 0.30% iron; 0% to 0.20% oxygen; 0% to 0.5% nitrogen; 0% to 0.0125% hydrogen; 0% to 0.08% carbon; 0% to 2% vanadium; 0% at least 0.1% germanium; 0% to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities.

[0075] Clause 6. The titanium alloy described in any of Clauses 1 to 5 contains aluminum at a weight percentage of 3.65 to 4.4% based on the total alloy weight.

[0076] Clause 7. The titanium alloy described in any of Clauses 1 to 6 contains 4.2 to 4.4% aluminum by weight based on the total weight of the alloy.

[0077] Clause 8. The titanium alloy described in any of Clauses 1 to 7 contains 0.014 to 0.03% silicon by weight based on the total weight of the alloy.

[0078] Clause 9. The titanium alloy described in any of Clauses 1 to 8 contains 0.02 to 0.03% silicon by weight based on the total weight of the alloy.

[0079] Clause 10. The titanium alloy described in any of Clauses 1 to 9 comprises 3.0 to 4.25% molybdenum and 3.0 to 4.25% chromium by weight percentage based on the total alloy weight.

[0080] Clause 11. A titanium alloy as described in any of Clauses 1 to 10, wherein the titanium alloy exhibits a yield strength of at least 137 ksi, an ultimate tensile strength of at least 148 ksi, and a fracture toughness of at least 85 ksi√(inch).

[0081] Clause 12. A titanium alloy as described in any of Clauses 1 to 11, wherein the titanium alloy exhibits a yield strength of at least 145 ksi, an ultimate tensile strength of at least 155 ksi, and a fracture toughness of at least 89 ksi√(inch).

[0082] Clause 13. The titanium alloy as described in Clause 1, comprising, by weight percentage based on the total alloy weight: 3.65 to 4.4% aluminum; 1.2 to 2.5% tin; 1.2 to 2.2% zirconium; 3.0 to 4.25% molybdenum; 3.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 0 to 2% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities.

[0083] Clause 14. The titanium alloy as described in Clause 13, wherein the molybdenum equivalent value of the titanium alloy is from 4.8 to 10.9.

[0084] Clause 15. The titanium alloy as described in Clause 13, wherein the molybdenum equivalent value of the titanium alloy is from 7.0 to 10.9.

[0085] Clause 16. The titanium alloy described in any of Clauses 13 to 15, wherein the aluminum equivalent of the titanium alloy is 6.1 to 6.5.

[0086] Clause 17. A titanium alloy as described in any of Clauses 13 to 16, wherein the titanium alloy exhibits a yield strength of at least 137 ksi, an ultimate tensile strength of at least 148 ksi, and a fracture toughness of at least 85 ksi√(inch).

[0087] Clause 18. A titanium alloy as described in any of Clauses 13 to 17, wherein the titanium alloy exhibits a yield strength of at least 145 ksi, an ultimate tensile strength of at least 155 ksi, and a fracture toughness of at least 89 ksi√(inch).

[0088] Clause 19. A titanium alloy comprising, by weight percentage based on the total alloy weight: 4.2 to 4.4% aluminum; 1.2 to 1.75% tin; 1.2 to 1.75% zirconium; 4.0 to 4.25% molybdenum; 4.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 1.0 to 2.0% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities; and wherein the aluminum equivalent of said titanium alloy is 6.1 to 6.9.

[0089] Clause 20. A titanium alloy comprising, by weight percentage based on the total alloy weight: 3.65 to 4.4% aluminum; 1.2 to 2.5% tin; 1.2 to 2.2% zirconium; 3.0 to 4.25% molybdenum; 3.0 to 4.25% chromium; 0.02 to 0.03% silicon; 0 to 0.30% iron; 0 to 0.20% oxygen; 0 to 0.5% nitrogen; 0 to 0.0125% hydrogen; 0 to 0.08% carbon; 0 to 2.0% vanadium; 0% at least 0.1% germanium; 0 to 0.1% each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper; titanium; and impurities; wherein the titanium alloy has an aluminum equivalent of 6.1 to 6.5, the titanium alloy has a molybdenum equivalent of 4.8 to 10.9, and the alloy exhibits a yield strength of at least 137 ksi and a strength of at least 148 kJ / kS. Ultimate tensile strength of ksi and fracture toughness of at least 85 ksi√(inches).

[0090] Clause 21. A method for manufacturing a titanium alloy, the method comprising: solution treating the titanium alloy at 800°C to 860°C for 1 to 8 hours; cooling the titanium alloy to ambient temperature; aging the titanium alloy at 480°C to 700°C for 4 to 16 hours; and air cooling the titanium alloy; wherein the titanium alloy has a composition as set forth in any one of Clauses 1 to 20.

[0091] Clause 22. An article comprising a titanium alloy as described in any one of Clauses 1 to 20 or a titanium alloy produced in accordance with Clause 21.

[0092] Clause 23. Articles of manufacture according to Clause 22, wherein said articles of manufacture are selected from the group consisting of: foils, sheets, plates, wires, billets, bars, rods, thick plates, ingots, forgings, castings and powders.

[0093] Various non-limiting embodiments are described and illustrated in this specification to provide an overall understanding of the disclosed invention. It should be understood that the various non-limiting embodiments described and illustrated in this specification are non-limiting and non-exhaustive. Therefore, the invention is not limited to the description of the various non-limiting and non-exhaustive embodiments disclosed in this specification. Rather, the invention seeking a patent sequence is defined only by the claims. Features and characteristics illustrated and / or described in conjunction with the various non-limiting embodiments may be combined with features and characteristics of other non-limiting embodiments. Such modifications and variations are intended to be included within the scope of this specification. Consequently, the claims may be amended or supplemented to state any feature or characteristic expressly or inherently described in this specification or otherwise expressly or inherently supported by this specification. Furthermore, the applicant reserves the right to amend the claims to expressly waive any rights to features or characteristics that may be present in the prior art. The various non-limiting embodiments disclosed and described in this specification may include, consist of, or substantially consist of features and characteristics as described herein differently.

[0094] Any patent, publication, or other disclosure incorporated herein by reference, in whole or in part, is incorporated only to the extent that the incorporated material does not conflict with the existing definitions, statements, or other disclosures set forth in this disclosure. Thus, and to the extent necessary, the disclosure set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or part thereof, that is alleged to conflict with existing definitions, statements, or other disclosures set forth herein by reference is incorporated only to the extent that the incorporated material does not conflict with existing disclosures.

[0095] In this specification, unless otherwise stated, all numerical parameters should be understood to begin with and be modified by the term "about" in all cases, whereby the numerical parameters have the inherent variability of the underlying measurement techniques used to determine the parameter values. To a minimum, and without attempting to limit the application of the equivalence principle to the scope of the claims, each numerical parameter described in this specification should be interpreted at least according to the number of significant digits reported and by applying general rounding techniques.

[0096] Furthermore, any numerical range set forth in this specification is intended to include all subranges with the same numerical precision that are incorporated within the set forth range. For example, the range “1 to 10” is intended to include all subranges between (and including) the set forth minimum value of 1 and the set forth maximum value of 10, that is, a minimum value equal to or greater than 1 and a maximum value equal to or less than 10, such as 2.4 to 7.6. Any maximum numerical limit set forth in this specification is intended to include all lower numerical limits incorporated herein, and any minimum numerical limit set forth in this specification is intended to include all higher numerical limits incorporated herein. Therefore, the applicant reserves the right to amend this specification (including the claims) to expressly describe any subranges incorporated within the scope expressly described herein. It is intended that all such ranges be described in this specification such that any amendments used to expressly describe any such subranges will comply with the requirements of 35 USC §§ 112 and 132(a).

[0097] Unless otherwise stated, the grammatical articles “one,” “a,” “an,” and “the” used in this specification are intended to include “at least one” or “one or more.” Therefore, grammatical articles are used in this specification to refer to one or more of the grammatical objects of the article (i.e., to refer to “at least one”). By way of example only, “component” means one or more components, and therefore it is possible that more than one component is contemplated, and that said more than one component may be employed or used in embodiments of the described examples. Furthermore, unless the context requires otherwise, the use of singular nouns includes plural nouns, and the use of plural nouns includes singular nouns.

[0098] Those skilled in the art will recognize that, for clarity of concept, the alloys and methods described herein, along with their accompanying hollowing out, are used as examples, and various modifications are contemplated. Therefore, as used herein, the specific examples / implementations illustrated and the accompanying discussion are intended to represent their more general categories. In general, the use of any specific paradigm is intended to indicate the category of the paradigm and should not be considered limiting. While this disclosure provides descriptions of various specific embodiments for the purpose of illustrating various aspects of this disclosure and / or its potential applications, it should be understood that variations and modifications will occur to those skilled in the art. Therefore, one or more of the inventions described herein should be understood to be at least as broad as claimed, and not more narrowly defined than the specific examples and illustrative embodiments provided herein.

Claims

1. A titanium alloy comprising, by weight percentage based on the total alloy weight: Aluminum up to 4.5; Tin content of at least 3.0; Zirconium up to 3.0; Molybdenum up to 5.5; Chromium up to 4.25; Silicon up to 0.03; titanium; as well as Impurities; The titanium alloy has an aluminum equivalent of 6.0 to 6.

9.

2. The titanium alloy according to claim 1, wherein the molybdenum equivalent value of the titanium alloy is 4.8 to 10.

9.

3. The titanium alloy according to claim 1, wherein the molybdenum equivalent value of the titanium alloy is 7.0 to 10.

9.

4. The titanium alloy according to claim 1, wherein the aluminum equivalent value of the titanium alloy is 6.1 to 6.

5.

5. The titanium alloy of claim 1, comprising, by weight percentage based on the total alloy weight: Aluminum up to 4.5; Tin content of at least 3.0; Zirconium up to 3.0; Molybdenum up to 5.5; Chromium up to 4.25; Silicon up to 0.03; Iron content between 0 and 0.30; Oxygen levels of 0 to 0.20; Nitrogen content of 0 to 0.5; Hydrogen concentrations ranging from 0 to 0.0125; Carbon from 0 to 0.08; Vanadium from 0 to 2; Germanium of at least 0.1; Each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper, in amounts from 0 to 0.1; Titanium; and Impurities.

6. The titanium alloy of claim 1, wherein it contains 3.65 to 4.4% aluminum by weight percentage based on the total alloy weight.

7. The titanium alloy of claim 1, wherein it contains 4.2 to 4.4% aluminum by weight percentage based on the total alloy weight.

8. The titanium alloy of claim 1, wherein it contains 0.014 to 0.03% silicon by weight percentage based on the total alloy weight.

9. The titanium alloy of claim 1, wherein it contains 0.02 to 0.03% silicon by weight percentage based on the total alloy weight.

10. The titanium alloy of claim 1, comprising 3.0 to 4.25% molybdenum and 3.0 to 4.25% chromium by weight percentage based on the total alloy weight.

11. The titanium alloy of claim 1, wherein the titanium alloy exhibits a yield strength of at least 137 ksi, an ultimate tensile strength of at least 148 ksi, and a fracture toughness of at least 85 ksi√(inch).

12. The titanium alloy of claim 1, wherein the titanium alloy exhibits a yield strength of at least 145 ksi, an ultimate tensile strength of at least 155 ksi, and a fracture toughness of at least 89 ksi√(inch).

13. The titanium alloy of claim 1, comprising, by weight percentage based on the total alloy weight: Aluminum up to 4.4; Tin up to 2.5; Zirconium up to 2.2; Molybdenum up to 4.25; Chromium up to 4.25; Silicon up to 0.03; Iron content between 0 and 0.30; Oxygen levels of 0 to 0.20; Nitrogen content of 0 to 0.5; Hydrogen concentrations of 0 to 0.0125; Carbon content of 0 to 0.08; Vanadium from 0 to 2.0; Germanium of at least 0.1; Each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper, in amounts from 0 to 0.1; Titanium; and Impurities.

14. The titanium alloy of claim 13, wherein the molybdenum equivalent value of the titanium alloy is from 4.8 to 10.

9.

15. The titanium alloy of claim 13, wherein the molybdenum equivalent value of the titanium alloy is 7.0 to 10.

9.

16. The titanium alloy of claim 13, wherein the aluminum equivalent of the titanium alloy is 6.1 to 6.

5.

17. The titanium alloy of claim 13, wherein the titanium alloy exhibits a yield strength of at least 137 ksi, an ultimate tensile strength of at least 148 ksi, and a fracture toughness of at least 85 ksi√(inch).

18. The titanium alloy of claim 13, wherein the titanium alloy exhibits a yield strength of at least 145 ksi, an ultimate tensile strength of at least 155 ksi, and a fracture toughness of at least 89 ksi√(inch).

19. A method for manufacturing a titanium alloy, the method comprising: The titanium alloy is solution treated at 800°C to 860°C for 1 to 8 hours. Cool the titanium alloy to ambient temperature; The titanium alloy is aged at 480°C to 700°C for 4 to 16 hours. as well as The titanium alloy was air-cooled; The titanium alloy described herein has the composition as described in claim 1.

20. A titanium alloy comprising, by weight percentage based on the total alloy weight: Aluminum up to 4.4; Tin up to 1.75; Zirconium up to 1.75; Molybdenum up to 4.25; Chromium up to 4.25; Silicon up to 0.03; Iron content between 0 and 0.30; Oxygen levels of 0 to 0.20; Nitrogen content of 0 to 0.5; Hydrogen concentrations of 0 to 0.0125; Carbon content of 0 to 0.08; Vanadium up to 2.0; Germanium of at least 0.1; Each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper, in amounts from 0 to 0.1; titanium; as well as Impurities; The aluminum equivalent of the titanium alloy is 6.1 to 6.

9.

21. A titanium alloy comprising, by weight percentage based on the total alloy weight: Aluminum up to 4.4; Tin up to 2.5; Zirconium up to 2.2; Molybdenum up to 4.25; Chromium up to 4.25; Silicon up to 0.03; Iron content between 0 and 0.30; Oxygen levels of 0 to 0.20; Nitrogen content of 0 to 0.5; Hydrogen concentrations of 0 to 0.0125; Carbon content of 0 to 0.08; Vanadium from 0 to 2; Germanium of at least 0.1; Each of niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper, in amounts from 0 to 0.1; titanium; as well as Impurities; The titanium alloy has an aluminum equivalent of 6.1 to 6.5, and a molybdenum equivalent of 4.8 to 10.9; and The titanium alloy described therein exhibits a yield strength of at least 137 ksi, an ultimate tensile strength of at least 148 ksi, and a fracture toughness of at least 85 ksi√(inch).

22. An article comprising the titanium alloy according to claim 1.

23. The article of claim 22, wherein the article is selected from the group consisting of: foil, sheet, plate, wire, billet, rod, bar, thick plate, ingot, forging, casting and powder.

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