High-strength, impact-resistant titanium alloy material and manufacturing method thereof

Abstract

wt.% C, balanced titanium, and inevitable impurities; performing a forging process on the titanium alloy casting material to form a titanium alloy forged slab; and performing a rolling process on the titanium alloy forged slab to form a titanium alloy forged plate.

Description

[Technical Field]

[0001] This invention relates to a high-strength, impact-resistant titanium alloy material and its manufacturing method. In particular, but not exclusively, it relates to a high-strength, impact-resistant titanium alloy material and its manufacturing method for use in aerospace, automotive industry, sporting goods and other fields. [Previous Technology]

[0002] In recent years, with the popularization of golf and the improvement of its technical level, golf club heads, due to the nature of the sport, need to strike the hard golf ball at extremely high swing speeds. Furthermore, for performance reasons, the thickness of the striking face is typically between 2 and 4 millimeters. Therefore, the materials used in the club head often need to possess extremely high strength to withstand the harsh impact environment. Consequently, the research and development of golf club materials has become a focus of market attention. Club head materials need to possess excellent strength, toughness, and lightweight properties to cope with the high impact force during the swing and the wear and tear of long-term use. Therefore, choosing the right material is crucial for improving club performance.

[0003] Golf club heads were initially made of stainless steel. However, due to the lightweight and high strength characteristics of titanium alloy castings, titanium alloys (such as Ti-6Al-4V titanium alloy) have been actively developed in recent years to replace stainless steel.

[0004] For example, the prior art discloses a titanium-aluminum alloy for use in golf club heads, comprising 88 wt.% to 92 wt.% titanium and 7.5 wt.% to 10 wt.% aluminum. This titanium-aluminum alloy can also selectively add trace elements such as niobium, vanadium, molybdenum, chromium, iron, silicon, oxygen, and nitrogen to form a high elongation material. This high elongation material is used in the body of the golf club head, combined with a 6Al-4V-Ti titanium alloy striking face with better rigidity to form a golf club head that can achieve a golf club head product with good feel, shock absorption and ball control, and adjustable club angle, allowing for customization.

[0005] Furthermore, the applicant’s previous application, Publication No. TW202100768A, discloses a titanium alloy casting containing 6.5 to 8.5 wt.% aluminum, less than 2.5 wt.% zirconium, less than 2.0 wt.% molybdenum, less than 2.5 wt.% vanadium, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, less than 0.15 wt.% silicon, less than 0.015 wt.% hydrogen, less than 0.15 wt.% oxygen, less than 0.05 wt.% nitrogen, less than 0.08 wt.% carbon, a balanced amount of titanium, and unavoidable impurities.

[0006] However, although the titanium alloy materials of the current technology have been widely used in some fields, there are still several technical problems under certain high performance requirements.

[0007] First, these alloys present a challenge in balancing strength and toughness, especially in high-impact, high-strength, and high-toughness applications (such as the use of golf club heads). They often cannot provide sufficient ductility and toughness while ensuring strength, which can easily lead to embrittlement or fatigue damage of the material.

[0008] Secondly, the performance of existing titanium alloys at high temperatures is not ideal, especially their high-temperature resistance during processing, which easily leads to a decline in alloy properties. This poses a challenge to applications under high-temperature conditions (such as the manufacturing process of golf club heads). Existing materials may not be able to maintain stable mechanical properties after being heat-formed or used for a long time.

[0009] Furthermore, traditional titanium alloys have poor plasticity and machinability during processing, especially when manufacturing complex-shaped parts. The processing of the material is difficult, requiring higher standards for manufacturing processes, which in turn increases costs and manufacturing difficulty. This makes it impossible to achieve efficient production processes for these alloys in actual production.

[0010] In addition, existing titanium alloy materials also have shortcomings in terms of corrosion resistance and fatigue resistance, especially in extreme environments (such as high temperature, high pressure or repeated impact loads), the performance of the materials is prone to decline, which will affect the service life and stability of the final product.

[0011] Finally, although elements such as aluminum, zirconium, vanadium, and molybdenum have played a positive role in improving the performance of titanium alloys, the current alloy composition design has failed to achieve the optimal balance of element ratios. When the aluminum content is too high, the alloy becomes more brittle, which in turn affects its ductility and durability; when the aluminum content is too low, the alloy's strength decreases, resulting in a shorter service life and failing to meet the requirements of high-strength applications.

[0012] Furthermore, it is extremely difficult for titanium alloy materials to surpass the physical properties of existing materials in both strength and elongation.

[0013] Therefore, it is necessary to provide a high-strength, impact-resistant titanium alloy material and its manufacturing method to solve the problems existing in the prior art. [Summary of the Invention]

[0014] To meet these needs, this invention extends the applicant's previous Taiwan Patent Application Publication No. TW202100768A by developing a novel titanium alloy material. Based on the actual application conditions of golf products, the element ratios are more precisely adjusted, resulting in excellent mechanical properties and good heat resistance. Whether cast or rolled, this material exhibits superior quality. Compared to the common Ti-6Al-4V alloy, the material of this invention surpasses it in strength and toughness, and its mechanical properties are not significantly affected even during machining or thermoforming, making it more widely applicable.

[0015] The main objective of this invention is to provide a high-strength, impact-resistant titanium alloy material and its manufacturing method, applicable to casting and sheet metal rolling, capable of producing clubheads of various shapes according to different design requirements. Furthermore, the material's inherent heat resistance makes it suitable for high-temperature environments, maintaining its stability during both processing and final use. This durability ensures the long service life of golf clubs and allows them to perform excellently in various extreme environments.

[0016] In view of the above, the present invention provides a high-strength, impact-resistant titanium alloy material and a method for manufacturing the same. The manufacturing method includes the following steps: providing a titanium alloy casting material, wherein, based on a total weight of 100 wt.% of the titanium alloy casting material, the titanium alloy casting material comprises: 6.5 to 7.0 wt.% aluminum, 2.0 to 2.5 wt.% zirconium, 2.0 to 2.5 wt.% vanadium, 1.0 to 2.0 wt.% molybdenum, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, less than 0.15 wt.% silicon, less than 0.015 wt.% hydrogen, less than 0.15 wt.% oxygen, less than 0.05 wt.% nitrogen, and 0.08 wt.%... The titanium alloy casting material contains less than wt.% carbon, a balanced amount of titanium, and unavoidable impurities; it undergoes a forging process to form a titanium alloy forged slab, wherein the forging process includes: a first forging step, wherein the heating temperature of the first forging step is 1100±20℃; a second forging step, wherein the heating temperature of the second forging step is 950±10℃; a third forging step, wherein the heating temperature of the third forging step is 990±10℃; a fourth forging step, wherein the heating temperature of the fourth forging step is 850±10℃; and a fifth forging step. The process includes: a fifth forging step with a heating temperature of 820±40℃; and a rolling step to form a titanium alloy forged sheet, wherein the rolling step includes: a first rolling step with a heating temperature of 900 to 1100℃; a second rolling step with a heating temperature of 700 to 800℃; a third rolling step with a heating temperature of 900 to 1100℃; and a fourth rolling step with a heating temperature of 700 to 800℃.

[0017] In some embodiments of the present invention, after the first forging step heats the titanium alloy casting material to 1100±20°C, the titanium alloy casting material is subjected to an upsetting and drawing step, and after forging, it is air-cooled to room temperature and the surface cracks are removed by grinding.

[0018] In some embodiments of the present invention, after the second forging step heats the titanium alloy casting material to 950±10°C, the titanium alloy casting material is subjected to a one-upsetting and one-drawing step, and after forging, it is air-cooled to room temperature and the surface cracks are removed by grinding.

[0019] In some embodiments of the present invention, after the third forging step heats the titanium alloy casting material to 990±10°C, the titanium alloy casting material is subjected to a one-upsetting and one-drawing step, and after forging, it is air-cooled to room temperature and the surface cracks are removed by grinding.

[0020] In some embodiments of the present invention, after the fourth forging step heats the titanium alloy casting material to 850±10°C, the titanium alloy casting material is subjected to an upsetting and drawing step, and then reheated in the furnace after forging.

[0021] In some embodiments of the present invention, after the fifth forging step heats the titanium alloy casting material to 820±40°C, the titanium alloy casting material is alternately subjected to unidirectional pressing and four-sided shaping operations to form the titanium alloy forging slab blank.

[0022] In some embodiments of the present invention, the rolling rate of the first rolling step and the second rolling step is 30% to 50%.

[0023] In some embodiments of the present invention, the third hot rolling step includes heating the titanium alloy forged slab to 900 to 1100°C and hot rolling it, controlling the holding time to be 20 to 60 minutes, and performing a water quenching step after the third hot rolling step.

[0024] In some embodiments of the present invention, the fourth rolling step includes heating the titanium alloy forged slab after the third rolling step and the water quenching step to 700 to 800°C and performing reversing rolling, wherein the fourth rolling step is rolled to 70% to 80% of the target plate thickness.

[0025] Furthermore, the present invention also provides a titanium alloy material manufactured by the manufacturing method described above, wherein, based on a total weight of 100 wt.% of the titanium alloy material, the titanium alloy material comprises: 6.5 to 7.0 wt.% aluminum, 2.0 to 2.5 wt.% zirconium, 2.0 to 2.5 wt.% vanadium, 1.0 to 2.0 wt.% molybdenum, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, less than 0.15 wt.% silicon, less than 0.015 wt.% hydrogen, less than 0.15 wt.% oxygen, less than 0.05 wt.% nitrogen, less than 0.08 wt.% carbon, a balance amount of titanium, and unavoidable impurities, wherein the tensile strength of the titanium alloy material is between 139 and 160 KSI, and the yield strength is between 139 and 150 KSI. The KSI value is between 12 and 16%, the elongation is between 35 and 36 HRC, and the durability test results are between 4,000 and 6,000 rounds.

[0026] Beneficial Effects: The titanium alloy material developed in this invention can be applied to casting and plate rolling, enabling the production of club heads of various shapes according to different design requirements. Furthermore, the material's inherent heat resistance makes it suitable for high-temperature environments, maintaining its stability during both processing and final use. This durability ensures the long service life of the golf clubs and allows them to perform excellently in various extreme environments.

[0027] Furthermore, the titanium alloy material of the present invention also possesses excellent plasticity and machinability, making the manufacturing process of the clubhead more efficient, reducing manufacturing costs and improving production efficiency. At the same time, because the material maintains stability at high temperatures, it means that it can maintain consistent performance after multiple processing steps, thereby meeting various design requirements.

[0028] In addition, the titanium alloy material of the present invention can surpass the physical properties of existing titanium alloy materials in both strength and elongation.

[0029] In summary, the titanium alloy material of the present invention not only meets the current market requirements for high-strength, high-toughness, and high-ductility golf clubheads, but also possesses lightweight and good durability, providing a superior solution for golf. With the continuous improvement of market demand, the titanium alloy material of the present invention will show broad application prospects in golf and other high-performance application fields.

Implementation Method

[0030] As used herein, the term "tensile strength" refers to the maximum tensile force a material can withstand during stretching until it breaks or fractures. Tensile strength reflects a material's ability to resist tensile deformation and is commonly used as an indicator of a material's strength properties. The test method involves mounting a cylindrical or rectangular sample on a tensile testing machine and stretching the sample at a fixed speed until it breaks. The maximum load before fracture is measured as the tensile strength. Detailed test methods can be found in ASTM E8 / E8M standards, and tensile testing is performed using a Shimadzu universal testing machine.

[0031] The term "yield strength" as used herein refers to the stress value at which a material, under tensile stress, transitions from elastic deformation to plastic deformation; that is, the stress at which the material begins to undergo permanent deformation and cannot fully recover. The test method is a tensile test, in which a gradually increasing load is applied to the material until the material exhibits significant plastic deformation, and the stress value at that point is recorded as the yield strength. Detailed test methods can be found in ASTM E8 / E8M standards, and tensile tests are performed using a Shimadzu universal testing machine.

[0032] As used herein, the term "elongation" refers to the ratio of the maximum elongation a material can withstand before fracture in a tensile test to its original measured length, usually expressed as a percentage. Elongation reflects the plasticity of a material, indicating the extent to which it can stretch during tension. The test method is a tensile test, in which the maximum elongation of the material from its original length to the point of fracture or permanent deformation under tensile stress is measured, and the ratio to the original length is calculated. Detailed test methods can be found in ASTM E8 / E8M standards, and tensile tests are performed using a Shimadzu universal testing machine.

[0033] As used herein, the term "hardness HRC" refers to the hardness value obtained by measuring the surface of a material using a cone under a specified load, according to the Rockwell hardness measurement method. Specifically, HRC is used to measure the hardness of metallic materials (such as steel) using a Rockwell Type C hardness scale. The hardness is determined by applying a certain load and measuring the depth of the indentation on the material surface. The test method involves using a diamond cone at a 120-degree angle and applying a load of approximately 150 kg. Detailed test methods can be found in ASTM E18 standard.

[0034] The terms "clubhead durability test" or "impact test" used herein refer to high-energy impact testing of materials to simulate impacts or shocks that may be encountered in actual use, and to evaluate the durability and damage characteristics of materials under impact forces. The test method involves hitting a steel ball or other spherical object onto the material surface at a certain speed and angle, and observing the damage to the material surface or structure to test and record cracking, deformation, or other damage phenomena.

[0035] To make the above-mentioned objectives, features and characteristics of the present invention more apparent and understandable, the relevant embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] Figure 1 is a schematic flowchart of a method for manufacturing a high-strength, impact-resistant titanium alloy material according to one embodiment of the present invention. The manufacturing method includes the following steps: providing a titanium alloy casting material, wherein, based on a total weight of 100 wt.% of the titanium alloy casting material, the titanium alloy casting material comprises: 6.5 to 7.0 wt.% aluminum, 2.0 to 2.5 wt.% zirconium, 2.0 to 2.5 wt.% vanadium, 1.0 to 2.0 wt.% molybdenum, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, less than 0.15 wt.% silicon (e.g., greater than 0 wt.% and less than 0.15 wt.%), less than 0.015 wt.% hydrogen (e.g., greater than 0 wt.% and less than 0.015 wt.%), less than 0.15 wt.% oxygen (e.g., greater than 0 wt.% and less than 0.15 wt.%), and less than 0.05 wt.% nitrogen (e.g., greater than 0 wt.% and less than 0.05 wt.%). The titanium alloy casting material contains less than 0.08 wt.% carbon (e.g., greater than 0 wt.% and less than 0.08 wt.%), a balanced amount of titanium, and unavoidable impurities; the titanium alloy casting material is subjected to a forging step to form a titanium alloy forged slab, wherein the forging step includes: a first forging step, wherein the heating temperature of the first forging step is 1100±20℃; a second forging step, wherein the heating temperature of the second forging step is 950±10℃; a third forging step, wherein the heating temperature of the third forging step is 990±10℃; a fourth forging step, wherein the heating temperature of the fourth forging step is 850±10℃; a fifth forging step... The process includes a fifth forging step, wherein the heating temperature of the fifth forging step is 820±40℃; and a rolling step to form a titanium alloy forged sheet, wherein the rolling step includes: a first rolling step, wherein the heating temperature of the first rolling step is 900 to 1100℃; a second rolling step, wherein the heating temperature of the second rolling step is 700 to 800℃; a third rolling step, wherein the heating temperature of the third rolling step is 900 to 1100℃; and a fourth rolling step, wherein the heating temperature of the fourth rolling step is 700 to 800℃.

[0037] The titanium alloy material of the present invention is based on aluminum, zirconium, vanadium and molybdenum, and its performance is enhanced by adding iron and boron. The combination of these components makes the material have a significant improvement in mechanical properties.

[0038] Aluminum (Al) is the main element in the titanium alloy material of the present invention, working synergistically with zirconium (Zr) to improve the alloy's strength and corrosion resistance. The addition of aluminum not only increases strength but also significantly reduces the alloy's density, giving it excellent specific strength, making it suitable for lightweight design applications. Zirconium in this alloy refines the grain size, further enhancing the material's strength while maintaining good ductility. Furthermore, zirconium effectively improves the creep resistance of the titanium alloy in high-temperature environments and strengthens its corrosion resistance, ensuring stability under high temperature and high pressure conditions.

[0039] Vanadium (V) and molybdenum (Mo) further stabilize the β-phase structure of titanium alloys and provide additional strengthening effects. The addition of vanadium not only improves the ductility and plasticity of the alloy, but also makes it exhibit better impact resistance under high dynamic load conditions. Molybdenum, as an effective solid solution strengthening element, significantly improves the high-temperature strength and creep resistance of the alloy, and also enhances the weldability of the material, avoiding cracks during welding and improving the convenience of manufacturing and repair.

[0040] The addition of boron (B) not only promotes the formation of the titanium boron (TiB) phase, significantly improving the strength and hardness of the material, enhancing its wear resistance, and reducing processing defects, but also effectively inhibits grain growth in titanium alloys at high temperatures, which is crucial for maintaining the material's mechanical properties. Especially under high-temperature processing conditions, a fine and uniform grain structure contributes to the material's ductility and creep resistance. Furthermore, trace amounts of iron (Fe) refine the grains, improving the material's plasticity and machinability, making titanium alloys more suitable for processing complex shapes.

[0041] The synergistic effect of these elements enables the titanium alloy to achieve a good balance in terms of strength, ductility, high temperature resistance, corrosion resistance and machinability, making it particularly suitable for industrial applications that require lightweight, high strength and high durability.

[0042] In actual testing, the material of this invention has an advantage over the existing titanium alloy Ti-6Al-4V in casting strength (as shown in Table 1). The addition of trace amounts of boron (B) and iron (Fe) is to further improve the comprehensive performance of the titanium alloy. The presence of boron (B) stabilizes the distribution of the titanium boron (TiB) phase in the alloy, improving the hardness and wear resistance of the material; while the addition of iron (Fe) significantly improves the ductility of the material through grain refinement, and also improves the processing performance, making it suitable for the needs of various complex processes. Therefore, this titanium alloy not only has high strength and good ductility, but also exhibits excellent corrosion resistance and processing adaptability, making it suitable for various high-requirement applications, such as aerospace, automotive industry, sporting goods, and other fields. Table 1. Comparison of casting material properties Material tensile strength TS (KSI) Subjugation strength YS (KSI) elongation EL (%) Hardness (HRC) The casting material of this invention 138 122 9.0 31~33 Ti-6Al-4V casting material 120 107 8.3 26~29

[0043] The titanium alloy material of the present invention is not only excellent in casting, but also, due to its plasticity and thermal stability, when applied to sheet metal production through a specially customized process and heat treatment tempering, exhibits more stable and superior physical properties compared to existing titanium alloy Ti-6Al-4V sheets (as shown in Table 2), making it particularly suitable for the manufacture of golf club heads. Golf club heads are subjected to extremely high impact forces during use, thus placing high demands on the strength, ductility, and fatigue resistance of the material. By applying this titanium alloy to the striking face of the club head, ideal mechanical properties can be achieved, with a tensile strength between 139 and 160 KSI and an elongation between 12 and 16%, effectively resisting deformation under high impact, reducing material weight, and providing design flexibility. These superior properties allow the club head to maintain stability and durability while possessing higher rebound force and hitting effect. It should be noted that the physical properties of the present invention are significantly improved compared to those of the applicant's previously filed Taiwan Patent Application Publication No. TW202100768A, overcoming the difficulty of simultaneously surpassing both strength and elongation. Table 2. Comparison of physical properties between the titanium alloy sheet of the present invention and the Ti-6Al-4V alloy sheet of the prior art. Material tensile strength TS (KSI) Subjugation strength YS (KSI) elongation EL (%) Hardness (HRC) The titanium alloy plate of the present invention 156 145 16 35~36 Ti-6Al-4V substrate 145 120 8.9 31~34

[0044] In terms of heat treatment, the titanium alloy material of the present invention possesses excellent heat resistance, and its mechanical properties are not significantly affected even during machining and heated molding processes. When the titanium alloy sheet of the present invention is heated within the heat treatment temperature range of 500°C to 800°C, the difference in its mechanical properties compared to the original sheet does not exceed 6% (as shown in Table 3), ensuring the stability of the material under various processing and operating conditions. Table 3: Comparison of heat treatment properties of the titanium alloy sheet of the present invention condition tensile strength (KSI) Subjugation strength (KSI) elongation (%) hardness (HRC) original 158.00 141.42 13.24 35-35.5 800℃*1H 151.67 136.13 12.10 33.5-35 750℃*1H 150.20 140.73 12.30 33.5-34.5 600℃*1H 164.63 144.83 13:30 36.5-37.5 500℃*1H 161.23 147.40 12.80 36-37

[0045] Furthermore, based on the extended development material disclosed in the applicant's previous application No. TW202100768A, the present invention has found a more precise optimal ratio of individual components through data accumulation. Specifically, the Al, Zr, and V elements are narrowed down. Taking the data of Examples 2 and 3 as shown in Tables 4 and 5 as examples, when the Al content is between 6.5 and 7 wt.%, the physical properties are most suitable for use on golf hitting surfaces that require high strength and high ductility. The measured clubhead durability limit is optimal. When the Al content continues to increase, it is easy to increase the brittleness of the board and reduce the ductility and durability stability of the material. This will make the durability quality of products made from this material unstable. When the Al content of the material continues to decrease, it will lead to a decrease in strength, which will directly affect the service life of the product. In addition, in order to make it easier to test the durability limit, the clubhead durability test of the present invention uses a thinner hitting surface thickness than that of commercially available products (3.2 mm in the thick area and 2.6 mm in the thin area), and continuously fires golf balls at a fixed ball speed to hit the hitting surface to test the durability strength. Table 4. Al content adjustment test table of the present invention serial number Al Zr V Mo Fe B Example 1 5.38 2.11 2.34 1.25 1.42 0.17 Example 2 6.53 2.15 2.28 1.53 0.72 0.25 Example 3 6.87 2.36 2.14 1.54 1.05 0.22 Example 4 8.25 2.22 2.35 1.78 1.02 0.15 Table 5. Property Table of Al Content Adjustment Test Reference Material of the Invention serial number tensile strength TS (KSI) Subjugation strength YS (KSI) elongation EL (%) Hardness (HRC) Practical clubhead durability test (impact ball speed: 53 m / s) Example 1 128.3 115.5 17.3 27-28.5 2335~3102 Example 2 159.5 142.8 12.7 35-35.5 4533~5770 shots Example 3 157.7 141.7 12.6 35-35.5 4420~5825 shots Example 4 168.5 163.2 7.5 38-39.5 1508~5320

[0046] After determining the optimal Al content, a fixed Al content of 6.5 to 7 wt.% was used, and other components were slightly adjusted for comparison. As shown in Tables 6 and 7, the results indicate that when the Zr and V content is between 2.0 and 2.5 wt.%, suitable physical properties for use in golf club heads are achieved. Adding content below this range can easily lead to insufficient strength, which will also affect the product's strength and lifespan. While excessive addition can further improve material strength, the decrease in elongation will reduce the durability and stability of the product, which is detrimental to the use of golf products. Table 6: Test Table of Component Adjustment in this Invention serial number Al Zr V Mo Fe B Example 2 6.53 2.15 2.28 1.53 0.72 0.25 Example 3 6.87 2.36 2.14 1.54 1.05 0.22 Example 5 6.93 1.53 1.42 1.66 1.15 0.15 Example 6 6.55 2.33 1.21 1.53 1.12 0.15 Example 7 6.78 1.41 2.40 1.24 0.92 0.19 Example 8 7.05 3.22 2.88 1.37 0.88 0.23 Table 7. Property Table of Comparative Tests for Component Adjustment of the Invention serial number tensile strength TS (KSI) Subjugation strength YS (KSI) elongation EL (%) Hardness (HRC) Practical clubhead durability test (impact ball speed: 53 m / s) Example 2 159.5 142.8 12.7 35-35.5 4533~5770 shots Example 3 157.7 141.7 12.6 35-35.5 4420~5825 shots Example 5 137.5 118.6 13.1 32.5-33 1975~2826 Example 6 141.8 127.3 12.5 33.5-34.5 2210~3105 Example 7 142.6 126.7 12.8 33.5-34 2300~3300 rounds Example 8 160.2 143.9 7.9 37-38.5 2295~5750 shots

[0047] Based on the above test results, the inventors designed the composition of the titanium alloy ingot as shown in Table 8. Based on a total weight of 100 wt.% of the titanium alloy material, the titanium alloy material includes: 6.5 to 7.0 wt.% aluminum, 2.0 to 2.5 wt.% zirconium, 2.0 to 2.5 wt.% vanadium, 1.0 to 2.0 wt.% molybdenum, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, less than 0.15 wt.% silicon, less than 0.015 wt.% hydrogen, less than 0.15 wt.% oxygen, less than 0.05 wt.% nitrogen, less than 0.08 wt.% carbon, a balanced amount of titanium, and unavoidable impurities. Table 8, Ingot Composition Design of the Invention Design Components Ti Al Zr V Mo Fe B Ingredient ratio (wt%) Balance 6.5-7.0 2.0-2.5 2.0-2.5 1.0-2.0 0.5-1.5 0.1-0.3

[0048] The advantage of this invention lies in the synergistic effect of its composition design and added elements. By precisely controlling the proportions of aluminum, zirconium, and vanadium, and rationally adding trace amounts of boron, molybdenum, and iron, the material's strength, hardness, ductility, and corrosion resistance are optimally balanced. Furthermore, this material retains excellent plasticity and machinability during processing, making it suitable for large-scale production and application. These performance characteristics make this titanium alloy a promising high-performance material for aerospace, automotive, and sporting goods industries.

[0049] Example manufacturing process of titanium alloy material of the present invention:

[0050] The titanium alloy preparation process of the present invention includes the following steps:

[0051] 1. Ingot casting process

[0052] The raw material configuration includes sponge titanium, aluminum briquettes, aluminum-zirconium alloy, aluminum-molybdenum alloy, aluminum-vanadium alloy, aluminum-iron alloy, and aluminum-boron alloy. The composition includes the following components: 6.5 to 7.0 wt.% aluminum, 2.0 to 2.5 wt.% zirconium, 2.0 to 2.5 wt.% vanadium, 1.0 to 2.0 wt.% molybdenum, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, greater than 0 and less than 0.15 wt.% silicon, greater than 0 and less than 0.015 wt.% hydrogen, greater than 0 and less than 0.15 wt.% oxygen, greater than 0 and less than 0.05 wt.% nitrogen, greater than 0 and less than 0.08 wt.% carbon, a balanced amount of titanium, and unavoidable impurities. The above raw materials are subjected to multiple smelting processes (e.g., by vacuum arc remelting) to form an ingot. The specific steps are as follows:

[0053] After mixing raw materials such as sponge titanium, aluminum granules, and aluminum alloys in the design ratio, the electrodes are pressed.

[0054] The pressing electrode is subjected to vacuum self-consumption melting to form a titanium alloy ingot. The number of melting times can be, for example, 3 times, and the size can be, for example, the diameter of the first ingot is 120±3 mm, the diameter of the second ingot is 170±3 mm, and the diameter of the third ingot is 220±3 mm.

[0055] 2. Ingot processing and inspection

[0056] The surface of the titanium alloy ingot was treated to remove contamination and porosity defects. Then, samples were taken at a distance of, for example, 50 mm from the riser and the bottom of the ingot for chemical composition and gas analysis. The test results showed that all elements met the expected design requirements (as shown in Table 6).

[0057] 3. Forging process

[0058] The titanium alloy ingot is subjected to multiple forging operations to ultimately form a titanium alloy forged slab. The forging process includes:

[0059] In the first forging step, the billet is opened and heated to 1100±20℃. The titanium alloy casting material is subjected to a one-up and one-drawing step. After forging, it is air-cooled to room temperature and the surface cracks are removed by grinding.

[0060] In the second forging step, the billet is reforged and heated to 950±10℃. The titanium alloy casting material is subjected to a one-up and one-drawing step. After forging, it is air-cooled to room temperature and the surface cracks are removed by grinding.

[0061] In the third forging step, the billet is reforged and heated to 990±10℃. The titanium alloy casting material is subjected to a one-up and one-drawing step. After forging, it is air-cooled to room temperature and the surface cracks are removed by grinding.

[0062] In the fourth forging step, the billet is reforged and heated to 850±10℃. The titanium alloy casting material is subjected to a one-up-one-drawing step and then returned to the furnace after forging.

[0063] In the fifth forging step, the heating temperature is 820±40℃. The titanium alloy casting material is subjected to alternating unidirectional pressing and four-sided shaping operations to finally forge a titanium alloy forging slab blank with dimensions of, for example, 400 mm x 300 mm x 60 mm.

[0064] 4. Plate rolling

[0065] After the titanium alloy forged slab (e.g., heated in a high-temperature box-type resistance furnace) is subjected to a four-fire rolling operation, the specific steps of which are as follows:

[0066] The first rolling step is heated at 900 to 1100°C and the rolling rate is 30% to 50%, for example, from a thickness of δ60 mm to a thickness of δ30 mm ± 5 mm;

[0067] The second rolling step is heated to 700 to 800°C and the rolling rate is 30% to 50%, for example, from a thickness of δ30 mm to a thickness of δ15 mm;

[0068] In the third rolling step, the heating temperature is 900 to 1100°C, and the holding time is controlled to be 20 to 60 minutes, followed by a water quenching step;

[0069] The fourth rolling step is heated to 700 to 800°C, and the rolling is reversed to 70% to 80% of the target plate thickness, for example, from a thickness of δ15 mm to a thickness of δ4 ± 0.6 mm.

[0070] The finished titanium alloy sheet has high strength and ductility, and is suitable for applications requiring high strength and lightweight, such as golf club heads, aerospace and automotive industries.

[0071] Furthermore, the present invention also provides a titanium alloy material manufactured by the manufacturing method described above, wherein, based on a total weight of 100 wt.% of the titanium alloy material, the titanium alloy material comprises: 6.5 to 7.0 wt.% aluminum, 2.0 to 2.5 wt.% zirconium, 2.0 to 2.5 wt.% vanadium, 1.0 to 2.0 wt.% molybdenum, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, less than 0.15 wt.% silicon, less than 0.015 wt.% hydrogen, less than 0.15 wt.% oxygen, less than 0.05 wt.% nitrogen, less than 0.08 wt.% carbon, a balanced amount of titanium, and unavoidable impurities, wherein the tensile strength of the titanium alloy material is between 139 and 160 KSI, and the yield strength is between 139 and 150 KSI. The tensile strength of the titanium alloy is between 150 and 160 KSI, the elongation is between 12 and 16%, the hardness is between 35 and 36 HRC, and the durability test is between 4,000 and 6,000 rounds. More preferably, the tensile strength of the titanium alloy is between 150 and 160 KSI, the yield strength is between 142 and 145 KSI, the elongation is between 12 and 13%, the hardness is between 35 and 36 HRC, and the durability test is between 4,000 and 6,000 rounds.

[0072] Figures 2a to 2c show schematic diagrams of the metallographic structure of embodiments of the present invention. The titanium alloy produced by the titanium alloy material composition design and manufacturing method of the present invention has a uniform and fine titanium alloy metallographic structure. Compared with Ti-6Al-4V, the present invention has more strengthening elements such as Mo, Zr, and B, and finds a more precise optimal ratio of individual components through composition design. This gives the material higher strength. However, while the material strength is increased, the elongation is easily reduced. The key to the present invention's ability to achieve high elongation at the same time lies in the forging process. A single heat treatment process involves only one upsetting and drawing (upsetting + drawing), divided into multiple heat treatments to achieve a sufficient number of upsetting and drawing operations. The advantages are that the material grains are finer, the directionality is reduced, and the material defects are reduced. Multiple upsetting and drawing operations break down the strengthening elements formed by the precise optimal ratio of individual component design and distribute them evenly in the material, thereby enabling higher strength while maintaining high elongation.

[0073] The titanium alloy material of this invention was not derived simply through limited experimental adjustments. On the contrary, this design underwent countless experiments and meticulous data analysis, with the proportion of each element precisely adjusted and tested. These processes are far beyond what traditional experiments can easily accomplish; rather, they represent a refined design guided by scientific theory and supported by a wealth of data. Such adjustments not only considered various theoretical deductions but also required repeated verification based on actual conditions to ensure the alloy's performance reached its optimal state. The success of this invention, achieved through countless experiments, is not accidental but a complete breakthrough from existing technological foundations.

[0074] Although this invention is based on and optimizes existing technology, it does not simply involve selective material design, but rather precise adjustments within the existing technological framework. In particular, regarding the proportions of elements such as aluminum, zirconium, and vanadium, this invention breaks through the limitations of traditional titanium alloy design, significantly improving the material's performance in terms of strength, toughness, ductility, high-temperature resistance, and machinability. This improvement is not simply a matter of arbitrarily selecting elements from existing alloys, but rather involves multiple experimental adjustments, determining the most suitable proportions based on rigorous scientific data. Each adjustment is based on meticulous analysis, aiming to achieve an unexpected final effect, enabling the material to maintain excellent mechanical properties even under extreme environments—something that existing technology cannot achieve.

[0075] One of the core advantages of this invention is its unexpected technical effect. Although this invention is an extension of the applicant's previous application publication No. TW202100768A, the alloy composition design and element ratio of this invention achieve a significant breakthrough in performance. Through precise adjustment and corresponding process design and heat treatment conditions, the produced material exhibits stable high strength, high ductility, and durability over a long period under extreme conditions such as high impact and high temperature. Even during repeated processing and heat treatment, the alloy of this invention maintains its unchanged properties, giving it unexpected advantages in application, far exceeding the capabilities of existing technologies. Therefore, this invention not only breaks through the limits of existing technologies but also ensures that it can maintain excellent performance and long-term durability after repeated use and processing.

[0076] Furthermore, the breakthrough in alloy design achieved by this invention was not achieved overnight. Its success stems from the precise control of the proportions of elements such as aluminum, zirconium, and vanadium. The addition and proportion of each component have been confirmed through countless experiments, a process that cannot be easily achieved using traditional experimental methods. It is important to emphasize that the unpredictable effects of this invention do not merely come from the adjustment of a single element, but rather from the synergistic effect between elements, resulting in a holistic optimization of material properties. This process involves not only a large amount of experimental data and adjustments, but also a deep understanding and control of the material's inherent properties.

[0077] In summary, this invention proposes a titanium alloy material with excellent performance. Through a reasonable composition ratio and the synergistic effect of added elements, it achieves high strength, high ductility, and good corrosion resistance, demonstrating a competitive advantage in the market. Its high strength, excellent heat resistance, and outstanding ductility make it irreplaceable in high-strength, high-durability applications. Compared with existing technologies, the material of this invention exhibits more stable performance in extreme environments and can maintain consistent performance over a long period, giving it enormous market potential and competitive advantage in high-performance products such as golf clubs. Especially in applications with extremely high requirements for material performance, the titanium alloy material of this invention demonstrates unexpected technical effects, proving its innovation and breakthrough within the scope of existing technologies. [Simplified Explanation of the Diagram]

[0078] Figure 1 is a schematic flowchart of a method for manufacturing a high-strength, impact-resistant titanium alloy material according to one embodiment of the present invention. Figures 2a to 2c show schematic diagrams of the metallographic structure according to an embodiment of the present invention; wherein Figure 2a is a schematic diagram of the metallographic structure magnified 1000 times by an optical microscope (OM); Figure 2b is a schematic diagram of the metallographic structure magnified 1000 times by a scanning electron microscope (SEM); and Figure 2c is a schematic diagram of the metallographic structure magnified 3000 times by a scanning electron microscope (SEM).

Claims

1. A method for manufacturing a high-strength, impact-resistant titanium alloy material, comprising the following steps: providing a titanium alloy casting material, wherein, based on a total weight of 100 wt.% of the titanium alloy casting material, the titanium alloy casting material comprises: The titanium alloy casting material comprises 6.53 to 7.0 wt.% aluminum, 2.0 to 2.36 wt.% zirconium, 2.0 to 2.28 wt.% vanadium, 1.0 to 2.0 wt.% molybdenum, 0.5 to 1.5 wt.% iron, 0.1 to 0.3 wt.% boron, greater than 0 wt.% and less than 0.15 wt.% silicon, greater than 0 wt.% and less than 0.015 wt.% hydrogen, greater than 0 wt.% and less than 0.15 wt.% oxygen, greater than 0 wt.% and less than 0.05 wt.% nitrogen, greater than 0 wt.% and less than 0.08 wt.% carbon, a balanced amount of titanium, and unavoidable impurities; The titanium alloy casting material is subjected to a forging step to form a titanium alloy forged slab, wherein the forging step includes: The process includes: a first forging step, wherein the heating temperature of the first forging step is 1100±20℃, and the titanium alloy casting material is heated to 1100±20℃ in the first forging step, followed by an upsetting and drawing step; a second forging step, wherein the heating temperature of the second forging step is 950±10℃, and the titanium alloy casting material is heated to 950±10℃ in the second forging step, followed by an upsetting and drawing step; and a third forging step, wherein the heating temperature of the third forging step is 990±10℃, and the titanium alloy casting material is heated to 990±10℃ in the third forging step, followed by an upsetting and drawing step. The process includes: a fourth forging step, wherein the heating temperature of the fourth forging step is 850±10℃, wherein the titanium alloy casting material is heated to 850±10℃ in the fourth forging step and then subjected to an upsetting and drawing step; a fifth forging step, wherein the heating temperature of the fifth forging step is 820±40℃; and a rolling step of the titanium alloy forged slab to form a titanium alloy forged sheet, wherein the rolling step includes: a first rolling step, wherein the heating temperature of the first rolling step is 900 to 1100℃; and a second rolling step, wherein the heating temperature of the second rolling step is 700 to 800℃. A third rolling step, wherein the heating temperature of the third rolling step is 900 to 1100°C; and a fourth rolling step, wherein the heating temperature of the fourth rolling step is 700 to 800°C.

2. The manufacturing method as described in claim 1, wherein the first forging step is followed by air cooling to room temperature and grinding to remove surface cracks.

3. The manufacturing method as claimed in claim 1, wherein the second forging step is followed by air cooling to room temperature and grinding to remove surface cracks.

4. The manufacturing method as claimed in claim 1, wherein the third forging step is followed by air cooling to room temperature and grinding to remove surface cracks.

5. The manufacturing method as claimed in claim 1, wherein the fourth forging step is followed by reheating in the furnace after forging.

6. The manufacturing method as claimed in claim 1, wherein the fifth forging step heats the titanium alloy casting material to 820±40°C, and then alternately performs unidirectional pressing and circumferential shaping operations on the titanium alloy casting material to form the titanium alloy forging slab.

7. The manufacturing method as claimed in claim 1, wherein the rolling ratio of the first rolling step and the second rolling step is 30% to 50%.

8. The manufacturing method as claimed in claim 1, wherein the third hot rolling step includes heating the titanium alloy forged slab to 900 to 1100°C and hot rolling it, controlling the holding time to be 20 to 60 minutes, and performing a water quenching step after the third hot rolling step.

9. The manufacturing method as claimed in claim 8, wherein the fourth hot rolling step includes heating the titanium alloy forged slab after the third hot rolling step and the water quenching step to 700 to 800°C and performing reversing rolling, wherein the fourth hot rolling step rolls to 70% to 80% of the target slab thickness.

10. A titanium alloy material manufactured by the manufacturing method described in any one of claims 1 to 9, wherein the titanium alloy material has a tensile strength between 139 and 160 KSI, a yield strength between 139 and 150 KSI, an elongation between 12 and 16%, and a hardness between 35 and 36 HRC.

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