High Temperature Titanium Alloy

Abstract

A titanium alloy having improved creep resistance and / or tensile strength at elevated temperatures is provided. The titanium alloy includes, in weight percent based on the total weight of the alloy, 5.1-6.5 aluminum, 1.9-3.2 tin, 1.8-3.1 zirconium, 3.3-5.5 molybdenum, 3.3-5.2 chromium, 0.08-0.15 oxygen, 0.03-0.20 silicon, 0-0.30 iron, titanium, and impurities. A non-limiting embodiment of the titanium alloy includes the intentional addition of silicon, along with certain other alloying additions, to achieve an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4-12.8, which have been observed to improve tensile strength at elevated temperatures.

Description

[Technical Field]

[0001] The present disclosure relates to high temperature titanium alloys. [Background technology]

[0002] Titanium alloys typically exhibit high strength-to-weight ratios, are corrosion-resistant, and resist creep at moderately high temperatures. For example, Ti-5Al-4Mo-4Cr-2Sn-2Zr alloy (also designated "Ti-17 alloy" with a composition specified in UNS R58650) is a commercially available alloy widely used in jet engine applications requiring a combination of high strength, fatigue resistance, and toughness at operating temperatures up to 800°F (approximately 427°C). Other examples of titanium alloys used in high-temperature applications include Ti-6Al-2Sn-4Zr-2Mo alloy (with a composition specified in UNS R54620) and Ti-3Al-8V-6Cr-4Mo-4Zr alloy (also designated "Beta-C" with a composition specified in UNS R58640). However, these alloys have limited creep resistance and / or tensile strength at high temperatures. A need has arisen for titanium alloys with improved creep resistance and / or tensile strength at high temperatures. Summary of the Invention

[0003] According to one non-limiting embodiment of the present disclosure, the titanium alloy comprises, in weight percent based on the total weight of the alloy, 5.5-6.5 aluminum, 1.9-2.9 tin, 1.8-3.0 zirconium, 4.5-5.5 molybdenum, 4.2-5.2 chromium, 0.08-0.15 oxygen, 0.03-0.20 silicon, 0-0.30 iron, titanium, and impurities.

[0004] According to yet another non-limiting embodiment of the present disclosure, the titanium alloy includes, in weight percent based on the total weight of the alloy, 5.1-6.1 aluminum, 2.2-3.2 tin, 1.8-3.1 zirconium, 3.3-4.3 molybdenum, 3.3-4.3 chromium, 0.08-0.15 oxygen, 0.03-0.20 silicon, 0-0.30 iron, titanium, and impurities.

[0005] The features and advantages of the alloys, articles and methods described herein may be better understood with reference to the accompanying drawings. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a plot illustrating a non-limiting embodiment of a method of processing a non-limiting embodiment of a titanium alloy according to the present disclosure. [Figure 2] Scanning electron microscope image (backscattered electron mode) of the processed titanium alloy in Figure 1, where "a" identifies primary α, "b" identifies grain boundary α, "c" identifies α lath, "d" identifies secondary α, and "e" identifies silicide. [Figure 3] Scanning electron microscope images (backscattered electron mode) of comparative solution-treated and aged titanium alloys, where "a" identifies primary α, "b" identifies boundary α, "c" identifies α lath, and "d" identifies secondary α. [Figure 4] FIG. 1 is a plot of ultimate tensile strength versus temperature for non-limiting embodiments of titanium alloys according to the present disclosure, comparing their properties with comparative and conventional titanium alloys. [Figure 5] FIG. 1 is a plot of yield strength versus temperature for non-limiting embodiments of titanium alloys according to the present disclosure, comparing their properties with comparative and conventional titanium alloys. [Figure 6] 1 is a scanning electron microscope image (backscattered electron mode) of a non-limiting embodiment of a titanium alloy according to the present disclosure, where "a" identifies grain boundary α, "b" identifies α lath, "c" identifies secondary α, and "d" identifies silicide. DETAILED DESCRIPTION OF THE INVENTION

[0007] The reader will appreciate the above details, as well as others, upon consideration of the following detailed description of certain non-limiting embodiments according to the present disclosure.

[0008] In the non-limiting embodiments herein, other than in the examples or unless otherwise specified, all numbers expressing quantities or properties are to be understood as being modified in each instance by the term "about." Accordingly, unless specifically indicated to the contrary, any numerical parameters set forth in the following specification are approximations that may vary depending upon the desired properties sought to be obtained in the materials and methods according to the present disclosure. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed at least in light of the number of reported significant digits and by applying ordinary rounding techniques. All ranges set forth herein include the recited endpoints unless otherwise stated.

[0009] Any patent, publication, or other disclosure that is incorporated herein by reference in whole or in part is incorporated herein to the extent that the incorporated content does not contradict existing definitions, descriptions, or other disclosure content set forth in this disclosure. Therefore, to the extent necessary, the disclosure set forth herein supersedes any conflicting content incorporated herein by reference. Any content, or portion thereof, that is incorporated herein by reference but that contradicts existing definitions, descriptions, or other disclosure content set forth herein is incorporated to the extent that a conflict does not arise between the incorporated content and the existing disclosure content.

[0010] Articles and components in high temperature environments can suffer from creep. As used herein, "high temperature" refers to temperatures above about 100°F (about 37.8°C). Creep is the strain that occurs under stress over time. Creep that occurs at a decreasing strain rate is referred to as primary creep, creep that occurs at a minimum and near-constant strain rate is referred to as secondary (steady-state) creep, and creep that occurs at an accelerating strain rate is referred to as tertiary creep. Creep strength is the stress that produces a given creep strain in a creep test at a given time in a specific, constant environment.

[0011] The creep resistance behavior of titanium and titanium alloys at elevated temperatures and under sustained loads depends primarily on microstructural features. Titanium exists in two allotropes: the beta ("β") phase, which has a body-centered cubic ("bcc") crystal structure, and the alpha ("α") phase, which has a hexagonal close-packed ("hcp") crystal structure. Generally, beta titanium alloys have poor high-temperature creep strength. This poor high-temperature creep strength is the result of the significant enrichment of the beta phase that these alloys exhibit at high temperatures, e.g., 500°C. The beta phase, due to its body-centered cubic structure, does not adequately resist creep and defines multiple deformation mechanisms. These shortcomings have limited the use of beta titanium alloys.

[0012] One group of titanium alloys widely used for various applications is α / β titanium alloys. In α / β titanium alloys, the distribution and size of primary α particles can directly affect creep resistance. Various published studies on silicon-containing α / β titanium alloys have shown that silicide precipitation at grain boundaries can further improve creep resistance but at the expense of room-temperature tensile ductility. The decrease in room-temperature tensile ductility caused by the addition of silicon limits the amount of silicon that can be added, typically to 0.2% (by weight).

[0013] The present disclosure is directed, in part, to alloys that address certain limitations of conventional titanium alloys. Figure 1 illustrates a non-limiting embodiment of a method for processing a non-limiting embodiment of a titanium alloy according to the present disclosure. An embodiment of a titanium alloy according to the present disclosure includes, in weight percent based on the total weight of the alloy, 5.5-6.5 aluminum, 1.9-2.9 tin, 1.8-3.0 zirconium, 4.5-5.5 molybdenum, 4.2-5.2 chromium, 0.08-0.15 oxygen, 0.03-0.20 silicon, 0-0.30 iron, titanium, and impurities. Another embodiment of a titanium alloy according to the present disclosure contains, in weight percentages based on the total weight of the alloy, 5.5-6.5 aluminum, 2.2-2.6 tin, 2.0-2.8 zirconium, 4.8-5.2 molybdenum, 4.5-4.9 chromium, 0.08-0.13 oxygen, 0.03-0.11 silicon, 0-0.25 iron, titanium, and impurities. Yet another embodiment of a titanium alloy according to the present disclosure contains, in weight percentages based on the total weight of the alloy, 5.9-6.0 aluminum, 2.3-2.5 tin, 2.3-2.6 zirconium, 4.9-5.1 molybdenum, 4.5-4.8 chromium, 0.08-0.13 oxygen, 0.03-0.10 silicon, up to 0.07 iron, titanium, and impurities. In non-limiting embodiments of alloys according to the present disclosure, the elements and impurities incidentally present in the alloy composition may include or consist essentially of one or more of nitrogen, carbon, hydrogen, niobium, tungsten, vanadium, tantalum, manganese, nickel, hafnium, gallium, antimony, cobalt, and copper. Specific non-limiting embodiments of titanium alloys according to the present disclosure may include, in weight percentages based on the total weight of the alloy, 0-0.05 nitrogen, 0-0.05 carbon, 0-0.015 hydrogen, and 0 up to 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper.

[0014] In certain non-limiting embodiments of the present titanium alloy, the titanium alloy includes the intentional addition of silicon, in conjunction with certain other alloying additions, to achieve an equivalent aluminum value of 6.9 to 9.5 and an equivalent molybdenum value of 7.4 to 12.8, at which the inventors have observed improved tensile strength at elevated temperatures. As used herein, "equivalent aluminum value" or "aluminum equivalent" (Al eq ) can be determined as follows (where, as indicated, all element concentrations are in weight percentages): Al eq =Al (重量%) +(1 / 6)×Zr (重量%) +(1 / 3)×Sn (重量%) +10×O (重量%) As used herein, "molybdenum equivalent" or "molybdenum equivalent" (Mo eq ) can be determined as follows (where, as indicated, all element concentrations are in weight percentages): Mo eq =Mo (重量%) +(1 / 5)×Ta (重量%) +(1 / 3.6)×Nb (重量%) +(1 / 2.5)×W (重量%) +(1 / 1.5)×V (重量%) +1.25×Cr (重量%) +1.25×Ni (重量%) +1.7×Mn (重量%) +1.7×Co (重量%) +2.5×Fe (重量%) .

[0015] While it is recognized that the mechanical properties of titanium alloys are generally affected by the size of the specimen being tested, in one non-limiting embodiment according to the present disclosure, the titanium alloy exhibits an ultimate tensile strength of at least 160 ksi and at least 10% elongation at 316°C, with an equivalent aluminum value of at least 6.9, or in certain embodiments, in the range of 8.0-9.5, and an equivalent molybdenum value of 9.0-12.8. In another non-limiting embodiment according to the present disclosure, the titanium alloy exhibits a yield strength of at least 150 ksi and at least 10% elongation at 316°C, with an equivalent aluminum value of at least 6.9, or in certain embodiments, in the range of 8.0-9.5, and an equivalent molybdenum value of 8.0-12.8. In yet another non-limiting embodiment according to the present disclosure, the titanium alloy exhibits a yield strength of at least 6.9, or in certain embodiments, in the range of 6.9-9.5, and an equivalent molybdenum value of 7.4-12.8, and exhibits a time to 0.2% creep strain of at least 20 hours at 427°C under a load of 60 ksi. In yet another non-limiting embodiment, the titanium alloy according to the present disclosure has a hardness of at least 6 0.9 or in certain embodiments in the range of 8.0 to 9.5, an aluminum equivalent value of 7.4 to 10.4, and exhibiting a time to 0.2% creep strain of 86 hours or more at 427°C under a load of 60 ksi.

[0016] Table 1 shows the elemental compositions of non-limiting embodiments of titanium alloys according to the present disclosure ("Experimental Titanium Alloy No. 1" and "Experimental Titanium Alloy No. 2"), comparative titanium alloy embodiments containing no intentional silicon additions, and certain conventional titanium alloy embodiments. eq and Mo eq Without wishing to be bound by theory, it is believed that the silicon content of Experimental Titanium Alloy No. 1 and Experimental Titanium Alloy No. 2 listed in Table 1 may promote the precipitation of one or more silicide phases. [Table 1]

[0017] Manufacture 9-inch diameter electrodes weighing approximately 400 lb to 800 lb each (product Plasma arc melting (PAM) heat for many of the comparative titanium alloys and experimental titanium alloy No. 1 listed in Table 1 was generated using a plasma arc furnace. Electrodes were remelted in a vacuum arc remelting (VAR) furnace to produce 10-inch diameter ingots. Each ingot was converted into a 3-inch diameter billet using a hot working press. After the β-forging step to a 7-inch diameter, the α + β pre-strain forging step to a 5-inch diameter, and the β-finish forging step to a 3-inch diameter, the ends of each billet were cropped to remove suck-ins and end cracks, and the billets were cut into multiple pieces. The top of each billet and the bottom of the bottommost 7-inch diameter billet were sampled for chemistry and β transus. Based on the results of the intermediate billet chemistry, 2-inch long specimens were cut from the billets and "pancake"-forged in a press. The pancake specimens were heat treated using the following heat treatment profile corresponding to the solution-treated and aging conditions: solution-treating the titanium alloy at 800°C for 4 hours, water-quenching the titanium alloy to ambient temperature, aging the titanium alloy at 635°C for 8 hours, and air-cooling the titanium alloy.

[0018] As used herein, the term "solution treating and aging (STA)" refers to a heat treatment process applied to a titanium alloy that involves solution treating the titanium alloy at a solution treating temperature below the β transus temperature of the titanium alloy. In a non-limiting embodiment, the solution treating temperature is a temperature in the range of about 800°C to about 860°C. The solution treated alloy is then aged by heating the alloy for a period of time to an aging temperature range below the β transus temperature and below the solution treating temperature of the titanium alloy. As used herein with reference to a temperature, temperature range, or minimum temperature, terms such as "heated to" or "heating to" mean heating the alloy until at least a desired portion of the alloy has a temperature at least equal to or included within the reference temperature range throughout that subrange. In a non-limiting embodiment, the solution treating time is in the range of about 30 minutes to about 4 hours. In certain non-limiting embodiments, the solution treatment time may be less than 30 minutes or more than 4 hours, and is generally recognized as depending on the cross-section and size of the titanium alloy. Upon completion of the solution treatment, the titanium alloy is cooled to ambient temperature at a rate that depends on the thickness of the cross-section of the titanium alloy.

[0019] The solution-treated titanium alloy is then aged at an aging temperature, also referred to herein as the "age-hardening temperature," in the α + β phase field below the β transus temperature of the titanium alloy. In a non-limiting embodiment, the aging temperature is a temperature in the range of about 620°C to about 650°C. In certain non-limiting embodiments, the aging time may range from about 30 minutes to about 8 hours. It is recognized that in certain non-limiting embodiments, the aging time may be less than 30 minutes or greater than 8 hours, and will generally depend on the cross section and size of the titanium alloy product form. The general techniques used in STA processing of titanium alloys are known to those skilled in the art and will not be further described herein.

[0020] Test blanks for room and elevated temperature tensile tests, creep tests, fracture toughness, and microstructural analysis were cut from the STA processed pancake specimens. To ensure accurate correlation between chemical and mechanical properties, a final chemical analysis was performed on the fracture toughness coupons after testing.

[0021] Examination of the final 3-inch diameter billet revealed a uniform, lamellar alpha / beta microstructure. Referring to Figure 2 (showing Experimental Titanium Alloy No. 1 listed in Table 1) and Figure 3 (showing Comparative Titanium Alloys listed in Table 1), the forged and STA heat treated Panket Metallography on samples removed from the brake specimens revealed a fine network of Widmanstatten α with some primary and grain boundary α. Notably, experimental titanium alloy No. 1 contained silicide precipitates (see Figure 2, where silicide precipitates are identified as "e"), while the comparative titanium alloys listed in Table 1 did not contain silicide precipitates (see Figure 3).

[0022] Referring to Figures 4-5, the mechanical properties of experimental titanium alloy No. 1 (labeled "08BA" in Figures 4-5) listed in Table 1 were measured and compared with those of a comparative titanium alloy (labeled "07BA" in Figures 4-5) listed in Table 1 and a conventional Ti17 alloy (having the composition specified in UNS-R58650, labeled "B4E89" in Figures 4-5). Tensile tests were conducted in accordance with ASTM International Standard E8 / E8M-09 ("Standard Test Methods for Tension Testing of Metallic Materials," ASTM International, 2009). As shown by the experimental results in Table 2, experimental titanium alloy No. 1 exhibited significantly greater ultimate tensile strength, yield strength, and ductility (reported as % elongation) at 316°C compared to comparative titanium alloys and certain conventional titanium alloys that did not contain intentional silicon additions (e.g., Ti64 alloy and Ti17 alloy), as well as compared to certain conventional titanium alloys that contained intentional silicon additions (e.g., Ti834 alloy and Ti6242Si alloy). [Table 2]

[0023] High temperature tensile test results and creep test results at 427°C for Experimental Titanium Alloy No. 1 (with intentional silicon addition) and Experimental Titanium Alloy No. 2 (with intentional silicon addition) listed in Table 1 were compared to the results for the Comparative Titanium Alloys (without intentional silicon addition) and certain conventional titanium alloys listed in Table 1. The data are shown in Table 3. Experimental Titanium Alloy No. 1, for example, exhibited approximately a 25% increase in UTS and approximately a 77% increase in creep life at 427°C compared to the Comparative Titanium Alloy. [Table 3]

[0024] Certain alternative titanium alloy embodiments are now described. According to one non-limiting aspect of the present disclosure, the titanium alloy includes, in weight percent based on the total weight of the alloy, 5.1-6.1 aluminum, 2.2-3.2 tin, 1.8-3.1 zirconium, 3.3-4.3 molybdenum, 3.3-4.3 chromium, 0.08-0.15 oxygen, 0.03-0.20 silicon, 0-0.30 iron, titanium, and impurities. Another embodiment of a titanium alloy according to the present disclosure contains, in weight percentages based on the total weight of the alloy, 5.1-6.1 aluminum, 2.2-3.2 tin, 2.1-3.1 zirconium, 3.3-4.3 molybdenum, 3.3-4.3 chromium, 0.08-0.15 oxygen, 0.03-0.11 silicon, 0-0.30 iron, titanium, and impurities. A further embodiment of a titanium alloy according to the present disclosure contains, in weight percentages based on the total weight of the alloy, 5.6-5.8 aluminum, 2.5-2.7 tin, 2.6-2.7 zirconium, 3.8-4.0 molybdenum, 3.7-3.8 chromium, 0.08-0.14 oxygen, 0.03-0.05 silicon, and up to 0.06 iron, titanium, and impurities. In non-limiting embodiments of titanium alloys according to the present disclosure, incidental elements and impurities in the alloy composition may include or consist essentially of one or more of nitrogen, carbon, hydrogen, niobium, tungsten, vanadium, tantalum, manganese, nickel, hafnium, gallium, antimony, cobalt, and copper. In particular embodiments of titanium alloys according to the present disclosure, 0-0.05 nitrogen, 0-0.05 carbon, 0-0.015 hydrogen, and 0 up to 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper may be present in the titanium alloys disclosed herein.

[0025] Similar to the titanium alloys illustrated in and described in conjunction with Figures 1-3, the alternative titanium alloys have intentionally added silicon. However, the alternative titanium alloy embodiments have reduced chromium content compared to the experimental titanium alloys described in connection with Figures 1-3. Table 1 lists the composition of a non-limiting embodiment of an alternative titanium alloy with reduced chromium content and intentionally added silicon ("Experimental Titanium Alloy No. 2").

[0026] In certain non-limiting embodiments of titanium alloys according to the present disclosure, the titanium alloys may be added with certain other alloying additions to achieve aluminum equivalents of at least 6.9 and molybdenum equivalents of 7.4 to 12.8, which have been observed to improve tensile strength at elevated temperatures. In certain non-limiting embodiments of the present disclosure, the titanium alloy exhibits an ultimate tensile strength of at least 150 ksi at 316°C, with an equivalent aluminum value of at least 6.9, or in certain embodiments, in the range of 6.9-9.5, and an equivalent molybdenum value of 7.4-12.8. In other non-limiting embodiments of the present disclosure, the titanium alloy exhibits a yield strength of at least 130 ksi at 316°C, with an equivalent aluminum value of at least 6.9, or in certain embodiments, in the range of 8.0-9.5, and an equivalent molybdenum value of 7.4-12.8. In yet other non-limiting embodiments, the titanium alloy exhibits a yield strength of at least 6.9, or in certain embodiments, in the range of 8.0-9.5, and an equivalent aluminum value of at least 6.9, or in certain embodiments, in the range of 8.0-9.5, and an equivalent molybdenum value of 7.4-12.8, and exhibits a time to 0.2% creep strain of at least 86 hours at 427°C under a load of 60 ksi.

[0027] High temperature tensile test results and creep test results for Experimental Titanium Alloy No. 2 in Table 1 at 800°F (427°C) are listed in Table 3. Prior to testing, the alloy was subjected to the heat treatments identified in the embodiments described above in connection with FIGS. 1-3, i.e., solution treating the titanium alloy at 800°C for 4 hours, water quenching the titanium alloy to ambient temperature, aging the titanium alloy at 635°C for 8 hours, and air cooling the titanium alloy. Referring to FIG. 6, the metallography of the STA heat-treated Experimental Alloy No. 2 revealed a silicide precipitate (one precipitate identified as "d"). Without being bound by theory, it is believed that the silicon content of Experimental Titanium Alloy No. 2 listed in Table 1 may promote the precipitation of this silicide phase.

[0028] Certain embodiments of alloys produced in accordance with the present disclosure and articles made from those alloys may be advantageously applied to aviation parts and components, such as, for example, jet engine turbine disks and turbofan blades. One skilled in the art will be able to produce the aforementioned devices, parts, and other products from alloys according to the present disclosure without further explanation being provided herein. The above-described examples of potential uses for alloys according to the present disclosure are provided by way of example only and are not intended to be exhaustive of all applications to which the product forms of the alloys of the present invention may be applied. One skilled in the art will be able to readily identify additional uses for the alloys described herein upon reading this disclosure.

[0029] Various non-exhaustive, non-limiting embodiments of the novel alloys according to the present disclosure may be useful alone or in combination with one or more other embodiments described herein. Without limiting the foregoing, in a first non-limiting embodiment of the present disclosure, a titanium alloy includes, in weight percent based on the total weight of the alloy, 5.5-6.5 aluminum, 1.9-2.9 tin, 1.8-3.0 zirconium, 4.5-5.5 molybdenum, 4.2-5.2 chromium, 0.08-0.15 oxygen, 0.03-0.20 silicon, 0-0.30 iron, titanium, and impurities.

[0030] According to a second non-limiting aspect of the present disclosure that may be used in combination with the first aspect, the titanium alloy includes, in weight percentages based on the total weight of the alloy, 5.5-6.5 aluminum, 2.2-2.6 tin, 2.0-2.8 zirconium, 4.8-5.2 molybdenum, 4.5-4.9 chromium, 0.08-0.13 oxygen, 0.03-0.11 silicon, 0-0.25 iron, titanium, and impurities.

[0031] According to a third non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy includes, in weight percentages based on the total weight of the alloy, 5.9-6.0 aluminum, 2.3-2.5 tin, 2.3-2.6 zirconium, 4.9-5.1 molybdenum, 4.5-4.8 chromium, 0.08-0.13 oxygen, 0.03-0.10 silicon, and up to 0.07 iron, titanium, and impurities.

[0032] According to a fourth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy further comprises, in weight percentages based on the total weight of the alloy, 0 to 0.05 nitrogen, 0 to 0.05 carbon, 0 to 0.015 hydrogen, and 0 to a maximum of 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper.

[0033] According to a fifth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum content of at least 6.9 and an equivalent molybdenum content of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 160 ksi at 316°C.

[0034] According to a sixth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum content of at least 6.9 and an equivalent molybdenum content of 7.4 to 12.8, and exhibits a yield strength of at least 140 ksi at 316°C.

[0035] According to a seventh non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of at least 20 hours at 427°C under a load of 60 ksi.

[0036] According to an eighth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum content of 8.0 to 9.5 and an equivalent molybdenum content of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 160 ksi at 316°C.

[0037] According to a ninth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum content of 8.0 to 9.5 and an equivalent molybdenum content of 7.4 to 12.8, and exhibits a yield strength of at least 140 ksi at 316°C.

[0038] According to a tenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an aluminum equivalent of 8.0 to 9.5 and a molybdenum equivalent of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of at least 20 hours at 427°C under a load of 60 ksi.

[0039] According to an eleventh non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the embodiments mentioned above, the titanium alloy is made by a process including: solution treating the titanium alloy at 800°C to 860°C for 4 hours; cooling the titanium alloy to ambient temperature at a rate dependent on a cross-sectional thickness of the titanium alloy; aging the titanium alloy at 620°C to 650°C for 8 hours; and air cooling the titanium alloy.

[0040] According to a twelfth non-limiting aspect of the present disclosure, the present disclosure also provides a titanium alloy including, in weight percent based on the total weight of the alloy, 5.1 to 6.1 aluminum, 2.2 to 3.2 tin, 1.8 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, 0.03 to 0.20 silicon, 0 to 0.30 iron, titanium, and impurities.

[0041] According to a thirteenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy includes, in weight percentages based on the total weight of the alloy, 5.1 to 6.1 aluminum, 2.2 to 3.2 tin, 2.1 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, 0.03 to 0.11 silicon, 0 to 0.30 iron, titanium, and impurities.

[0042] According to a fourteenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy includes, in weight percentages based on the total weight of the alloy, 5.6-5.8 aluminum, 2.5-2.7 tin, 2.6-2.7 zirconium, 3.8-4.0 molybdenum, 3.7-3.8 chromium, 0.08-0.14 oxygen, 0.03-0.05 silicon, and up to 0.06 iron, titanium, and impurities.

[0043] According to a fifteenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy further comprises, in weight percentages based on the total weight of the alloy, 0 to 0.05 nitrogen, 0 to 0.05 carbon, 0 to 0.015 hydrogen, and 0 to a maximum of 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper.

[0044] According to a sixteenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 150 ksi at 316°C.

[0045] According to a seventeenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum content of at least 6.9 and an equivalent molybdenum content of 7.4 to 12.8, and exhibits a yield strength of at least 130 ksi at 316°C.

[0046] According to an eighteenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of 86 hours or greater at 427°C under a load of 60 ksi.

[0047] According to a nineteenth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum content of 6.9 to 9.5 and an equivalent molybdenum content of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 150 ksi at 316°C.

[0048] According to a twentieth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an equivalent aluminum content of 8.0 to 9.5 and an equivalent molybdenum content of 7.4 to 12.8, and exhibits a yield strength of at least 130 ksi at 316°C.

[0049] According to a twenty-first non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy has an aluminum equivalent of 8.0 to 9.5 and a molybdenum equivalent of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of 86 hours or greater at 427°C under a load of 60 ksi.

[0050] According to a twenty-second non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the embodiments mentioned above, the titanium alloy is made by a process including solution treating the titanium alloy at 800°C to 860°C for 4 hours, water quenching the titanium alloy to ambient temperature, aging the titanium alloy at 620°C to 650°C for 8 hours, and air cooling the titanium alloy.

[0051] According to a twenty-third non-limiting aspect of the present disclosure, the present disclosure also provides a method of making an alloy, comprising solution treating a titanium alloy at 800°C to 860°C for four hours, wherein the titanium alloy comprises 5.5 to 6.5 aluminum, 1.9 to 2.9 tin, 1.8 to 3.0 zirconium, 4.5 to 5.5 molybdenum, 4.2 to 5.2 chromium, 0.08 to 0.15 oxygen, 0.03 to 0.20 silicon, 0 to 0.30 iron, titanium, and impurities; cooling the titanium alloy to ambient temperature at a rate dependent on a cross-sectional thickness of the titanium alloy; aging the titanium alloy at 620°C to 650°C for eight hours; and air cooling the titanium alloy.

[0052] According to a twenty-fourth non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy further comprises, in weight percentages based on the total weight of the alloy, 0 to 0.05 nitrogen, 0 to 0.05 carbon, 0 to 0.015 hydrogen, and 0 to a maximum of 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper.

[0053] According to a twenty-fifth non-limiting aspect of the present disclosure, the present disclosure also provides a method of making an alloy, comprising solution treating a titanium alloy at 800°C to 860°C for four hours, wherein the titanium alloy comprises 5.1 to 6.1 aluminum, 2.2 to 3.2 tin, 1.8 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, 0.03 to 0.20 silicon, 0 to 0.30 iron, titanium, and impurities; cooling the titanium alloy to ambient temperature at a rate dependent on a cross-sectional thickness of the titanium alloy; aging the titanium alloy at 620°C to 650°C for eight hours; and air cooling the titanium alloy.

[0054] According to a 26th non-limiting embodiment of the present disclosure, which may be used in combination with each or any of the above-mentioned embodiments, the titanium alloy further comprises, in weight percentages based on the total weight of the alloy, 0 to 0.05 nitrogen, 0 to 0.05 carbon, 0 to 0.015 hydrogen, and 0 to a maximum of 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper.

[0055] It is understood that this specification describes those aspects of the present invention that are pertinent to a clear understanding of the invention. Certain aspects that would be apparent to those skilled in the art and that do not facilitate a better understanding of the invention have not been presented in order to concise the specification. While necessarily a limited number of embodiments of the present invention are described herein, those skilled in the art will recognize that many modifications and variations of the present invention may be made in light of the foregoing description. All such modifications and variations of the present invention are intended to be encompassed by the foregoing description and the following claims. [Mode of the invention] [1] A titanium alloy comprising, in weight percent based on the total weight of the alloy: 5.5~6.5 aluminum and 1.9 to 2.9 tin and Zirconium 1.8 to 3.0 and 4.5~5.5 molybdenum and 4.2~5.2 chrome and 0.08 to 0.15 oxygen, 0.03 to 0.20 silicone and 0 to 0.30 iron and Titanium and Impurities and The titanium alloy comprising: [2] Percentage by weight based on the total weight of the alloy 5.5~6.5 aluminum and 2.2 to 2.6 tin and Zirconium 2.0-2.8 and Molybdenum 4.8~5.2 and 4.5~4.9 chrome and 0.08 to 0.13 oxygen, 0.03 to 0.11 silicon, 0 to 0.25 iron and Titanium and Impurities and 2. The titanium alloy of claim 1, comprising: [3] Percentage by weight based on the total weight of the alloy 5.9~6.0 aluminum and 2.3 to 2.5 tin and Zirconium 2.3 to 2.6, Molybdenum 4.9~5.1 and 4.5~4.8 chrome and 0.08 to 0.13 oxygen, 0.03 to 0.10 silicone, Iron up to 0.07 and Titanium and Impurities and 2. The titanium alloy of claim 1, comprising: [4] Percentage by weight based on the total weight of the alloy Nitrogen from 0 to 0.05 0 to 0.05 carbon and 0 to 0.015 hydrogen and Niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; 2. The titanium alloy of 1, further comprising: [5] 2. The titanium alloy of claim 1, wherein the titanium alloy has an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 160 ksi at 316°C. [6] 2. The titanium alloy of claim 1, wherein the titanium alloy has an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.8, and exhibits a yield strength of at least 140 ksi at 316°C. [7] 2. The titanium alloy of claim 1, wherein the titanium alloy has an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of at least 20 hours at 427°C under a load of 60 ksi. [8] 2. The titanium alloy of claim 1, wherein the titanium alloy has an aluminum equivalent of 8.0 to 9.5 and a molybdenum equivalent of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 160 ksi at 316°C. [9] 2. The titanium alloy of claim 1, wherein the titanium alloy has an aluminum equivalent of 8.0 to 9.5 and a molybdenum equivalent of 7.4 to 12.8, and exhibits a yield strength of at least 140 ksi at 316°C.

[10] 2. The titanium alloy of claim 1, wherein the titanium alloy has an aluminum equivalent strength of 8.0 to 9.5 and a molybdenum equivalent strength of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of at least 20 hours at 427°C under a load of 60 ksi.

[11] 1. The titanium alloy according to claim 1, Solution treating the titanium alloy at 800°C to 860°C for 4 hours; cooling the titanium alloy to ambient temperature at a rate dependent on the thickness of a cross-section of the titanium alloy; Aging the titanium alloy at 620°C to 650°C for 8 hours; and air cooling the titanium alloy; The titanium alloy is produced by a process comprising:

[12] Percent by weight based on the total weight of the alloy: 5.1~6.1 aluminum and 2.2 to 3.2 tin and Zirconium 1.8 to 3.1 and 3.3~4.3 molybdenum and 3.3 to 4.3 chromium and 0.08 to 0.15 oxygen, 0.03 to 0.20 silicone and 0 to 0.30 iron and Titanium and Impurities and Titanium alloys, including:

[13] Percentage by weight based on the total weight of the alloy 5.1~6.1 aluminum and 2.2 to 3.2 tin and 2.1 to 3.1 zirconium, 3.3~4.3 molybdenum and 3.3 to 4.3 chromium and 0.08 to 0.15 oxygen, 0.03 to 0.11 silicon, 0 to 0.30 iron and Titanium and Impurities and 13. The titanium alloy of claim 12, comprising:

[14] Percentage by weight based on the total weight of the alloy 5.6~5.8 aluminum and 2.5 to 2.7 tin and Zirconium 2.6-2.7 and 3.8~4.0 molybdenum and 3.7 to 3.8 chromium and 0.08 to 0.14 oxygen and 0.03 to 0.05 silicone and Iron up to 0.06 and Titanium and Impurities and 13. The titanium alloy of claim 12, comprising:

[15] Percentage by weight based on the total weight of the alloy Nitrogen of 0 to 0.05 and 0 to 0.05 carbon and 0 to 0.015 hydrogen and Niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; 13. The titanium alloy of claim 12, further comprising:

[16] 13. The titanium alloy of claim 12, wherein the titanium alloy has an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 150 ksi at 316°C.

[17] 13. The titanium alloy of claim 12, wherein the titanium alloy has an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.8, and exhibits a yield strength of at least 130 ksi at 316°C.

[18] 13. The titanium alloy of claim 12, wherein the titanium alloy has an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of 86 hours or greater at 427°C under a load of 60 ksi.

[19] 13. The titanium alloy of claim 12, wherein the titanium alloy has an equivalent aluminum index of 6.9 to 9.5 and an equivalent molybdenum index of 7.4 to 12.8, and exhibits an ultimate tensile strength of at least 150 ksi at 316°C.

[20] 13. The titanium alloy of claim 12, wherein the titanium alloy has an equivalent aluminum index of 8.0 to 9.5 and an equivalent molybdenum index of 7.4 to 12.8, and exhibits a yield strength of at least 130 ksi at 316°C. [twenty one] 13. The titanium alloy of claim 12, wherein the titanium alloy has an aluminum equivalent strength of 8.0 to 9.5 and a molybdenum equivalent strength of 7.4 to 12.8, and exhibits a time to 0.2% creep strain of 86 hours or greater at 427°C under a load of 60 ksi. [twenty two] 13. The titanium alloy according to claim 12, Solution treating the titanium alloy at 800°C to 860°C for 4 hours; cooling the titanium alloy to ambient temperature at a rate dependent on a cross-sectional thickness of the titanium alloy; Aging the titanium alloy at 620°C to 650°C for 8 hours; and air cooling the titanium alloy; The titanium alloy is made by a process comprising: [twenty three] 1. A method of making an alloy, comprising: Solution treatment of a titanium alloy at 800°C to 860°C for 4 hours, wherein the titanium alloy contains 5.5 to 6.5 aluminum, 1.9 to 2.9 tin, 1.8 to 3.0 zirconium, 4.5 to 5.5 molybdenum, 4.2 to 5.2 chromium, 0.08 to 0.15 oxygen, 0.03 to 0.20 silicon, 0 to 0.30 iron, titanium, and impurities; cooling the titanium alloy to ambient temperature at a rate dependent on the thickness of a cross-section of the titanium alloy; Aging the titanium alloy at 620°C to 650°C for 8 hours; and air cooling the titanium alloy; The method comprising: [twenty four] 24. The method of claim 23, wherein the titanium alloy further comprises, in weight percentages based on the total weight of the alloy, 0 to 0.05 nitrogen, 0 to 0.05 carbon, 0 to 0.015 hydrogen, and 0 to a maximum of 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper. [twenty five] 1. A method of making an alloy, comprising: Solution treatment of a titanium alloy at 800°C to 860°C for 4 hours, wherein the titanium alloy contains 5.1 to 6.1% aluminum, 2.2 to 3.2% tin, 1.8 to 3.1% zirconium, 3.3 to 4.3% molybdenum, 3.3 to 4.3% chromium, 0.08 to 0.15% oxygen, 0.03 to 0.20% silicon, 0 to 0.30% iron, titanium, and impurities; cooling the titanium alloy to ambient temperature at a rate dependent on the thickness of a cross-section of said titanium alloy; Aging the titanium alloy at 620°C to 650°C for 8 hours; and air cooling the titanium alloy; The method comprising:

[26] 26. The method of claim 25, wherein the titanium alloy further comprises, in weight percentages based on the total weight of the alloy, 0 to 0.05 nitrogen, 0 to 0.05 carbon, 0 to 0.015 hydrogen, and 0 to a maximum of 0.1 each of niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper.

Claims

1. An alpha / beta titanium alloy comprising, in weight percent based on the total weight of the alloy: Aluminum 5.1 to 6.1, 2.2 to 3.2 tin, 2.1 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, 0.03 to 0.05 silicon, Iron greater than 0 and less than 0.30; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; Titanium and impurities consists of, and containing silicide precipitates and exhibiting a time to 0.2% creep strain of greater than 86 hours at 427°C under a load of 414 MPa (60 ksi); Alpha / Beta titanium alloy.

2. Percentage by weight based on the total weight of the alloy Aluminum 5.6 to 5.8, 2.5 to 2.7 tin, Zirconium of 2.6 to 2.7, 3.8 to 4.0 molybdenum, 3.7 to 3.8 chromium, 0.08 to 0.14 oxygen; 0.03 to 0.05 silicon, Iron greater than 0 and up to 0.06; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; Titanium and 10. The alpha / beta titanium alloy of claim 1, consisting essentially of impurities.

3. 10. The alpha / beta titanium alloy of claim 1, having an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.8, and exhibiting an ultimate tensile strength of at least 1034 MPa (150 ksi) at 316°C.

4. An alpha / beta titanium alloy as described in claim 1, having an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4 to 12.8, and exhibiting a yield strength of at least 896 MPa (130 ksi) at 316°C.

5. 10. The alpha / beta titanium alloy of claim 1 having an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.

8.

6. 10. The alpha / beta titanium alloy of claim 1, wherein the alloy exhibits an ultimate tensile strength of at least 1034 MPa (150 ksi) at 316°C with an equivalent aluminum value of 6.9 to 9.5 and an equivalent molybdenum value of 7.4 to 12.

8.

7. 10. The alpha / beta titanium alloy of claim 1, having an equivalent aluminum value of 8.0 to 9.5 and an equivalent molybdenum value of 7.4 to 12.8, and exhibiting a yield strength of at least 896 MPa (130 ksi) at 316°C.

8. 10. The alpha / beta titanium alloy of claim 1, having an equivalent aluminum value of 8.0 to 9.5 and an equivalent molybdenum value of 7.4 to 12.

8.

9. 10. A method for producing the alpha / beta titanium alloy of claim 1, comprising: solution treating the titanium alloy at 800°C to 860°C for 4 hours; water quenching the titanium alloy to ambient temperature; Aging the titanium alloy at 620°C to 650°C for 8 hours; and air cooling the titanium alloy; A method comprising:

10. 1. A method for producing an alpha / beta titanium alloy, comprising: Solution treating a titanium alloy at 800°C to 860°C for 4 hours, wherein the alpha / beta titanium alloy comprises, in weight percent based on the total weight of the alloy: Aluminum 5.1 to 6.1, 2.2 to 3.2 tin, 2.1 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, 0.03 to 0.05 silicon, Iron greater than 0 and less than 0.30; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; Titanium and It consists of impurities, water quenching the titanium alloy to ambient temperature; Aging the titanium alloy at 620°C to 650°C for 8 hours; and air cooling the titanium alloy; Including, the alpha / beta alloy contains silicide precipitates and exhibits a time to 0.2% creep strain of greater than or equal to 86 hours at 427°C under a load of 414 MPa (60 ksi); method.

11. An alpha / beta titanium alloy comprising, in weight percent based on the total weight of the alloy: Aluminum 5.1 to 6.1, 2.2 to 3.2 tin, 2.1 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, Silicon of 0.03 to 0.20, 0 to 0.1 copper, Iron greater than 0 and less than 0.30; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, and cobalt, each at 0 to a maximum of 0.1; Titanium and impurities consists of, and containing silicide precipitates and exhibiting a time to 0.2% creep strain of greater than 86 hours at 427°C under a load of 414 MPa (60 ksi); Alpha / beta titanium alloy.

12. Percentage by weight based on the total weight of the alloy 5.6 to 5.8 aluminum, 2.5 to 2.7 tin, Zirconium of 2.6 to 2.7, 3.8 to 4.0 molybdenum, 3.7 to 3.8 chromium, 0.08 to 0.14 oxygen, 0.03 to 0.05 silicon, 0 to 0.1 copper, Iron greater than 0 and less than 0.06; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, and cobalt, each at 0 to a maximum of 0.1; Titanium and 12. The alpha / beta titanium alloy of claim 11, consisting essentially of impurities.

13. 12. The alpha / beta titanium alloy of claim 11, having an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.8, and exhibiting an ultimate tensile strength of at least 1034 MPa (150 ksi) at 316°C.

14. The alpha / beta titanium alloy of claim 11, having an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4 to 12.8, and exhibiting a yield strength of at least 896 MPa (130 ksi) at 316°C.

15. 12. The alpha / beta titanium alloy of claim 11 having an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.

8.

16. 12. The alpha / beta titanium alloy of claim 11, wherein the alloy exhibits an ultimate tensile strength of at least 1034 MPa (150 ksi) at 316°C with an equivalent aluminum value of 6.9 to 9.5 and an equivalent molybdenum value of 7.4 to 12.

8.

17. 12. The alpha / beta titanium alloy of claim 11, having an equivalent aluminum value of 8.0 to 9.5 and an equivalent molybdenum value of 7.4 to 12.8, and exhibiting a yield strength of at least 896 MPa (130 ksi) at 316°C.

18. 12. The alpha / beta titanium alloy of claim 11 having an equivalent aluminum value of 8.0 to 9.5 and an equivalent molybdenum value of 7.4 to 12.

8.

19. An alpha / beta titanium alloy comprising, in weight percent based on the total weight of the alloy: Aluminum 5.1 to 6.1, 2.2 to 3.2 tin, 2.1 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, Silicon of 0.03 to 0.20, 0 to 0.1 vanadium, Iron greater than 0 and less than 0.30; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; Titanium and impurities consists of, and containing silicide precipitates and exhibiting a time to 0.2% creep strain of greater than 86 hours at 427°C under a load of 414 MPa (60 ksi); Alpha / beta titanium alloy.

20. Percentage by weight based on the total weight of the alloy 5.6 to 5.8 aluminum, 2.5 to 2.7 tin, Zirconium of 2.6 to 2.7, 3.8 to 4.0 molybdenum, 3.7 to 3.8 chromium, 0.08 to 0.14 oxygen, 0.03 to 0.05 silicon, 0 to 0.1 vanadium, Iron greater than 0 and up to 0.06; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; Titanium and 20. The alpha / beta titanium alloy of claim 19, consisting essentially of impurities.

21. 20. The alpha / beta titanium alloy of claim 19, having an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of between 7.4 and 12.8, and exhibiting an ultimate tensile strength of at least 1034 MPa (150 ksi) at 316°C.

22. The alpha / beta titanium alloy of claim 19, having an aluminum equivalent of at least 6.9 and a molybdenum equivalent of 7.4 to 12.8, and exhibiting a yield strength of at least 896 MPa (130 ksi) at 316°C.

23. 20. The alpha / beta titanium alloy of claim 19, having an equivalent aluminum value of at least 6.9 and an equivalent molybdenum value of 7.4 to 12.

8.

24. 20. The alpha / beta titanium alloy of claim 19, having an equivalent aluminum value of 6.9 to 9.5 and an equivalent molybdenum value of 7.4 to 12.8, and exhibiting an ultimate tensile strength of at least 1034 MPa (150 ksi) at 316°C.

25. 20. The alpha / beta titanium alloy of claim 19, having an equivalent aluminum value of 8.0 to 9.5 and an equivalent molybdenum value of 7.4 to 12.8, and exhibiting a yield strength of at least 896 MPa (130 ksi) at 316°C.

26. 20. The alpha / beta titanium alloy of claim 19, having an equivalent aluminum value of 8.0 to 9.5 and an equivalent molybdenum value of 7.4 to 12.

8.

27. An alpha / beta titanium alloy comprising, in weight percent based on the total weight of the alloy: Aluminum 5.1 to 6.1, 2.2 to 3.2 tin, 2.1 to 3.1 zirconium, 3.3 to 4.3 molybdenum, 3.3 to 4.3 chromium, 0.08 to 0.15 oxygen, Silicon of 0.03 to 0.20, Iron greater than 0 and less than 0.30; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; Titanium and impurities consists of, and containing silicide precipitates and exhibiting a time to 0.2% creep strain of greater than 86 hours at 427°C under a load of 414 MPa (60 ksi); Alpha / beta titanium alloy.

28. Percentage by weight based on the total weight of the alloy 5.6 to 5.8 aluminum, 2.5 to 2.7 tin, Zirconium of 2.6 to 2.7, 3.8 to 4.0 molybdenum, 3.7 to 3.8 chromium, 0.08 to 0.14 oxygen, 0.03 to 0.05 silicon, Iron greater than 0 and up to 0.06; 0 to 0.05 nitrogen; 0 to 0.05 carbon; 0 to 0.015 hydrogen; niobium, tungsten, hafnium, nickel, gallium, antimony, vanadium, tantalum, manganese, cobalt, and copper, each at 0 to a maximum of 0.1; Titanium and impurities consists of, and containing silicide precipitates and exhibiting a time to 0.2% creep strain of greater than 86 hours at 427°C under a load of 414 MPa (60 ksi); Alpha / Beta titanium alloy.

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