Cheap alpha-beta titanium alloy with good ballistic and mechanical properties

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, particularly to titanium alloys with enhanced ballistic and mechanical properties. Titanium alloy includes mainly the following components, wt %: aluminium 4.2-5.4, vanadium 2.5-3.5, iron 0.5-0.7, oxygen 0.15-0.19, and the rest is titanium.

EFFECT: titanium-based alloy obtained from recycled materials shows minimum ballistic limit V50 of ca 1848 ft/sec, and high characteristics of yield strength, tensile strength and elongation.

23 cl, 6 dwg, 4 tbl, 1 ex

 

This application is a PCT International application which claims the benefits of the unconditional application for U.S. patent No. 12/850691, registered on August 5, 2010, which is thereby incorporated by reference.

The technical field to which the invention relates

This invention relates primarily to alloys of titanium (Ti). In particular, as described alpha-beta Ti alloys having an improved combination of ballistic and mechanical properties achieved with relatively cheap composition and methods of production of Ti alloys.

The level of technology

The Ti alloys have found wide use in applications requiring high strength-to-weight ratio, good corrosion resistance and preservation of these properties at elevated temperatures. Despite these advantages, more expensive raw materials and processing costs of Ti alloys compared to steel and other alloys, have severely limited their use in applications where the need for improved efficiency and performance outweighs their relatively higher cost. Some typical applications that will benefit from the inclusion of Ti alloys in varying amounts include, for example, structural elements of the aircraft, medical devices, cars with high performance sports equipment with higher�and military applications.

Conventional titanium base alloy which has been successfully used in military systems, is Ti-6A1-4V, which is also known as Ti64. As the name suggests, these alloys usually include Ti 6 wt.% aluminium (Al) and 4 wt.% vanadium (V) and to 0.30 wt.% iron (Fe) and to 0.30 wt.% oxygen (O).

Development of Ti64 offers alloy having an attractive combination of ballistic and mechanical properties for military ground vehicle systems. Military uses, which provides a weldable wrought titanium alloy, such as Ti64, such as structural armor plate, usually have strict compositional and performance requirements. For example, in the document titled "Detailed Specification: Armor plate, Titanium Alloy, Weldable," M1L-DTL-46077G, 2006, the U.S. Department of defense has identified conditions for the four classes Ti64, armor wrought titanium alloy, certain strict interval of the elemental composition and density requirements as well as minimal mechanical and ballistic properties. As for armor plate on the basis of Ti alloy, the goal, therefore, is to provide Ti alloys that meet or exceed standards, minimizing raw material costs and processing costs.

A number of approaches was tracked in an attempt to produce Ti alloys have�their given combination of properties at lower cost. For example, the Ti alloys were produced by a single electron beam melting (OELP). This approach has made the production of Ti alloys is more cost-effective and made possible their further implementation in military systems. Another approach focused on the replacement of the amount of iron (Fe) instead of vanadium (V) as a beta stabilizer in the Ti alloy to reduce the cost of raw materials, as disclosed, for example, U.S. patent No. 6786985 from Kosaka (Kosaka), etc. (hereinafter "Kosaka"). However, the Ti alloy developed by Kosaka, demanded the inclusion of molybdenum (Mo).

Another approach included the development of Ti alloy compositions that permit the processing of the ingot metal in the final rolled product at temperatures completely within the field of beta-phase alloy, as disclosed, for example, in U.S. patent No. 5342458 from Adams and others ("Adams"). Adams argues that higher ductility and a lower voltage, causing the plastic deformation, which exists at higher temperatures in the described alloys, minimize surface and face of the crack, therefore increasing performance. U.S. patent No. 5980655 from Yoji Kosaka and U.S. patent No. 5332 45 from William B. Lava uncover approaches in which the Ti64 alloys having improved mechanical and ballistic properties, formed by increasing the concentration of oxygen in excess of the interval�in, identified by standard military guidelines.

A number of Ti alloys having compositions similar to Ti64, but included with additional components, also known in the technology. These Ti alloys were developed to ensure, among other things, of cheap high-strength Ti alloys with acceptable levels of ductility. An example is proposed in U.S. patent No. 7008489 from Paul j. Banii, which, in one embodiment of the implementation, reveals the Ti alloy, having at least 20% improvement in ductility at a given strength level. However, in addition to the basic components of Ti-Al-V-Fe-O, present in Ti64, unveiled the alloy also includes the concentration of tin (Sn), zirconium (Zr), chromium (Cr), molybdenum (Mo) and silicon (Si). A large number of elements present in these alloys, inevitably increases the cost of the materials thus formed of Ti alloy.

Another example proposed by the patent application U.S. No. 2006/0045789 from Maserati, etc. ("Maserati"), aimed at Ti alloys that can be produced from reusable titanium. In one embodiment, the implementation of Maserati discloses an alloy of Ti, including Ti-Al-V; however, the alloy also includes one or more elements selected from the group consisting of Cr, Fe and manganese (Mn) at concentrations from 1.0 to 5.0 wt.%. Relatively high levels of Cr, Fe and MP and low plasticity Ogre�icipat the use of alloy for military systems. Each of the above patents and patent applications incorporated by reference in their entirety as if they were fully set forth herein.

Despite improvements from the point of view of composition, properties and processing costs that have been achieved to date, there is a continuing need to develop new and improved alloys of Ti, and the associated manufacturing methods that achieve the minimum mechanical and ballistic performance levels at a constant lower value.

Summary of the invention

Proposed Ti alloy having a good combination of ballistic and mechanical properties, which are achieved using a cheap composition. The Ti alloy is particularly useful for use as armor plate for military applications, but is not so limited and may be suitable for many other applications. In one embodiment, the implementation of the Ti alloy consists essentially of, in weight percent, from 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium, 0.5 to 0.7% iron, 0.15 to 0.19% oxygen and titanium to 100%. In a particular embodiment of the Ti alloy consists essentially of, in weight percent, approximately 4.8% aluminum, about 3.0% vanadium, about 0.6% of iron, about 0.17 percent of oxygen and titanium to 100%. In yet another embodiment of the maximum contamination level�radio of any one impurity element, the presence in the alloy of titanium, 0.1 wt.%, and the combined concentration of all impurities is 0.4 wt.% or less.

The Ti alloys having the disclosed compositions have the advantage to provide low-Ti alloy, which includes the yield strength in tension (MFR) of at least about 120000 pounds per square inch (approximately 8440 kg/cm2) and ultimate tensile strength (TD) of at least 128000 psi (approximately 9000 kg/cm2) in both the longitudinal and transverse directions in combination with narrowing cross-sectional area (PCA) of at least about 43%, and an elongation of at least about 12%. The Ti alloy can be formed in the sheet in a specific embodiment, the implementation has a thickness of from about 0,425 inches to approximately is 0.450 inches (from about 1.08 to approximately 1.14 cm) and the ballistic limit V50at least about 1848 feet per second (563 km/h). In another more specific embodiment of the sheet of Ti alloy has a thickness of approximately 0,430 inches (about 1,09 cm) and the ballistic limit V50approximately 1936 feet per second (590 km/h).

In one embodiment, the implementation of the Ti alloy has a ratio of beta isomorphous (βiso) stabilizer to beta macroeconomia (βeut) one hundred�ilitator (β isoeut) from about 0.9 to about 1.7, where βisoeutdefined as

βISOβEUT=Mo+V1.5Cr0.65+Fe0.35

In the equations proposed in this description, Mo, V, CR and Fe, respectively, represent the weight percent of molybdenum, vanadium, chromium and iron in the alloy Ti. In a specific embodiment, the implementation of the beta-isomorphous beta stabilizer to-macroeconomia the stabilizer is approximately 1.2.

In another embodiment, the implementation of the Ti alloy has a molybdenum equivalent (Moeq) from about 3.1 to about $ 4.4, in which the molybdenum equivalent is defined as

Moeq=Mo+V1.5+Cr0.65+Fe0.35

In a particular embodiment of the molybdenum equivalent is approximately 3.8 In another embodiment, the implementation of the Ti alloy has an aluminum equivalent (Al eq) from about 8.3 to approximately 10.5, in which the aluminum equivalent is defined as

Aleq=Al+27O

In this equation, Al and O represent the weight percent of aluminum and oxygen, respectively, in the alloy Ti. In a particular embodiment of the aluminum is approximately equivalent to 9.4.

In another embodiment, the implementation of the Ti alloy has a temperature of beta-transformation (Tβ) from about 1732°F (783°C) to about 1820°F (833°C), where the temperature of the beta-transformation, in °F, is defined as

Tβ=1607+39,3 Al+330O+1145C+1020N-21,8 V-32,5 Fe-17,3 Mo-70Si-27,3 Cr.

In this equation, N and Si represent the weight percent of carbon, nitrogen and silicon, respectively, in the alloy Ti. In a particular embodiment of the temperature of the beta-transformation is approximately 1775°F (806°C). In one embodiment of the density of the alloy Ti varies from approximately 0,161 pounds per cubic inch to about 0,163 pounds per cubic inch (from approximately to approximately 4,46 4,51 g/cm3and, in a specific embodiment, the implementation is approximately 0,162 pound per cubic inch (approximately 4.48 g/cm3).

In another embodiment of the disclosed method of producing Ti alloy, consisting essentially of, in weight percent, from 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium, 0.5 to 0.7% iron, 0.15 �about 0.19 percent of oxygen and titanium to 100%. In a particular embodiment of the Ti alloy is produced by melting a combination of reusable and/or raw materials containing appropriate ratios of aluminum, vanadium, iron and titanium, in a cold hearth furnace to form a molten alloy, and casting the specified molten alloy into the mold. Recyclable materials may include, for example, shavings Ti64 and commercially pure (PM) titanium waste. Fresh raw materials may include, for example, sponge titanium, iron powder, and the fraction of aluminium. In another specific embodiment, the implementation of reusable materials contain approximately 70,4% chips Ti64, approximately 28,0% sponge titanium, about 0.4% of iron powder and approximately 1.1% of the fraction of aluminum.

In yet another embodiment of the Ti alloy is cast in a rectangular shape to form a sheet having a rectangular shape, and composition, in weight percent, from 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium, 0.5 to 0.7% iron, 0.15 to 0.19% oxygen and titanium to 100%. In a particular embodiment of the molded sheet may be subjected to initial forging or rolling at a temperature above the beta-transus and final rolling at a temperature below the beta-transus before being annealed at a temperature below the beta-transus.

The Ti alloys disclosed in this description, provide a relatively cheap alternative to regular Ti64 alloys, responding to mechanical and ballistic properties set for Ti64 alloys. This reduction will enable broader adoption of Ti alloys in many military and other applications that require similar combinations of properties.

Brief description of the drawings

Accompanying figures, which are incorporated and constitute part of this disclosure, illustrate typical embodiments of the disclosed invention and serve to explain the principles of the invention disclosed.

Fig.1 is a block diagram for explaining the method of producing Ti alloys in accordance with embodiments of the invention disclosed.

Fig.2A is a diagram of the actual armor-piercing caliber.30 M2 cartridge.

Fig.2B is a photo of an actual armor-piercing caliber.30 M2 cartridge used in the actual test.

Fig.3 shows the configuration of the interval test used to test the ballistic limit V50 armor plates.

Fig.4 is an example showing the probability of penetration of armor plate from the speed of the munition, as measured at the midpoint between the barrel and armor plate.

Fig.5 is a graph showing the ballistic limit V50�AK function of thickness for a typical Ti alloys.

Fig.6 is an enlarged view of Fig.5 in the interval thickness from 0.40 to 0.46 inches (from 1.0 to 1.16 cm), showing the ballistic limit V50as a function of thickness for a typical Ti alloys.

Throughout the drawings the same numerals and symbols references, unless otherwise indicated, used to denote similar features, elements, components, or parts explained embodiments. Although the disclosed invention is described in detail with reference to the drawings, it is done so in connection with illustrative embodiments of the implementation.

Detailed description of the invention

Describes a typical Ti alloys having good mechanical and ballistic properties, which were obtained using relatively cheap materials. These Ti alloys are particularly suitable for use as armor plate for military systems or for applications that require a metal alloy having an excellent strength-weight and good resistance to piercing ammunition after impact. The disclosed alloys Ti reach of combinations of mechanical strength and ballistic properties that meet minimum military standards, lowering the cost of composition and processing. Cheaper raw materials and processing costs will facilitate more widespread adoption of the disclosed Ti alloys due to their more and Bo�its favorable cost considerations.

In a typical embodiment of the Ti alloy includes, in weight percent, from 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium, 0.5 to 0.7% iron, 0.15 to 0.19% oxygen and titanium up to 100% and incidental impurities.

Aluminum as an alloying element in titanium is an alpha stabilizer, which increases the temperature at which the alpha phase is stable. In one embodiment of the aluminum is present in the Ti alloy, in weight percent, from 4.2 to 5.4%. In a specific embodiment, the aluminum is present in amounts of about 4.8 wt.%.

Vanadium as an alloying element in titanium is isomorphous beta stabilizer which lowers the temperature of the beta-transformation. In one embodiment of the vanadium is present in the Ti alloy, in weight percent, from 2.5 to 3.5%. In a specific embodiment, the vanadium is present in an amount of about 3.0 wt.%.

Iron as alloying element in titanium is macrodomain beta stabilizer which lowers the temperature of the beta-transformation, and iron is a reinforcing element in titanium at ambient temperatures. In one embodiment of the iron is present in the Ti alloy, in weight percent, from 0.5 to 0.1%. In a particular embodiment of the iron is present in an amount of about 0.6 wt.%. If, however, the iron concentration will exceed the upper limits disclosed in this description, it can cause excessive segregation of solute during solidification of the ingot, which will have a negative impact on the ballistic and mechanical properties. On the other hand, the use of iron levels below the limits disclosed in this description, can produce an alloy that is not able to achieve the desired strength and ballistic properties. Oxygen as an alloying element in titanium is an alpha stabilizer, and oxygen is an effective hardening element in titanium alloys at ambient temperatures. In one embodiment of the oxygen present in the Ti alloy, in weight percent, from 0.15 to 0.19%. In a particular embodiment of the oxygen is present in an amount of about 0.17 wt.%. If the oxygen content is too low, the strength may be too low, the temperature of the beta-transformation may be too low, and the cost of the alloy Ti may increase, because the scrap is not suitable for use in the melting of the alloy Ti. On the other hand, if the oxygen content is too large, resistance to cracking upon ballistic impact can be degraded. In accordance with some embodiments of implementation of the present invention, the Ti alloy may also include incidental impurities or other elements, such as Mo, Cr, N, C, Nb, Sn, Zr, Ni, Co, Cu, Si, etc., in concentrations associated with the level of impurities. Nitrogen (N) may also be present in concentrations up to a maximum of 0.05 wt.%. In a particular embodiment of the maximum concentration of any impurity element is 0.1 wt.%, and the combined concentration of all impurities does not exceed a total of 0.4 wt.%.

In accordance with one variant of implementation of the Ti alloy has a ratio of beta isomorphous (Piso) stabilizer to beta macroeconomia (βiso) stabilizer to beta macroeconomia (βeut) to the stabilizer (βisoeut) from about 0.9 to about 1.7, where βisoeutdefined as

βISOβEUT=Mo+V1.5Cr0.65+Fe0.35(1)

In equations, this description of Mo, V, Cr and Fe respectively represent the weight percent of molybdenum, VANAD�I, chromium and iron in the alloy Ti. In a specific embodiment, the implementation of the beta-isomorphous beta stabilizer to-macroeconomia the stabilizer is about 1.2.

In accordance with another variant implementation of the invention, the Ti alloy has a molybdenum equivalent (Moeq) from about 3.1 to about 4.4, in which the molybdenum equivalent is determined in equation (2) as

Moeq=Mo+V1.5+Cr0.65+Fe0.35(2)

In a particular embodiment of the molybdenum equivalent is about 3.8. Although Mo and Cr are not primary components of the disclosed Ti alloy, they may be present in trace concentrations (for example, when the level of impurities or below) and can therefore be used to compute βisoeutand Moeq. In another embodiment, the implementation of the Ti alloy has an aluminum equivalent (Aleq) from about 8.3 to about 10.5, in which the aluminum equivalent of about�Radelet in equation (3) as

Aleq=Al+27O(3)

In this equation, Al and O represent the weight percent of aluminum and oxygen, respectively, in the alloy Ti. In a particular embodiment of the aluminum is about equivalent to 9.4.

In another embodiment, the implementation of the Ti alloy has a temperature of

beta-transformation (Tβ) from about 1732°F (783°C) to about 1820°F

(833°C), where the temperature of the beta-conversion into °F is determined by equation (4) as

Tβ=1607+39,3Al+330O+1145C+1020N-21,8V-32,5Fe-17,3Mo-70Si-27,3Cr(4)

In this equation C, N and Si represent wt.% carbon, nitrogen and silicon, respectively, with�lava Ti. As in the case of molybdenum equivalent, although C, N and Si are not primary components of the Ti alloy, they may be present as incidental impurities.

In a particular embodiment of the temperature of the beta-transformation is about 1775°F (806°C).

Alloys Ti achieve excellent mechanical properties tensile, and have, for example, the yield strength in tension (MFR) of at least 120,000 psi (8440 kg/cm2) and ultimate tensile strength (TD) of at least about 128000 psi (9000 kg/cm2) both along the transverse and the longitudinal directions. In another embodiment, the implementation of the Ti alloy has an elongation of at least about 12%, and/or a relative narrowing of the cross-sectional area (PCA) of at least about 43%. As calculated, the density of Ti alloy is 0,161 pounds per cubic inch to about 0,163 (from about to about 4,46 4,51 g/cm3) with a nominal density of about 0,162 pound per cubic inch (about 4.48 g/cm3).

The Ti alloy also provides excellent ballistic properties. Measure the effectiveness of ballistic sheets provided by the average speed (V50) shell or ammunition required for punching the sheet. For example, when the formed sheets having a thickness of from about 0,425 to about 0.450 inches (from about 1.08 to about 1.14 cm),the Ti alloy has a ballistic limit V 50at least about 1848 feet per second (563 km/h). In a specific embodiment, the implementation for sheet thickness of about 0,430 inch (1,09 cm) alloy Ti has a ballistic limit V50about 1936 feet per second (590 km/h). The methodology used in the testing of ballistic limits of V50Ti alloys described with reference to the examples described below.

In accordance with another variant of implementation of the proposed sheet consisting of Ti alloy described in this description. In a particular embodiment of the alloy Ti presented here is used as an armor sheet. However, other suitable applications for the alloy include Ti, but are not limited to, other components in military systems, such as automobile parts and aircraft, such as chair rails and protective screens from erosion.

In yet another embodiment of the disclosed method of producing Ti alloy having good mechanical and ballistic properties. The method includes melting a combination of source materials in the appropriate proportions to produce Ti alloy, consisting essentially, in weight percent, from 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium, 0.5 to 0.7% iron, 0.15 to 0.19% oxygen and titanium to 100%. Melting can be achieved, for example, in a cold hearth furnace. In a specific embodiment, the implementation and�packing materials include a combination of recycled and fresh raw materials, such as waste titanium, and sponge titanium in combination with small amounts of iron and aluminum. Under most market conditions, the use of recycled materials offers a significant cost reduction. Use reusable materials may include, but are not limited to, Ti64, Ti-10V-2Fe-3Al, other alloys Ti-Al-V-Fe and CP titanium. Reusable materials can be in the form of a waste processing machine (shavings), solid pieces or melted electrodes. Used fresh raw materials may include, but are not limited to, spongy titanium, alloy of aluminum-vanadium, iron powder or aluminum fraction. As no ligature aluminium-vanadium steel is not required, significant cost reduction can be achieved. This, however, does not preclude the use and addition of fresh raw material including the titanium sponge and alloying elements, and is not re-used materials, if desired. In some embodiments, the method of production involves performing annealing heat treatment of Ti alloy at a temperature of subtruncata (e.g. temperature below the beta-transformation). Used Ti alloy may have any of the properties described in this description.

In some embodiments, the production method also includes VA�wolny arc remelting (VEP) alloy and forging and/or rolling of Ti alloy above the temperature of the beta-transformation, followed by forging and/or rolling temperature below the beta-transformation. In a specific embodiment of the production method of Ti alloy is used to produce components of military systems, and more specifically, to produce armor plate.

A block diagram that shows a typical method of production of Ti alloys shown in Fig.1. Initially, the desired quantity of raw materials having the appropriate concentrations and ratios, preparing to stage 100. In a particular embodiment of the raw materials include recycled materials, although they can be combined with fresh raw materials corresponding to the composition in any combination. After preparation of the raw material is melted and cast to produce an ingot of metal in the stage 110. Melting can be achieved, for example, VEP, plasma arc melting, electron beam melting, in skull melting furnace or a combination of both. In a particular embodiment of the double ingots smelting receive the VEP and cast right into a round shape.

In stage 120, the metal ingot is subjected to initial forging and rolling. Initial forging and rolling is performed above the temperature of the beta-transformation (beta transus), and perform rolling in the longitudinal direction. In stage 130, the metal ingot p�will gorhaut final forging and rolling. End forging and rolling perform a temperature below the beta-transformation (beta transus), and rolling vypolniaut in the longitudinal and transverse directions. The metal ingot is then annealed in stage 140, which, in a specific embodiment, the implementation is performed at a temperature of subtruncata. Ultimate car may have a thickness that varies, but is not limited to, from about 0.1 inches to about 4.1 inches (about 0.25 cm to about 10.4 cm).

In some embodiments, the rolling up to a size lower than 0.4 inch (1 cm) can be achieved by hot rolling, optionally cold rolling to produce a roll or strip. In yet another embodiment of the rolling up of thin sheet products can be achieved by hot or cold rolling of sheets to separate sheets or to sheets, Packed in steel bundles.

Further details of a typical titanium alloys and methods for their production are described in the examples that follow below.

Examples

The examples presented in this section serve to illustrate the used processing stage, the final composition and consequent properties of Ti alloys obtained according to embodiments of the present invention. The Ti alloys and related methods of their production, as described below, proposed as an example�in and are not limiting.

Comparative examples

Several Ti alloys with concentrations of elements outside the intervals V, Fe, and O, disclosed in this description, were originally obtained, to serve as comparative examples. Comparative Ti alloys were obtained by mixing together raw materials to achieve appropriate ratios for each of the comparative Ti alloy. Comparative Ti alloy No. C1 were obtained with a nominal composition of about 5.0 wt.% aluminum, about 4.0 wt.% vanadium, about 0.03 wt.% iron, about 0.22 wt.% oxygen and titanium to 100%. Comparative Ti alloy No. C2 were obtained with a nominal composition of about 5.0 wt.% aluminum, about 4.0 wt.% vanadium, about 0.03 wt.% iron, about 0.12 wt.% oxygen and titanium up to 100%". Comparative Ti alloy No. NW was acquired with a nominal composition of about 5.0 wt.% aluminum, about 5.0 wt.% vanadium, about 0.6 wt.%) iron, about to 0.19 wt.% oxygen and titanium to 100%.

Comparative Ti alloys No. C1-C3 were cast into individual ingots of metal having a circular shape, and transformed into an intermediate slab above the temperature beta transus. Final rolling and cross-rolling was performed below the temperature beta transus. The final annealing is performed at a temperature below the beta-transus. Comparative Ti alloys No. C1-C3 were subjected to final annealing at a temperature of 1400°F (760°C) for two hours, and the samples were allowed okhla�be given in the air.

Chemical analysis was performed on the comparative Ti alloys No. C1-C3, and measured their mechanical and ballistic properties. The measured compositions and calculated values of Aleq, Moeq, Tβand density are summarized in table 1 below:

Table 1. Chemical compositions and parameters of comparative Ti alloys No. C1-C3
Alloy TiElement (wt. %)The calculated sample
AlVFeONAleqMoeqTβ, °F (°C)ρ, pound/cubic inch (g/cm3)
C14,984,10,030,220,00311,02,81796 (980)0,161 (4,46)
C2of 4.954,10,03 0,120,0018,12,81761 (960,5)0,162(4,48)
C34,814,920,580,190,0029,95,01742 (950)0,163 (4,51)

The mechanical properties of the sheets including comparative Ti alloys No. C1-C3, were measured and summarized in table 2. Multiple measurements were obtained on the same metal bars and the results are shown in separate lines within the same group in table 2. Elongation properties of the sheets were measured in transverse (Pop.), and longitudinal (Cont.) directions. In table 2 ksi has a value of kilaguni per square inch (1 kilopound per square inch=1000 pounds per square inch). Elongation properties measured in table 2 give the average values of RMR, q, ATP and Lengthening 131 Kropotov per square inch (9210,21 kg/cm2), 122,3 of Kropotov per square inch (8598,54 kg/cm2), 36% and 10.3%, respectively, for comparative Ti alloy No. C1; 131 Kropotov per square inch (9210,21 kg/cm2), 123 Kropotov per square inch (8647,76 kg/cm2), 34 and 11%, accordingly, for comparative Ti alloy No. C2; and 133,8 of Kropotov per square inch (9407,07 kg/cm2), 124,3 of Kropotov per square inch (8739,16 kg/cm2), 42% and 12.3%, respectively, for comparative Ti alloy No. C3.

Table 2. Summary of tensile properties of comparative Ti alloys No. C1-C3
Alloy TiThe nominal composition (wt.%)Elongation properties
OrientationPPP, kilopound per square inch (kg/cm2)AV, kilopound per sqm
inch (kg/cm2)
ATP (%)Elongation (%)
C1(a) C1(b) C1(c)5Al4V.03 Fe.22O 5Al4V.03 Fe.22O 5Al4V.03 Fe.22OCont.133 (9350,83)124 (8718,07)3511
Cont.129 (9069,6)121 (8507,14)3711
Pop.131 (9210,21)122 (857,45) 369
C2(a) C2(b) C2(c)5Al4V.03 Fe.12O 5Al4V.03 Fe.12O 5Al4V.03 Fe.12OCont.131 (9210,21)123 (8647,76)3511
Cont.131 (9210,21)123 (8647,76)3311
Pop.131 (9210,21)123 (8647,76)3411
C3(a) NW(b) C3(C) C3(d)5Al5V.6Fe.l9O 5Al5V.6 Fe.19-5Al5V.6Fe.19-5Al5V.6Fe.19 - Cont.135 (9491,44)125 (8788,37)4312
Cont.135 (9491,44)125 (8788,37)4313
Pop.133 (9350,83)124 (8718,07)3812
Pop. 132 (9280,52)123 (8647,76)4412

Minimum protective ballistic limits V50sheets of comparative Ti alloys was measured using.30 caliber (7.62 mm) 166-groovie armor piercing (BB) ammunition M2. The transverse cross section.30 BB cartridge M2 shown in Fig.2A, whereas the actual sample is shown in Fig.2B. Ammunition caliber.30 include a core of hardened steel, the composition to fill the cavity in the head portion of the bullet shell and gold-plated metal shell. Needless ballistic testing was conducted in accordance with standard military testing procedures, as disclosed, for example, the U.S. Department of defense "Military Standard: Ballistic Test V50for Armor," MIL-STD-662E, 2006.

Schematic configuration of intervals test used to test the ballistic limit V50armor plate shown in Fig.3. First and second photoelectric screen used in conjunction with the chronograph to calculate the speed of the munition at a point halfway between the muzzle and the target. Testing was performed at zero degrees deviation in environmental conditions (70-75°F (21-24°C) and 35-75% relative humidity). The thickness of each sheet is an average of thicknesses measured at each�Lou sheet. Sheet-witness of aluminum 2024-T3 thickness of a 0.020 inch (0.51 mm) was placed 6 inches (152 mm) behind the target sheet. Any hole sheet witness was defined as the complete penetration of the test specimen armor.

Each test consisted of firing ammunition at various speeds, and then estimating whether a certain shock to full penetration (i.e. the hole in the sheet-witness) or to partial penetration. The average speed of the lowest full prebivanii and the highest partial prebivanii then used to estimate the value of V50. The results of the calculation of the sample proposed in Fig.4 is a graph showing the likelihood of penetration (%) as a function of impact velocity (ft/sec) for the thickness of the alloy Ti 0,430 inch (1,09 cm). The method of production, composition and properties of Ti alloy sheet, tested in Fig.4 shown in example 1 below. Solid diamonds in Fig.4 represent the cartridges, which are partially punched (PE) sheet, whereas the solid squares represent the full penetration (PP) sheet. The V50 value is calculated by averaging the velocities of collisions producing PP, with collisions that produce emergency. The example in Fig.4 represents the value of V50=1936 ft/s (580 m/s). Therefore, the value of V50is the appropriate number to describe and has been widely used to determine�ü the number of ballistic protection, under the given armor type against this threat.

Comparative Ti alloys have been processed so as to obtain sheets having a thickness of about 0,440 inch (1,12 cm) for comparative Ti alloy No. C1, about 0,449 inch (1,14 cm) for comparative Ti alloy No. C2 and about 0,426 inches (1.08 cm) for comparative Ti alloy No. C3. Ballistic properties of each of comparative Ti alloys No. C1-C3 were measured according to the standards of the Ministry of defense, as defined above in relation to Fig.2-4, and the results are summarized in table 3 below. Ballistic limit V50for comparative Ti alloys No. C1-C3, as measured, is about 1922 ft/sec (576,6 km/h), about 1950 ft/sec (585 km/h) and about 1888 ft/sec (566,4 km/h), respectively.

Ballistics calculated for Ti64 alloys, having a thickness of the sheet, identical to the experimental value obtained for comparative Ti alloys No. C1-C3 are also shown in table 3. Improvement V50 obtained between each comparative Ti alloy and the design value of V50 for Ti64 labeled as Ti64 And against" and include in the right hand column of table 3. The values of V50for Ti alloys No. C1-C3 exceed the calculated values for Ti64 sheet having the same thickness, 10, 12, and 16 ft/sec (3, 3.6 and 4.8 m/sec), respectively. The minimum value of V50presented in table 3 represent the minimum value Vsub> 50required by the U.S. Department of defense in MIL-DTL-46077G, 2006 for the specified thicknesses of the sheets. For example, the thickness of the sheet 0,440 inch (1,12 cm) requires a minimum V50equal to 1895 ft/sec (568,5 km/h). The values of AV50presented in table 3, represent the difference between the minimum V50and measured values of V50for each comparative Ti alloy.

Table 3
Summary of ballistic results for comparative Ti alloys No. C1-C3
Alloy TiThe nominal composition (wt.%)The results of the V5 (a)for these alloysCalculated Y50for Ti64D
Thickness, inches (cm)V50min, ft/sec (m/sec)V50ft/sec (m/sec)AV50ft/sec (m/sec)Thickness, inches (cm)V50min, ft/sec (m/sec)V50ft/sec (m/sec)AV50ft/sec (m/sec)relatively Ti64, ft/s�K (m/sec)
C15Al4V.03Fe.2200,440 (1,12)1895 (568,5)1922 (576,6)27 (8,1)0,440 (1,12)1895 (568,5)1912 (573,6)17 (5,1)10(3)
C25Al4V.03Fe.12O0,449 (1,14)1922 (576,6)1950 (585)28 (8,4)0,449 (1,14)1922 (576,6)1938 (581.4)16 (4,8)12(3,6)
NW5Al5V.6Fe.l9O0,426 (1,08)1851 (564,9)1888 (566,4)37 (ILLUSTRATION)0,426 (1,08)1851 (564,9)1872 (561,6)21 (6,3)16(4,8)

Example

Demonstrative Ti alloy identified as alloy Ti No. 1, having a nominal composition of about 5.0 wt.% aluminum, about 3.0 wt.% vanadium, about 0.6 wt.% iron, about to 0.19 wt.% oxygen and titanium d� 100%, primary mixing together raw materials to achieve the right ratios. A cost analysis on the above-mentioned composition revealed that the cost of the final slab is much less per pound than regular Ti64 alloys resulting from the electron beam remelting. Raw materials received by way of the VEP in the double ingots remelting with a diameter of 6.5 inches (16,51 cm).

The Ti alloy No. 1 was treated in the same way as comparative Ti alloys No. C1-C3. The Ti alloy No. 1 is cast into an ingot of the metal and is converted into an intermediate slab above the temperature beta transus. Rolling and cross rolling then perform a temperature below the beta transus. The final annealing is performed at a temperature below the beta-transus. In this embodiment, the final annealing is performed at 1400°F (760°C) for two hours, and the sample is allowed to cool in air.

Chemical analysis was performed on the destination sheet Ti alloy No. 1, and measured mechanical properties. As found, the Ti alloy No. 1 has a composition of 4.82 wt.% aluminum, of 2.92 wt.% vanadium, and 0.61 wt.% iron, and 0.19 wt.% oxygen and titanium to 100%. As also found, the nitrogen is present in a concentration of 0.001 wt.%. Alloy sheet Ti also had the beta-isomorphous (βiso) stabilizer to beta macroeconomia (βeut) to the stabilizer (βisoeut)1,2, aluminum Al equivalent eq=10,0, molybdenum equivalent Moeq=3,7, the temperature of the beta-transformation Tr=1786°F (974,44°C) and density 0,162 pound per cubic inch (4.48 g/cm3). Elongation properties of the sheet were measured as in cross (Pop.), and longitudinal (Cont.) directions, and perform many measurements on the same sample. The results of these measurements are presented in table 4 below. Elongation properties measured in table 4 are the values of the average WIP=129 kilopound per square inch (9069,6 kg/cm2on average an AV 121 kilopound per square inch (8507,14 kg/cm2), the average ATP=47,5%, and the average elongation of 13%.

Table 4
Summary of tensile properties of Ti alloys No. C1-C3
The nominal composition (wt.%)Elongation properties
OrientationPPP, kilopound per square inch (kg/cm2)AV, kilopound per sqm
inch (kg/cm2)
ATP (%)Elongation (%)
5Al3V0.6Fe0.19 - Cont.129 (9069,6)121 (8507,14)58 14
5Al3V 0.6 Fe About 0.19Cont.130 (9139,91)122 (8577,45)4513
5Al3V0.6Fe0.19 - Pop.128 (8999,29)120 (8436,84)4412
5Al3V0.6Fe0.19 - Pop.129 (9069,6)121 (8507,14)4313

Demonstrative Ti alloy No. 1, having a composition of 4.82 wt.% aluminum, of 2.92 wt.% vanadium, and 0.61 wt.% iron, and 0.19 wt.% oxygen and titanium to 100%, processed with obtaining a sheet having a thickness of about 0,430 inch (1,09 cm). The V50 value for Ti alloy No. 1, as measured, is about 1936 ft/sec (580,8 km/h). This exceeds the minimum 1864 ft/sec (559,2 km/h) set by the U.S. Department of defense for armor plate thickness 0,430 inch (1,09 cm), ΔV50=72 ft/s (21.6 km/h).

Ballistics obtained for comparative Ti alloys No. C1-C3 and Ti alloy No. 1, plotted in Fig.5 and compared with previous results obtained for Ti64 alloys, as disclosed, for example, in the book of Fanning "Ballistic evaluation sheet TIMETAL 6-4 for W�shields from armor-piercing shells" (J. S. Fanning in "Ballistic Evaluation of TIMETAL 6-4 Plate for Protection Against Armor Piercing Projectiles," Proceedings of the Ninth World Conference on Titanium, Vol.II, pp.1172-78 (1999)), which is incorporated by reference as fully as if set out in full in this description. A strong linear correlation between V50and the thickness of the sheet was shown for Ti64 alloys, as shown by the dotted line, which is the best approximation method (R=0,9964) to data on Ti64. The enlarged view of Fig.5, which shows the values of V50obtained for a sheet thickness in the range from 0.40 to 0.46 inches (from 1.02 to 1.12 cm), shown in Fig.6. The data obtained for exponential Ti alloy No. 1 shown as empty triangles in Fig.5-6. While each of comparative Ti alloys No. C1-C3 and Ti alloy No. 1 showed an increase in V50compared with conventional Ti64 alloys of identical thickness, the results in Fig.5-6 show that the largest increase was obtained for Ti alloy No. 1. Thus, exponential Ti alloy No. 1 exceeded the value of Ti64 greater than for all other alloys. He also exceeded the predicted value of V50=1883 ft/sec (564,9 km/h) for Ti64 alloys 53 ft/sec (15,9 km/h), which is a significant margin.

Thus, a typical Ti alloys disclosed in this description, having a composition, in weight percent, essentially of 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium, 0.5 to 0.7% iron and 0.15 and 0.19% of oxygen and titanium to 100%, provide cheap composition, having a mechanical and ballistic properties that are equal with�the normal properties of Ti64 alloys or better than them. Achieved mechanical and ballistic properties exceed military specifications for armour plate class 4 according to the specifications of the Ministry of defense in the "Detailed Specification: Armor plate, Titanium Alloy, Weldable," MIL-DTL-46077G, 2006. Typical Ti alloys disclosed in this description, have the advantage of providing lower cost structure and manufacturing methods of Ti alloys, which are particularly suitable for use as armor plate for military systems.

In the interest of clarity in describing embodiments of the present invention define the following terms, as provided below. All the tensile test was performed according to the standard E8 American societies for testing materials (ASTM E8), whereas the ballistic test was performed in accordance with test methods of the Ministry of defense "Military Standard: Ballistic Testing V50 Armor" M1L-STD-662E, 2006.

The yield strength in tension: Technical tensile stress at which the material shows a maximum deviation of (0.2%) from the proportionality of stress and strain.

The limit tensile strength: maximum tensile stress that a material can withstand calculated from the maximum load during the tensile testing is done�about to break, and the initial cross-sectional area of the test specimen.

The elastic modulus During tensile testing, the ratio of stress to corresponding strain below the limit of proportionality.

Elongation During tensile testing, the increase in the calculated length (expressed as a percentage of the initial reference length) after the cracks.

A decrease in the area: During the tensile tests, reducing the cross sectional area of tie rod test specimen (expressed as a percentage of the initial cross-sectional area after fracture.

Ballistic limit V50: Average speed of a particular type of ammunition that is required for punching sheet alloy having a defined size and installed relative to the point of shooting a certain way. V50calculate the averaged impact velocities, producing full penetration, and shock velocities that produce a partial penetration.

Alpha stabilizer: an Element that, when dissolved in titanium, increases the temperature of the beta-transformation.

Beta stabilizer: an Element that, when dissolved in titanium, reduces the temperature of the beta-transformation.

The temperature of the beta-transformation: the lowest temperature at which the titanium alloy completes allotropical transformation from crystal�cal structure of α+β in the crystalline structure β. This phenomenon is also known as beta-transus.

Eutectoidal connection: an Intermetallic compound of titanium and transition metal, which is produced by decomposition of the β-phase rich in titanium.

Isomorphous beta stabilizer: β-stabilizing element, which has a phase relationship that is similar to the β-titanium, and does not form intermetallic compounds with titanium.

Machidori beta stabilizer: β-stabilizing element that can form intermetallic compounds with titanium.

Specialists in technology understand that the present invention is not limited to what is definitely shown and described above. Rather, the scope of this invention defined by the claims which follows. In addition, it should be understood that the above description is only representative of illustrative examples of embodiments. For the convenience of the reader, the above description has focused on a representative sample of possible embodiments, a sample that teaches the principles of this invention. Other options for implementation may be obtained from various combinations of parts of different variants of implementation.

Description not attempted to exhaustively enumerate all possible variations. What additional implementation options could not be PR�dstanley for a particular part of the invention and can be obtained from various combinations of the described parts, or that other undescribed variants of the implementation can be partially available, should not be deemed a waiver of such additional embodiments. It should be understood that many of those undescribed embodiments are within the precise scope of the following claims of the invention and others are equivalent. Furthermore, all references, publications, U.S. patents and published application for U.S. patent cited in this description, thereby incorporated by reference in their entirety as if they were fully set forth in this description.

All the percentages are weight percentages (wt.%), as in the description and in the claims.

1. Titanium alloy with improved ballistic and mechanical properties, consisting essentially of, in weight percent, of 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium, 0.5 to 0.7% iron, 0.15 to 0.19% of oxygen and titanium to 100%.

2. Titanium alloy according to claim 1, wherein said alloy essentially consists of, in weight percent, about 4.8% aluminum, about 3.0% vanadium, about 0.6% iron, about 0.17% of oxygen and titanium to 100%.

3. Titanium alloy according to claim 1, wherein said alloy has a ratio of beta isomorphous (βiso) stabilizer to beta macroeconomia (βeut) the stabilizer of βisoeutfrom about 0.9 to about 1.7, where βisoeutdefined as

where Mo, V, CR and Fe represent the weight percent of molybdenum, vanadium, chromium and iron in the alloy, respectively.

4. Titanium alloy according to claim 3, wherein said alloy has a ratio of beta isomorphous (βiso) stabilizer to beta macroeconomia (βeut) the stabilizer of βisoeutabout 1.2.

5. Titanium alloy according to claim 1, wherein said alloy has a molybdenum equivalent Moeqfrom about 3.1 to about 4.4, where Moeqdefined as

where Mo, V, CR and Fe represent the weight percent of molybdenum, vanadium, chromium and iron in the alloy, respectively.

6. Titanium alloy according to claim 5, wherein said alloy has a molybdenum equivalent Moeqabout 3.8.

7. Titanium alloy according to claim 1, wherein said aluminum alloy has the equivalent of Aleqfrom about 8.3 to about 10.5, where Aleqdefined as
Aleq=Al+27O,
where Al and O represent the weight percent of aluminum and oxygen in the alloy, respectively.

8. Titanium alloy according to claim 7, wherein said aluminum alloy has the equivalent of Aleqabout 9.4.

9. Titanium alloy according to claim 1, wherein said alloy has a temperature of beta-transformation (Tβ) from about 1732°F (944°C) to about 1820°F (993°C).

10. Titanium alloy according to claim 9, wherein said alloy has a temperature of beta-transformation (Tβ) about 1775°F (968�C).

11. Titanium alloy according to claim 1, wherein the maximum concentration of any one impurity element present in the alloy of titanium, 0.1 wt.%, and the combined concentration of all impurities equal to 0.4 wt.% or less.

12. Titanium alloy according to claim 1, wherein said alloy has a yield strength in tension of at least 120,000 pounds per square inch (about 8440 kg/cm2) and the ultimate tensile strength of at least 128000 psi (about 9000 kg/cm2) in both the longitudinal and transverse directions, and the narrowing of the cross section of at least about 43%, and elongation of at least about 12%.

13. A sheet of titanium alloy, characterized in that it is made of a titanium alloy according to claim 1.

14. A sheet according to claim 13, in which the sheet thickness is from about 0,425 inches to about 0.450 inches (from about 1.08 to about 1.14 cm).

15. A sheet according to claim 14, wherein said sheet has a ballistic limit V50at least about 1848 feet per second (563 km/h).

16. A sheet according to claim 15, wherein said sheet has a thickness of about 0,430 inch (1,09 cm) and the ballistic limit V50approximately 1936 feet per second (590 km/h).

17. The method of producing titanium alloy with improved ballistic and mechanical properties, consisting essentially of, in weight percent, from 4.2 to 5.4% aluminum, 2.5 to 3.5% vanadium,0.5 to 0.7% iron, from 0.15 to 0.19% oxygen and titanium to 100%, including
melting combination of recycled materials containing appropriate amounts of aluminum, vanadium, iron and titanium, in a cold hearth furnace to produce molten alloy; and
spill the specified molten alloy into the mold.

18. A method according to claim 17, in which the reused materials contain shavings Ti64, sponge titanium, iron powder, and the fraction of aluminum.

19. A method according to claim 18, in which the reused materials contain about 70,4% chips Ti64, about 28,0% sponge titanium, about 0.4% of iron powder and about 1.1% of the fraction of aluminum.

20. A method according to claim 17, in which the reused materials contain shavings Ti64, commercially pure titanium waste and developed sponge iron.

21. A method according to claim 17, wherein said molten alloy is poured into a rectangular shape, to obtain a slab having a rectangular shape.

22. A method according to claim 21, further comprising:
exposure initial slab rolling above the temperature of the beta-transformation;
exposure final rolling at a temperature below the beta-transformation;
performing final annealing of the sheet at a temperature below the beta-transformation.

23. A method according to claim 22, in which the final annealing is performed at 1400°F (760°C), and the sheet is allowed to cool to room those�temperature in ambient air.



 

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FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to titanium materials with high strength and processibility. Titanium material contains iron 0.60 wt % or less and oxygen 0.15 wt % or less, titanium and inevitable impurities are the rest. Material has a non-recrystallised structure formed by processing accompanied by plastic deformation and a recrystallised structure formed by annealing after the above treatment; average size of recrystallised α-grains is 1 mcm or more and 5 mcm or less, and surface area of the non-recrystallised part in a cross section of titanium material is more than 0 to 30%.

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FIELD: metallurgy.

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21 cl, 9 dwg, 2 tbl, 6 ex

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9 cl, 2 tbl

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FIELD: metallurgy.

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2 tbl, 1 ex

Titanium material // 2544976

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to titanium materials with high strength and processibility. Titanium material contains iron 0.60 wt % or less and oxygen 0.15 wt % or less, titanium and inevitable impurities are the rest. Material has a non-recrystallised structure formed by processing accompanied by plastic deformation and a recrystallised structure formed by annealing after the above treatment; average size of recrystallised α-grains is 1 mcm or more and 5 mcm or less, and surface area of the non-recrystallised part in a cross section of titanium material is more than 0 to 30%.

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FIELD: process engineering.

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EFFECT: possibility to process hardly deformable titanium under lower temperatures, improved mechanical properties of produced blanks.

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FIELD: medicine.

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2 cl, 1 tbl

FIELD: metallurgy.

SUBSTANCE: proposed process comprises production of the mix of powders, forming the pellet therefrom and execution of self-propagating high-temperature synthesis. Obtained the mix of pure metals containing titanium, aluminium, niobium and molybdenum in the following amount, it wt %: aluminium - 40-44, niobium - 3-5, molybdenum - 0.6-1.4, titanium making the rest. This pellet is compacted to relative density of 50-85% and subjected to thermal vacuum processing at 550-560°C for 10-40 min, heating rate of 5-40°C/ min and pressure of 10-1-10-3 Pa while SPS is performed at initial temperature of 560-650°C.

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2 dwg, 2 tbl, 2 ex

FIELD: metallurgy.

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2 cl, 2 dwg, 4 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: proposed alloy comprises the following elements, in wt %: carbon - 0.03-0.10; iron - 0.15-0.25; silicon - 0.05-0.12; nitrogen - 0.01-0.04; aluminium - 1.8-2.5; zirconium - 2.0-3.0; samarium - 0.5-5.0, titanium and impurities making the rest.

EFFECT: higher efficiency of absorption, better working and bonding properties.

3 tbl, 1 ex

FIELD: metallurgy.

SUBSTANCE: solder contains components at the following ratio in wt %: zirconium - 45-50, beryllium - 2.5-4.5, aluminium - 0.5-1.5, titanium making the rest. Solder represents a flexible band and is produced by super-rapid tempering of the alloy by casting the melt of revolving disc.

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3 cl, 11 dwg, 1 ex

FIELD: mechanical engineering; piston internal combustion engines.

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EFFECT: improved quality of valve and increased reliability in operation.

16 cl, 3 tbl, 1 ex, 15 dwg

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