High-strength low-density titanium alloy plate and manufacturing method thereof

Abstract

The invention relates to a titanium alloy plate which comprises the following components in percentage by weight: 7 to 9 percent of aluminum, 0.5 to 2.5 percent of vanadium, 0.5 to 2.5 percent of molybdenum, 0.2 to 1 percent of iron, 0.05 to 0.2 percent of gadolinium, the balance of titanium and inevitable impurities based on the total weight of 100 percent. According to the titanium alloy material disclosed by the invention, a novel titanium alloy plate with high strength and low density is manufactured by adding gadolinium (Gd) and matching with a rolling method.

Description

Technical Field

[0001] The invention relates to a titanium alloy plate and a manufacturing method thereof, and in particular to a high-strength and low-density titanium alloy plate and a manufacturing method thereof. Background Art

[0002] In recent years, the popularity and influence of golf has gradually increased around the world. As golfers become more skilled, the requirements for golf clubs have become more stringent. Among them, the choice of club head material is particularly critical because it directly determines the performance of the club. Golf club heads need to have extremely strong strength and toughness because golfers often swing at very high speeds to hit the golf ball. In addition, the lighter the club head shell, the better, so that there is more weight space to further improve performance.

[0003] Due to the excellent properties of titanium alloy materials, the durability and durability of the club head can be further improved. Unlike traditional iron and stainless steel, titanium alloy will not rust and has excellent corrosion resistance, and can be used for a long time in various harsh environments. Although the commonly used titanium alloy (Ti-8Al-1Mo-1V) in the industry has high strength characteristics, due to industrial competition and the need for continuous innovation, the pursuit of high-strength, low-density and better titanium alloy plates is the direction of the inventor's efforts.

[0004] Therefore, there is a need to provide a high-strength and low-density titanium alloy plate and a manufacturing method thereof to solve the above-mentioned problems. Summary of the invention

[0005] One object of the present invention is to provide a high-strength and low-density titanium alloy plate and a method for manufacturing the same.

[0006] According to the above object, the present invention provides a titanium alloy plate, which comprises the following components, calculated based on the total weight of 100wt%, including 7-9wt% aluminum, 0.5-2.5wt% vanadium, 0.5-2.5wt% molybdenum, 0.2-1wt% iron, 0.05-0.2wt% gadolinium, less than 0.03wt% nitrogen, less than 0.015wt% hydrogen, less than 0.2wt% oxygen, less than 0.05wt% carbon, a balance of titanium, and inevitable impurities.

[0007] Optionally, the titanium alloy plate further comprises the following components: less than 0.03wt% of nitrogen, less than 0.015wt% of hydrogen, less than 0.2wt% of oxygen, and less than 0.05wt% of carbon.

[0008] Optionally, the tensile strength of the titanium alloy plate in the T direction is between 193.3 and 196.4 KSI, and the tensile strength of the titanium alloy plate in the L direction is between 169.5 and 174.5 KSI.

[0009] Optionally, the titanium alloy plate is composed only of the following components: 7-9wt% aluminum, 0.5-2.5wt% vanadium, 0.5-2.5wt% molybdenum, 0.2-1wt% iron, 0.05-0.2wt% gadolinium, less than 0.03wt% nitrogen, less than 0.015wt% hydrogen, less than 0.2wt% oxygen, less than 0.05wt% carbon, a balance of titanium, and unavoidable impurities.

[0010] The present invention further provides a method for manufacturing a titanium alloy plate, comprising the following steps: performing a smelting process on each material containing titanium, aluminum, aluminum, vanadium, molybdenum, iron and gadolinium to form an ingot; performing a forging process on the ingot after spraying an antioxidant to form a plate embryo; and performing a rolling process on the plate embryo sprayed with the antioxidant to form a titanium alloy plate, wherein the rolling process comprises: performing a first hot rolling step: rolling the plate embryo sprayed with the antioxidant at a heating temperature between 1000±100°C to reduce the original thickness of the plate embryo to a first thickness; performing a second hot rolling step: rolling the plate embryo after the first hot rolling step at a heating temperature between 750±50°C to reduce the first thickness of the plate embryo to a second thickness ; performing a third hot rolling step: water quenching the plate blank after the second hot rolling step at a heating temperature between 1000±100°C; and performing a fourth hot rolling step: reversing rolling the plate blank after the third hot rolling step at a heating temperature between 750±50°C to reduce the second thickness of the plate blank to a third thickness; wherein the titanium alloy plate comprises the following components: 7-9wt% aluminum, 0.5-2.5wt% vanadium, 0.5-2.5wt% molybdenum, 0.2-1wt% iron, 0.05-0.2wt% gadolinium, less than 0.03wt% nitrogen, less than 0.015wt% hydrogen, less than 0.2wt% oxygen, less than 0.05wt% carbon, a balance of titanium, and unavoidable impurities.

[0011] The titanium alloy material of the present invention is manufactured into a new type of titanium alloy plate with high strength and low density by adding gadolinium (Gd) and combining with a rolling process. The strength of the titanium alloy plate of the present invention in the T direction is much higher than the strength in the L direction, so the durability of the golf club head made in the T direction is higher than the durability of the golf club head made in the L direction. Furthermore, the titanium alloy plate of the present invention has mechanical properties such as strength that are much higher than those of the commonly used titanium alloy (Ti-8Al-1Mo-1V) in the industry, regardless of whether it is in the L direction or the T direction, and the titanium alloy plate of the present invention has better strength and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The figure is a schematic flow chart of a method for manufacturing a titanium alloy plate according to an embodiment of the present invention.

[0013] Figure 2 It is a schematic diagram of the forging process of the present invention.

[0014] Figure 3 It is a schematic diagram of the rolling process of the present invention.

[0015] Figure 4 This is the metallographic image (scanning electron microscope SEM - 1000 times) of the titanium alloy (Ti-8Al-1Mo-1V) commonly used in the industry.

[0016] Figure 5a This is a metallographic image of the titanium alloy plate of the present invention (optical microscope OM-1000 times).

[0017] Figure 5b This is a metallographic image of the titanium alloy plate of the present invention (scanning electron microscope SEM-1000 times).

[0018] Figure 5c The metallographic image of the titanium alloy plate of the present invention (Scanning electron microscope SEM-3000 times).

[0019] Explanation of symbols in the figure:

[0020] S100 step S200 step

[0021] S210 First forging step S220 Second forging step

[0022] S230 Third forging step S240 Fourth forging step

[0023] S250 step S300 step

[0024] S310 First hot rolling step S320 Second hot rolling step

[0025] S330: third hot rolling step S340: fourth hot rolling step. DETAILED DESCRIPTION

[0026] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0027] Figure 1 The present invention is a schematic flow chart of a method for manufacturing a high-strength, low-density titanium alloy sheet according to an embodiment of the present invention. The method for manufacturing a titanium alloy sheet comprises the following steps:

[0028] In step S100, a smelting process is performed on each material containing titanium (Ti), aluminum (Al), vanadium (V), molybdenum (Mo), iron (Fe) and gadolinium (Gd) to form an ingot. In this embodiment, the smelting process can use sponge titanium, titanium aluminum alloy, metal vanadium particles, molybdenum rods, iron sand and gadolinium oxide for vacuum arc consumable smelting. In another embodiment, the smelting process can also use pure titanium, pure aluminum, pure vanadium, pure molybdenum, pure iron and pure gadolinium for vacuum arc consumable smelting. The vacuum consumable arc refers to the use of a DC power supply to generate an arc between an electrode and a bottom plate placed on a copper crucible. The arc generates a high-heat melting electrode, and the electrode continues to descend and melt, forming a molten pool in a water-cooled copper crucible, and the molten metal completes rapid solidification, crystallization, and ingot formation.

[0029] For example, the smelting process uses sponge titanium, titanium aluminum alloy, molybdenum rod, metal vanadium particles, iron sand and gadolinium oxide as raw materials to configure alloy materials. After each component is proportioned according to the designed quality, it is smelted in a vacuum consumable smelting furnace. The number of smeltings is 3 times, the diameter of the first ingot is 120mm, the diameter of the second ingot is 170mm, and the diameter of the third ingot is 220mm. The ingot production process is as follows: sponge titanium → picking materials → mixing → laying → pressing electrodes → electrode assembly welding → smelting → ingot processing, analysis and inspection → storage. According to the determined process route, alloying method and the formulated trial production plan, an ingot with a diameter of Φ220mm is smelted. After the surface contamination layer and subcutaneous pore defects of the ingot are removed, chemical composition and gas analysis samples are taken at a distance of 50mm from the riser and bottom of the ingot. The standard method is used to complete the composition detection, and the results are shown in Table 1 (the composition ratio of the titanium alloy ingot of the present invention). It can be seen that the main elements and impurity elements in the ingot meet the trial production requirements, and the composition control has achieved the expected goal.

[0030] serial number Ti Al V Mo Fe G N H O C Example 1 bal. 8.06 1.02 1.04 0.249 0.102 ≦0.03 ≦0.015 ≦0.2 ≦0.05 Example 2 bal. 8.12 2.12 0.83 0.240 0.192 ≦0.03 ≦0.015 ≦0.2 ≦0.05 Example 3 bal. 7.96 0.86 1.75 0.570 0.065 ≦0.03 ≦0.015 ≦0.2 ≦0.05 Example 4 bal. 8.25 1.07 2.07 0.285 0.071 ≦0.03 ≦0.015 ≦0.2 ≦0.05 Example 5 bal. 8.05 1.05 0.92 0.490 0.125 ≦0.03 ≦0.015 ≦0.2 ≦0.05 Example 6 bal. 8.12 1.05 1.12 0.501 0.055 ≦0.03 ≦0.015 ≦0.2 ≦0.05 Example 7 bal. 8.03 0.90 2.31 0.284 0.077 ≦0.03 ≦0.015 ≦0.2 ≦0.05 Example 8 bal. 7.98 1.34 1.04 0.305 0.157 ≦0.03 ≦0.015 ≦0.2 ≦0.05

[0031] Table 1

[0032] In step S200, the ingot is sprayed with an antioxidant and then subjected to a forging process to form a slab. For example, the forging equipment used is an 800-ton fast forging machine, and the heating furnace temperature is controlled with an accuracy of ±10°C. Figure 2The forging process of the present invention is a schematic flow chart. The forging process includes: performing a first forging step S210, blanking: at a heating temperature between 1180±20°C, the ingot sprayed with the antioxidant is subjected to an upset and a stretching, air-cooled after forging, and the surface cracks and part of the oxide scale are removed by grinding to form a blank; performing a second forging step S220, re-forging the blank sprayed with the antioxidant: at a heating temperature between 980±10°C, the blank sprayed with the antioxidant after the first forging step S210 is subjected to an upset and a stretching, air-cooled after forging, and the surface cracks and part of the oxide scale are removed by grinding to form a blank; performing a third forging step S230, re-forging the blank sprayed with the antioxidant: at a heating temperature between 980±10°C, the blank sprayed with the antioxidant after the first forging step S210 is subjected to an upset and a stretching, air-cooled after forging, and the surface cracks and part of the oxide scale are removed by grinding to form a blank. At a heating temperature of 960±10°C, the billet sprayed with the antioxidant after the second forging step S220 is subjected to an upset and a stretching process, air-cooled after forging, and surface cracks and part of the oxide scale are removed by grinding; a fourth forging step S240 is performed to re-forge the billet sprayed with the antioxidant: at a heating temperature of 940±10°C, the billet sprayed with the antioxidant after the third forging step S230 is subjected to an upset and a stretching process, and returned to the furnace after forging; and in step S250, the billet after the fourth forging step S240 is subjected to alternating operations of unidirectional pressing and surrounding shaping, and forged into a slab with a size of 400mmx300mmx60mm.

[0033] In step S300, the slab sprayed with the antioxidant is subjected to a rolling process to form a titanium alloy plate. For example, a small plate rolling mill with a roller width of 400 mm is used to complete the plate rolling. The slab is heated by a high-temperature box-type resistance furnace and rolled on a hot rolling test unit rolling mill. A digital potentiometer is used to calibrate the temperature of the box-type resistance furnace to ensure a temperature deviation of ±10°C.

[0034] Figure 3Schematic diagram of the rolling process of the present invention. In this embodiment, the rolling process (i.e., the rolling method) includes: performing a first hot rolling step S310: rolling the slab sprayed with the antioxidant at a heating temperature between 1000±100°C to reduce the original thickness of the slab to a first thickness, for example, δ60mm→δ30mm; performing a second hot rolling step S320: rolling the slab after the first hot rolling step S310 at a heating temperature between 750±50°C to reduce the first thickness of the slab to a second thickness, for example, δ30 mm→δ15mm; perform a third hot rolling step S330: at a heating temperature of 1000±100℃, water quench the slab after the second hot rolling step S320, for example, for 30 minutes; and perform a fourth hot rolling step S340: at a heating temperature of 750±50℃, reverse rolling the slab after the third hot rolling step S330, so that the second thickness of the slab is reduced to the third thickness, for example, δ15mm→δ4±0.6mm, and the finished product needs to be finished after pickling and sandblasting. With the new composition ratio of titanium alloy, the rolling process of the present invention can maintain excellent elongation while having higher strength.

[0035] The titanium alloy plate comprises the following components: 7-9wt% aluminum (Al), 0.5-2.5wt% vanadium (V), 0.5-2.5wt% molybdenum (Mo), 0.2-1wt% iron (Fe), 0.05-0.2wt% gadolinium (Gd), 0.03wt% or less nitrogen (N), 0.015wt% or less hydrogen (H), 0.2wt% or less oxygen (O), 0.05wt% or less carbon (C), a balance of titanium (Ti), and unavoidable impurities, as shown in Table 2 (the composition ratio design of the titanium alloy plate of the present invention). The present invention manufactures a new type of titanium alloy material with higher strength by adding the rare earth element: gadolinium (Gd) and combining it with a rolling process (i.e., a calendering process).

[0036]

[0037] Table 2

[0038] The titanium alloy plate of the present invention adds a small amount of the rare earth element gadolinium (Gd), and uses a special rolling process to make its grains directional, thereby greatly improving the strength of the material in a specific direction, and uses a suitable annealing method to restore the elongation of the material reduced by the rolling process, thereby obtaining a high-strength and high-ductility titanium alloy material, whose physical properties are significantly better than the commonly used titanium alloy (Ti-8Al-1Mo-1V) in the industry.

[0039] According to the titanium alloy plate of the present invention, aluminum (Al) is the main basic element, vanadium (V), molybdenum (Mo) and iron (Fe) are added strengthening elements, and gadolinium (Gd) is an added rare earth element. Rare earth elements have a higher ionic radius and stronger chemical reaction ability, which can change the lattice structure, thereby affecting the performance of the material. The titanium alloy of the present invention uses a small amount of rare earth element gadolinium (Gd) to make the grains more refined. The gadolinium (Gd) element is easily deposited at the grain boundaries of the material, and the gadolinium (Gd) at the grain boundaries of the material during hot rolling will limit and hinder the growth of the grains, so that the treated titanium alloy can finally retain finer grains, thereby improving the physical properties and quality of the material. Figure 4 This is the metallographic diagram of the titanium alloy (Ti-8Al-1Mo-1V) commonly used in the industry, and Figure 5a to Figure 5c This is a metallographic diagram of the titanium alloy plate of the present invention. Figure 5a to Figure 5c It is shown that adding a small amount of gadolinium (Gd) will refine the grains, so finer grains can be obtained in subsequent hot rolling, which is also the key to improving strength.

[0040] In addition, the rolling method used in the titanium alloy sheet of the present invention makes its grains directional, and the striking surface of the golf club head is a force-bearing surface close to an ellipse, so the bearing force and durability will be affected by a specific direction. Therefore, the titanium alloy sheet of the present invention uses a rolling method to deliberately strengthen one of the directions, and applies the direction to the striking surface, thereby achieving the effect of improving strength. Five tensile specimens in the L direction (transverse direction) and the T direction (longitudinal direction) were sampled on a titanium alloy sheet of about 4.5 mm, and a tensile test was performed at room temperature. The test results are shown in Table 3 (physical properties of titanium alloy sheets of various embodiments of the present invention, 5PCS average value). It can be seen from Table 3 that the tensile strength of the titanium alloy sheet in the T direction is between 193.3 and 196.4 KSI, and the tensile strength of the titanium alloy sheet in the L direction is between 169.5 and 174.5 KSI. The strength of the titanium alloy sheet in the T direction of each embodiment of the present invention is much higher than the strength in the L direction, and the durability of the golf club head made in the T direction is higher than the durability of the golf club head made in the L direction.

[0041]

[0042] Table 3

[0043] Taking the physical property comparison of the titanium alloy plate of Example 1 of the present invention and the titanium alloy Ti-8Al-1Mo-1V commonly used in the industry as an example, 5 tensile specimens were sampled in the L direction (transverse direction) and the T direction (longitudinal direction) on the plate of about 4.5 mm, and the tensile test was carried out at room temperature. The test results are shown in Table 4. It can be seen from Table 4 that the titanium alloy plate of Example 1 of the present invention has mechanical properties such as strength far higher than the commonly used titanium alloy (Ti-8Al-1Mo-1V) in the industry in both the L direction and the T direction. When the striking panel of the golf club head is made, the performance will be affected according to the different cutting directions. Cutting the panel in the T direction can ensure that the golf club head has the best mechanical properties.

[0044]

[0045] Table 4

[0046] The advantage of the titanium alloy plate of the present invention is that the strength and ductility of the material are improved while maintaining good processing performance and corrosion resistance. The titanium alloy material of the present invention can be widely used in various occasions requiring high strength and high ductility. Furthermore, the titanium alloy material proposed by the present invention is improved based on the titanium alloy (Ti-8Al-1Mo-1V) commonly used in the industry, and this titanium alloy material has been widely used in the fields of aerospace, automobile and machinery manufacturing. Furthermore, the titanium alloy plate of the present invention is far higher than the titanium alloy (Ti-8Al-1Mo-1V) commonly used in the industry in both the L direction and the T direction, and the titanium alloy plate of the present invention has better strength and durability. Therefore, the titanium alloy material of the present invention can not only improve the performance of existing materials, but also can be further developed and applied on the existing basis.

[0047] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A titanium alloy plate, calculated with its total weight as 100wt%, characterized in that: The titanium alloy plate comprises the following components: 7-9wt% aluminum, 0.5-2.5wt% vanadium, 0.5-2.5wt% molybdenum, 0.2-1wt% iron, 0.05-0.2wt% gadolinium, a balance of titanium, and inevitable impurities.

2. The titanium alloy sheet according to claim 1, characterized in that: The titanium alloy plate also includes the following components: 0.03 wt% or less of nitrogen, 0.015 wt% or less of hydrogen, 0.2 wt% or less of oxygen, and 0.05 wt% or less of carbon.

3. The titanium alloy sheet material according to claim 2, characterized in that: The tensile strength of the titanium alloy plate in the T direction is between 193.3 and 196.4 KSI, and the tensile strength of the titanium alloy plate in the L direction is between 169.5 and 174.5 KSI.

4. A titanium alloy plate, calculated with its total weight as 100wt%, characterized in that: The titanium alloy plate consists only of the following components: 7-9wt% aluminum, 0.5-2.5wt% vanadium, 0.5-2.5wt% molybdenum, 0.2-1wt% iron, 0.05-0.2wt% gadolinium, 0.03 wt% or less of nitrogen, 0.015 wt% or less of hydrogen, 0.2 wt% or less of oxygen, 0.05 wt% or less of carbon, the balance being titanium, and unavoidable impurities.

5. A method for manufacturing a titanium alloy sheet, characterized in that: The following steps are involved: Performing a smelting process on each of the materials including titanium, aluminum, aluminum, vanadium, molybdenum, iron and gadolinium to form an ingot; The ingot is sprayed with an antioxidant and then subjected to a forging process to form a slab; and The plate blank sprayed with the antioxidant is subjected to a rolling process to form a titanium alloy plate, wherein the rolling process comprises: A first hot rolling step is performed: the slab sprayed with the antioxidant is rolled at a heating temperature between 1000±100° C. to reduce the original thickness of the slab to a first thickness; Performing a second hot rolling step: rolling the slab after the first hot rolling step at a heating temperature of 750±50° C. to reduce the first thickness of the slab to a second thickness; Performing a third hot rolling step: water quenching the slab after the second hot rolling step at a heating temperature between 1000±100°C; and A fourth hot rolling step is performed: at a heating temperature of 750±50° C., the slab after the third hot rolling step is subjected to reverse rolling to reduce the second thickness of the slab to a third thickness; The titanium alloy plate comprises the following components: 7-9wt% aluminum, 0.5-2.5wt% vanadium, 0.5-2.5wt% molybdenum, 0.2-1 wt% of iron, 0.05-0.2 wt% of gadolinium, less than 0.03 wt% of nitrogen, less than 0.015 wt% of hydrogen, less than 0.2 wt% of oxygen, less than 0.05 wt% of carbon, the balance of titanium, and unavoidable impurities.

6. The method for manufacturing a titanium alloy sheet material according to claim 5, characterized in that: The smelting process includes: using sponge titanium, titanium aluminum alloy, metal vanadium particles, molybdenum rods, iron sand and gadolinium oxide for vacuum arc consumable smelting.

7. The method for manufacturing a titanium alloy sheet material according to claim 5, characterized in that: The smelting process includes: using pure titanium, pure aluminum, pure vanadium, pure molybdenum, pure iron and pure gadolinium for vacuum arc consumable smelting.

8. The method for manufacturing a titanium alloy sheet material according to claim 5, characterized in that: The forging process includes: A first forging step is performed: the ingot sprayed with the antioxidant is subjected to upsetting and stretching at a heating temperature of 1180±20° C., air-cooled after forging, and surface cracks and part of the oxide scale are removed by grinding to form a billet; A second forging step is performed: at a heating temperature of 980±10° C., the billet sprayed with the antioxidant after the first forging step is subjected to upsetting and drawing, air cooling after forging, and grinding and planing to remove surface cracks and part of the oxide scale; A third forging step is performed: the billet sprayed with the antioxidant after the second forging step is subjected to upsetting and stretching at a heating temperature of 960±10° C., air-cooled after forging, and surface cracks and part of the oxide scale are removed by grinding; Performing a fourth forging step: performing upsetting and stretching of the billet sprayed with the antioxidant after the third forging step at a heating temperature of 940±10° C., and returning to the furnace after forging; and The billet sprayed with the antioxidant after the fourth forging step is subjected to alternating operations of unidirectional pressing and circumferential shaping, and is forged into the slab.

9. The method for manufacturing a titanium alloy sheet material according to claim 5, characterized in that: The tensile strength of the titanium alloy plate in the T direction is between 193.3 and 196.4 KSI, and the tensile strength of the titanium alloy plate in the L direction is between 169.5 and 174.5 KSI.

10. A method for manufacturing a titanium alloy sheet, characterized in that: The following steps are involved: Performing a smelting process on each of the materials including titanium, aluminum, aluminum, vanadium, molybdenum, iron and gadolinium to form an ingot; performing a forging process on the ingot to form a slab; and The plate blank is subjected to a rolling process to form a titanium alloy plate, wherein the rolling process comprises: Performing a first hot rolling step: rolling the slab at a heating temperature between 1000±100° C. to reduce the original thickness of the slab to a first thickness; Performing a second hot rolling step: rolling the slab after the first hot rolling step at a heating temperature of 750±50° C. to reduce the first thickness of the slab to a second thickness; Performing a third hot rolling step: water quenching the slab after the second hot rolling step at a heating temperature between 1000±100°C; and A fourth hot rolling step is performed: at a heating temperature of 750±50° C., the slab after the third hot rolling step is subjected to reverse rolling to reduce the second thickness of the slab to a third thickness; The titanium alloy plate is composed of the following components: 7-9wt% aluminum, 0.5-2.5wt% vanadium, 0.5-2.5wt% molybdenum, 0.2-1wt% iron, 0.05-0.2wt% gadolinium, less than 0.03wt% nitrogen, less than 0.015wt% hydrogen, less than 0.2wt% oxygen, less than 0.05wt% carbon, a balance of titanium, and inevitable impurities.

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