A method for preparing low-cost ti52 titanium alloy ingot from ta15 and tc6 return material

Abstract

The application discloses a method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 return materials, and comprises the following steps: step one, performing electron beam cold hearth furnace smelting on raw materials to obtain primary ingots; the raw materials comprise intermediate alloy, TA15 return material and TC6 return material; step two, performing vacuum consumable arc smelting on the primary ingots, and obtaining Ti52 titanium alloy ingots after cooling. The preparation method combines the advantages and disadvantages of electron beam cold hearth furnace smelting and vacuum consumable arc smelting by taking TA15 return material+TC6 return material+Ti sponge+intermediate alloy as raw materials, and prepares low-cost high-quality Ti52 titanium alloy ingots through double smelting process, so that the phenomenon of uneven chemical composition of Ti52 titanium alloy ingots is avoided, the cost is significantly reduced through the addition of return materials, and the method is suitable for the technical field of titanium alloy ingot preparation.

Description

Technical Field

[0001] This invention belongs to the field of titanium alloy ingot preparation technology, and in particular relates to a method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials. Background Technology

[0002] Titanium alloys possess characteristics such as high specific strength, low density, corrosion resistance, and non-magnetic properties, making them highly valuable in aerospace, weaponry, shipbuilding, and petrochemical industries, with significant potential for further expansion. However, the high cost of raw materials and long processing time of titanium alloys result in a relatively high price compared to metals like steel and aluminum, limiting their wider application. Therefore, cost reduction has become a key research focus and hot topic for titanium alloy researchers in recent years. Two common methods are: (1) replacing expensive elements like V with low-cost elements such as Fe; and (2) reducing raw material costs by adding recycled titanium alloy materials. According to a report by the Russian company Avisma, every 1% increase in recycled titanium materials can reduce the cost of titanium alloy ingots by 0.7%; when the amount of recycled titanium materials added reaches 50%, the cost of titanium alloy ingots can be reduced by at least one-third.

[0003] Recycled titanium alloy materials include ingot risers, ingot bottoms, bar ends, plate edge strips, and machining scrap. During their production, there is a risk of contamination by other raw materials or inclusions, ultimately leading to abnormal ingot composition or the presence of inclusions. Vacuum arc remelting furnaces are one of the most widely used methods for titanium alloy smelting, offering the advantage of producing ingots with good compositional uniformity. However, their impurity removal capabilities are limited due to the simultaneous melting and solidification process. Vacuum electron beam cold hearth furnaces (EB) are another commonly used smelting method. The molten titanium remains on the cold hearth for a period of time, effectively removing inclusions introduced by recycled titanium alloy materials. However, due to the smelting characteristics of electron beam cold hearth furnaces, low-saturation vapor pressure elements (such as Al and Cr) suffer severe loss, making it difficult to control the uniformity of ingot composition.

[0004] Ti52 alloy (nominal composition: Ti-6.7Al-2V-1Zr-1.5Mo-2Cr-0.5Fe) is a titanium alloy grade independently developed and designed in my country. Current technology uses sponge titanium plus an intermediate alloy to produce Ti52 alloy, but this method is costly, and removing inclusions and controlling compositional uniformity in conventional titanium alloy recycled materials is difficult, severely limiting the widespread use of titanium alloys. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing low-cost Ti52 titanium alloy ingots using recycled TA15 and TC6 materials. This method reduces the preparation cost of Ti52 titanium alloy ingots by replacing some raw materials with recycled TA15 and TC6 materials. Furthermore, it combines a dual-melting process of electron beam cold hearth furnace melting and vacuum consumable arc melting to improve the uniformity of the Ti52 titanium alloy ingots, thus producing high-quality Ti52 titanium alloy ingots and solving the problem of high cost in the preparation of Ti52 alloys using existing technologies.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials, characterized in that the method includes the following steps:

[0007] Step 1: Melt the raw materials in an electron beam cold hearth furnace to obtain a primary ingot; the raw materials include intermediate alloy, TA15 recycled material and TC6 recycled material;

[0008] Step 2: The ingot obtained in Step 1 is subjected to vacuum arc melting and cooled to obtain Ti52 titanium alloy ingot.

[0009] The method described above for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials is characterized in that the intermediate alloy in step one is one or more of aluminum-vanadium alloy, aluminum-chromium alloy, ferrotitanium alloy, and aluminum-molybdenum alloy; the particle size of the aluminum-vanadium alloy is 0.83 mm to 3 mm, the particle size of the aluminum-chromium alloy is 1 mm to 3 mm, the particle size of the ferrotitanium alloy is 1 mm to 6 mm, and the particle size of the aluminum-molybdenum alloy is not greater than 0.5 mm.

[0010] The above-mentioned method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials is characterized in that the raw materials in step one further include one or more of sponge titanium, sponge zirconium and aluminum, wherein the sponge titanium is selected from grade 1 or higher sponge titanium.

[0011] The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials described above is characterized in that the total mass of the TA15 recycled material and TC6 recycled material in step one accounts for 60% to 80% of the total mass of the raw materials.

[0012] The above-mentioned method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials is characterized in that, when the TA15 and TC6 recycled materials in step one are in block form, before electron beam cold hearth furnace melting, the TA15 and TC6 recycled materials are acid-washed, alkali-washed, and shot-peened. Then, the raw materials other than the TA15 and TC6 recycled materials are mixed and pressed into electrode blocks. The TA15 recycled materials, TC6 recycled materials, and electrode blocks are layered in the feed box of the electron beam cold hearth furnace as TA15 recycled material layer, TC6 recycled material layer, and electrode block layer. The dimensions of the blocks are: length greater than 100 mm, width greater than 100 mm, and thickness greater than 15 mm.

[0013] This invention, by layering blocky TA15 return material, TC6 return material, and electrode blocks, can control the smooth movement of raw materials during electron beam cold hearth furnace melting, and at the same time, can make the composition of raw materials more uniform during electron beam cold hearth furnace melting, thereby improving the compositional uniformity of the primary ingot.

[0014] The above-mentioned method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials is characterized in that, when the TA15 and TC6 recycled materials in step one are in the form of chips, before electron beam cold hearth furnace melting, the TA15 and TC6 recycled materials are crushed, cleaned, and screened, and then all raw materials are mixed and pressed into electrode blocks; the size of the chips is: length 5mm~12mm, width 5mm~12mm, and thickness not greater than 1mm.

[0015] This invention presses shavings of TA15 and TC6 recycled materials into electrode blocks after mixing them with other raw materials. This avoids the small size of the shavings causing them to scatter during movement in the electron beam cold hearth furnace melting process. At the same time, it can make the composition of raw materials more uniform in the electron beam cold hearth furnace melting process, thereby improving the composition uniformity of the primary ingot.

[0016] The above-mentioned method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials is characterized in that the electron beam cold hearth furnace melting in step one includes a base preparation and a melting process, wherein the electron gun current in the base preparation process is 1A~6A, the melting rate in the melting process is 150kg / h~900kg / h, and the diameter of the crucible in the electron beam cold hearth furnace melting is 300mm~890mm.

[0017] This invention ensures the uniformity of composition in a single casting by controlling the electron gun current during the base-making process and the melting rate during the smelting process.

[0018] The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials is characterized in that the parameters of the vacuum consumable melting in step two are: melting current 8kA~36kA, melting voltage 22V~34V, arc stabilization current 5A~30A, and arc stabilization period 5s~30s; the diameter of the crucible for the vacuum consumable melting is 380mm~1020mm.

[0019] This invention ensures the compositional uniformity of Ti52 titanium alloy ingots by controlling the parameters of vacuum consumable melting; and it allows for the free adjustment of the size of the Ti52 titanium alloy ingots by controlling the crucible diameters of electron beam cold hearth furnace melting and vacuum consumable melting. Furthermore, it ensures that the crucible diameter for electron beam cold hearth furnace melting is smaller than that for vacuum consumable melting, thereby guaranteeing production safety and the surface quality of the ingots.

[0020] The method described above for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials is characterized in that the cross-sectional area ratio of the primary ingot in step one to the Ti52 titanium alloy ingot in step two is 0.62~0.88.

[0021] This invention controls the ratio of the cross-sectional area of ​​a primary ingot to that of a Ti52 titanium alloy ingot to ensure production safety and the surface quality of the ingot.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] 1. This invention reduces the preparation cost of Ti52 titanium alloy ingots by replacing some raw materials with TA15 and TC6 recycled materials. It also avoids uneven chemical composition of Ti52 titanium alloy ingots and improves the quality of Ti52 titanium alloy ingots by combining electron beam cold hearth furnace melting and vacuum consumable arc melting.

[0024] 2. In the raw materials for preparing Ti52 titanium alloy ingots according to the present invention, the total mass ratio of TA15 recycled material and TC6 recycled material can reach more than 60%, which significantly reduces the preparation cost of Ti52 titanium alloy ingots.

[0025] 3. This invention divides TA15 and TC6 return materials into block and chip forms according to size. The block materials are layered with the remaining raw materials to form electrode blocks, which are then melted in an electron beam cold hearth furnace. The chip materials are mixed with the remaining raw materials, pressed into electrode blocks, and then melted in an electron beam cold hearth furnace. By controlling the melting speed of the electron beam cold hearth furnace, the uniformity of the composition of the primary ingot can be effectively controlled. The subsequent vacuum consumable arc melting further ensures the uniformity of the composition of each part of the Ti52 titanium alloy ingot.

[0026] 4. The preparation method of the present invention has a simple process, low production cost, and is easy to industrialize. The diameter of the prepared Ti52 titanium alloy ingot can reach 1020mm. At the same time, the method of preparing low-cost titanium alloys by "returned material of different grades + intermediate alloy" proposed in the present invention is also applicable to the preparation of titanium alloy ingots of other grades.

[0027] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0028] Figure 1 This is a photograph of the Ti52 titanium alloy ingot prepared in Example 1. Detailed Implementation

[0029] Example 1

[0030] In this embodiment, the nominal composition of the Ti52 titanium alloy ingot is Ti-6.0Al-2.6V-1Zr-1.5Mo-1.6Cr-0.5Fe-0.09O. The method for preparing this Ti52 titanium alloy ingot includes the following steps:

[0031] Step 1: 170 kg of aluminum-vanadium alloy with a particle size of 0.83 mm to 3 mm, 115 kg of aluminum-chromium alloy with a particle size of 1 mm to 3 mm, 55 kg of titanium-iron alloy with a particle size of 1 mm to 6 mm, 22 kg of aluminum-molybdenum alloy with a particle size not exceeding 0.5 mm, 46 kg of aluminum pellets, 22 kg of sponge zirconium, and 1580 kg of grade 1 or higher sponge titanium are mixed evenly using an automatic mixing and distribution system and then pressed into 25 blocks with a density of not less than 3.2 g / cm³. 3 Electrode blocks were prepared, and 1400 kg of blocky TA15 return material and 1600 kg of blocky TC6 return material were pickled, alkali-washed, and shot-peened. Then, the electrode blocks, blocky TA15 return material, and blocky TC6 return material were layered in a material box, with one layer of TA15 return material, one layer of TC6 return material, and one layer of electrode blocks, so that they were evenly distributed in the material box for electron beam cold hearth furnace melting to obtain a primary ingot. The dimensions of the blocky TA15 return material and blocky TC6 return material are: length greater than 100 mm, width greater than 100 mm, and thickness greater than 15 mm. The nominal composition of the TA15 return material is Ti-6.5Al-1Mo-1V-2Zr, and the nominal composition of the TC6 return material is Ti-6Al-1.5Cr-2.5Mo-0.5Fe-0.3Si.

[0032] The electron beam cold hearth furnace melting process is as follows: vacuum is drawn to 1.0 × 10⁻⁶. 0Pa is used to prepare the bottom of the crucible. During the bottom preparation process, the electron gun current is maintained at 1A~6A. After the molten metal fills the bottom of the crucible, the melting rate is 700kg / h~900kg / h. After cooling for 10 hours, the crucible is taken out of the furnace. The diameter of the crucible for the electron beam cold hearth furnace melting is 890mm.

[0033] Step 2: The ingot obtained in Step 1 is subjected to vacuum arc melting, cooled for 11 hours, and then removed from the furnace to obtain the following... Figure 1 The 5000kg Ti52 titanium alloy ingot shown; the parameters of the vacuum consumable melting are: melting current 10kA~36kA, melting voltage 27V~34V, arc stabilization current 5A~30A, arc stabilization period 10s~30s; the diameter of the crucible for the vacuum consumable melting is 1020mm.

[0034] The upper, middle and lower parts of the Ti52 titanium alloy ingot prepared in this embodiment were machined and sampled for composition testing. The results are shown in Table 1. The upper part is 200mm~300mm away from the head of the ingot, and the lower part is 200mm~300mm away from the bottom of the ingot.

[0035] Table 1. Mass percentage of components in different parts of the Ti52 titanium alloy ingot prepared in Example 1 (%)

[0036]

[0037] The preparation method of this embodiment was used for repeated preparation and composition analysis. The composition results of each part of the obtained Ti52 titanium alloy ingot are shown in Table 2.

[0038] Table 2. Composition mass percentage of various parts of the Ti52 titanium alloy ingot repeatedly prepared in Example 1 (%)

[0039]

[0040] As shown in Tables 1 and 2, the preparation method of this embodiment can produce Ti52 titanium alloy ingots with uniform overall composition and conform to the nominal composition.

[0041] Example 2

[0042] In this embodiment, the nominal composition of the Ti52 titanium alloy ingot is Ti-6.0Al-2.6V-1Zr-1.5Mo-1.6Cr-0.5Fe-0.10O. The method for preparing this Ti52 titanium alloy ingot includes the following steps:

[0043] Step 1: Mix 10.7 kg of aluminum-vanadium alloy with a particle size of 0.83 mm to 3 mm, 10 kg of aluminum-chromium alloy with a particle size of 1 mm to 3 mm, 4.6 kg of titanium-iron alloy with a particle size of 1 mm to 6 mm, 4.6 kg of aluminum granules, and 90 kg of grade 1 or higher sponge titanium evenly using an automatic mixing and distribution system, and then press them into 15 pieces with a density of not less than 3.2 g / cm³. 3 Electrode blocks were prepared, and 189 kg of blocky TA15 return material and 112 kg of blocky TC6 return material were subjected to acid washing, alkali washing, and shot peening. Then, the electrode blocks, blocky TA15 return material, and blocky TC6 return material were layered in a material box, with one layer of TA15 return material, one layer of TC6 return material, and one layer of electrode blocks, so that they were evenly distributed in the material box for electron beam cold hearth furnace melting to obtain a primary ingot. The dimensions of the blocky TA15 return material and blocky TC6 return material are: length greater than 100 mm, width greater than 100 mm, and thickness greater than 15 mm. The nominal composition of the TA15 return material is Ti-6.5Al-1Mo-1V-2Zr, and the nominal composition of the TC6 return material is Ti-6Al-1.5Cr-2.5Mo-0.5Fe-0.3Si.

[0044] The electron beam cold hearth furnace melting process is as follows: vacuum is drawn to 1.0 × 10⁻⁶. 0 Pa is used to prepare the bottom of the crucible. During the bottom preparation process, the electron gun current is maintained at 1A~6A. After the molten metal fills the bottom of the crucible, the melting rate is 150kg / h~300kg / h. After cooling for 4 hours, the crucible is taken out of the furnace. The diameter of the crucible for the electron beam cold hearth furnace melting is 390mm.

[0045] Step 2: The ingot obtained in Step 1 is subjected to vacuum arc melting, cooled for 5 hours, and then removed from the furnace to obtain a 400kg Ti52 titanium alloy ingot. The parameters of the vacuum arc melting are: melting current 8kA~20kA, melting voltage 22V~30V, arc stabilization current 5A~20A, and arc stabilization period 5s~20s. The diameter of the crucible for the vacuum arc melting is 480mm.

[0046] The upper and lower parts of the Ti52 titanium alloy ingot prepared in this embodiment were machined and sampled for composition testing. The results are shown in Table 3. The upper part is 200mm~300mm away from the head of the ingot, and the lower part is 200mm~300mm away from the bottom of the ingot.

[0047] Table 3. Mass percentage of components in different parts of the Ti52 titanium alloy ingot prepared in Example 2 (%)

[0048]

[0049] As shown in Table 3, the preparation method of this embodiment can produce Ti52 titanium alloy ingots with uniform overall composition and conform to the nominal composition.

[0050] Example 3

[0051] In this embodiment, the nominal composition of the Ti52 titanium alloy ingot is Ti-6.0Al-2.6V-1Zr-1.5Mo-1.6Cr-0.5Fe-0.10O. The method for preparing this Ti52 titanium alloy ingot includes the following steps:

[0052] Step 1: Crush, wash and screen 189kg of shaving TA15 return material and 112kg of shaving TC6 return material to obtain shaving uncontaminated TA15 return material and TC6 return material; the size of the shavings is: length 5mm~12mm, width 5mm~12mm, and thickness not greater than 1mm;

[0053] 11 kg of aluminum-vanadium alloy with a particle size of 0.83 mm to 3 mm, 10.5 kg of aluminum-chromium alloy with a particle size of 1 mm to 3 mm, 5.0 kg of titanium-iron alloy with a particle size of 1 mm to 6 mm, 5.2 kg of aluminum pellets, 105 kg of grade 1 or higher sponge titanium, 205 kg of shavings of non-polluting TA15 recycled material, and 124 kg of shavings of non-polluting TC6 recycled material are mixed evenly by an automatic mixing and distributing system and then pressed into 20 blocks with a density of not less than 3.2 g / cm³. 3 The electrode blocks are then placed into a material box and smelted in an electron beam cold hearth furnace to obtain a primary ingot; the nominal composition of the TA15 return material is Ti-6.5Al-1Mo-1V-2Zr, and the nominal composition of the TC6 return material is Ti-6Al-1.5Cr-2.5Mo-0.5Fe-0.3Si;

[0054] The electron beam cold hearth furnace melting process is as follows: vacuum is drawn to 1.0 × 10⁻⁶. 0 Pa is used to prepare the bottom of the crucible. During the bottom preparation process, the electron gun current is maintained at 1A~6A. After the molten metal fills the bottom of the crucible, the melting rate is 150kg / h~250kg / h. After cooling for 4 hours, the crucible is taken out of the furnace. The diameter of the crucible for melting in the electron beam cold hearth furnace is 300mm.

[0055] Step 2: The ingot obtained in Step 1 is subjected to vacuum arc melting, cooled for 5 hours, and then removed from the furnace to obtain a 460kg Ti52 titanium alloy ingot. The parameters of the vacuum arc melting are: melting current 8kA~15kA, melting voltage 22V~30V, arc stabilization current 5A~20A, and arc stabilization period 5s~20s. The diameter of the crucible for the vacuum arc melting is 380mm.

[0056] The upper and lower parts of the Ti52 titanium alloy ingot prepared in this embodiment were machined and sampled for composition testing. The results are shown in Table 4. The upper part is 200mm~300mm away from the head of the ingot, and the lower part is 200mm~300mm away from the bottom of the ingot.

[0057] Table 4. Mass percentage of components in different parts of the Ti52 titanium alloy ingot prepared in Example 3 (%)

[0058]

[0059] As shown in Table 4, the preparation method of this embodiment can produce Ti52 titanium alloy ingots with uniform overall composition and conform to the nominal composition.

[0060] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials, characterized in that, The method includes the following steps: Step 1: The raw materials are smelted in an electron beam cold hearth furnace to obtain a primary ingot. The raw materials include intermediate alloy, TA15 recycled material, and TC6 recycled material. The electron beam cold hearth furnace smelting includes a base preparation and a smelting process. The electron gun current in the base preparation process is 1A~6A, and the melting rate in the smelting process is 150kg / h~900kg / h. When the TA15 recycled material and TC6 recycled material are in block form, before electron beam cold hearth furnace smelting, the TA15 recycled material and TC6 recycled material are acid-washed, alkali-washed, and shot-peened. Then, the raw materials other than the TA15 recycled material and TC6 recycled material are mixed and pressed into electrode blocks. The TA15 recycled material, TC6 recycled material, and electrode blocks are layered in the feed box of the electron beam cold hearth furnace as TA15 recycled material layer, TC6 recycled material layer, and electrode block layer. When the TA15 and TC6 recycled materials are in shavings, before electron beam cold hearth furnace melting, the TA15 and TC6 recycled materials are crushed, washed, and screened, and then all raw materials are mixed and pressed into electrode blocks; the total mass of the TA15 and TC6 recycled materials accounts for 60% to 80% of the total mass of the raw materials. Step 2: The ingot obtained in Step 1 is subjected to vacuum arc melting and cooled to obtain Ti52 titanium alloy ingot.

2. The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials according to claim 1, characterized in that, The intermediate alloy mentioned in step one is one or more of aluminum-vanadium alloy, aluminum-chromium alloy, ferrotitanium alloy, and aluminum-molybdenum alloy; the particle size of the aluminum-vanadium alloy is 0.83mm~3mm, the particle size of the aluminum-chromium alloy is 1mm~3mm, the particle size of the ferrotitanium alloy is 1mm~6mm, and the particle size of the aluminum-molybdenum alloy is no greater than 0.5mm.

3. The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials according to claim 1, characterized in that, The raw materials mentioned in step one also include one or more of sponge titanium, sponge zirconium and aluminum, wherein the sponge titanium is selected as grade 1 or above.

4. The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials according to claim 1, characterized in that, The dimensions of the block mentioned in step one are: length greater than 100mm, width greater than 100mm, and thickness greater than 15mm.

5. The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials according to claim 1, characterized in that, The dimensions of the shavings mentioned in step one are: length 5mm~12mm, width 5mm~12mm, and thickness not greater than 1mm.

6. The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials according to claim 1, characterized in that, The diameter of the crucible used in the electron beam cold hearth furnace melting in step one is 300mm~890mm.

7. The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials according to claim 1, characterized in that, The parameters for vacuum consumable melting in step two are: melting current 8kA~36kA, melting voltage 22V~34V, arc stabilization current 5A~30A, and arc stabilization period 5s~30s; the diameter of the crucible for vacuum consumable melting is 380mm~1020mm.

8. The method for preparing low-cost Ti52 titanium alloy ingots from TA15 and TC6 recycled materials according to claim 1, characterized in that, The ratio of the cross-sectional area of ​​the primary ingot in step one to that of the Ti52 titanium alloy ingot in step two is 0.62 to 0.88.

Images