Machining process for optimizing grain uniformity of titanium material
Patent Information
- Application Number
- CN202510861390.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-25
- Publication Date
- 2025-10-14
AI Technical Summary
[0003]具体来说，针对手机的金属卡托、手机边框这一类产品而言，利用的是钛合金材料的截面，为大众可视面，若晶粒不均，将出现外观异色，固定痕迹等明显影响产品质量的问题
[0023]钛合金原材料经过以上工艺加工处理，材料中晶粒均匀性提高，解决了因晶粒均匀性问题造成产品芯部“白线”问题，提升了产品品质，同时还保证了产品性能。
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of titanium alloy processing, and in particular to a processing technology for optimizing titanium material grain uniformity. Background Art
[0002] Due to varying performance characteristics, raw titanium alloy materials, when used in production, do not meet certain requirements for producing high-end products. For example, when using SLM4 titanium alloy raw materials to produce metal card trays and phone frames for mobile phones, the resulting products exhibit irregular "white lines" and other surface defects, lowering the quality of the product and imperfecting its performance. Therefore, processing of the raw titanium alloy is urgently needed to eliminate these surface defects and improve related performance to a certain extent.
[0003] Specifically, for products such as metal card trays and mobile phone frames for mobile phones, the cross-section of titanium alloy materials is used, which is the visible surface to the public. If the grains are uneven, there will be problems such as discoloration in appearance and fixing marks, which will obviously affect the product quality. Summary of the Invention
[0004] In view of this, the technical problem to be solved by the present invention is to provide a processing technology for optimizing the grain uniformity of titanium materials, thereby improving the grain uniformity of titanium alloy materials and improving product performance through a series of processing treatments.
[0005] In order to solve the above technical problems, the present invention is implemented through the following technical solutions:
[0006] A processing technology for optimizing the uniformity of titanium grains includes the following processes:
[0007] Raw material → wire drawing → annealing 1 → peeling → hot rolling 1 → hot rolling 2 → annealing 2 → hot rolling 3 → hot rolling 4 → annealing 3 → hot rolling 5 → hot rolling 6 → annealing 4 → cold drawing → annealing 5 → cutting → cleaning → quality inspection → packaging.
[0008] Specifically, the raw materials of the present invention are TA4 and TA2 titanium raw materials. The wire drawing step is to use a wire drawing machine to stretch the wire into a regular coil. The annealing operation in each step can improve the mechanical properties of the coil material. The peeling step is to remove the surface defects of the coil by physical methods. The hot rolling operation is to use a mechanical method to roll the titanium alloy material into a flat product at high temperature. The cold drawing step is to make the product a regular flat product and to make its precision size meet customer requirements. The cutting operation is to cut the product into the length required by the client. Quality inspection is to perform an enlarged inspection on the cross section of the processed product.
[0009] In the process, the process conditions of each step are as follows:
[0010] The drawing temperature is 880°C ± 10°C. In this step, the cross-sectional reduction ratio is 2.5%-3%, and the holding time is 6min ± 1min. The function of the wire drawing process is to stretch the titanium alloy raw material into a regular disk, which can improve the uniformity of the grains.
[0011] The temperature of annealing 1 is 920°C ± 10°C. In this step, the holding time is 40min ± 1min. The function of annealing 1 is to improve the mechanical properties of the material and the uniformity of the grains.
[0012] The cross-sectional reduction ratio of the peeling process is 1.5%-2.0%, and the processing line speed is 3.5m / min. The function is to remove defects on the surface of the titanium alloy material.
[0013] The temperature of hot rolling 1 to hot rolling 6 is 1000℃±10℃. The cross-sectional reduction ratio of the material in a single hot rolling in this process is 3.5%-4.5%, and the holding time is 8min±1min. The purpose is to roll the material into a flat wire at high temperature and improve the uniformity of the grains.
[0014] The temperature of annealing 2 to annealing 4 is 920℃±10℃, and the holding time is 35min±1min. The function of this process is to improve the mechanical properties and improve the uniformity of the grains.
[0015] The cross-sectional reduction ratio of the cold drawing process is 0.50%-1%, and the processing line speed is controlled at 1.5m / min. The function is to fine-tune the shape and control the size of the flat wire to meet customer requirements.
[0016] The temperature of annealing step 5 is 920℃±10℃, and the holding time is 30min±1min, which is used to further improve the mechanical properties of the product.
[0017] Subsequent performance tests have shown that the titanium material prepared by the processing technology of the present invention has a yield strength of 500-750 MPa, a tensile strength of 650-850 MPa, an elongation of 15-30%, and a hardness of 220-300 HV.
[0018] The process parameters of each step are shown in Table 1.
[0019] Table 1 Process parameters of each step
[0020]
[0021]
[0022] The beneficial effects of the above technical solution of the present invention are as follows:
[0023] After the titanium alloy raw materials are processed by the above process, the grain uniformity in the material is improved, which solves the "white line" problem in the core of the product caused by grain uniformity, improves product quality, and at the same time ensures product performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 Appearance pictures of titanium materials obtained by the titanium material processing technology of the prior art and Example 1 respectively;
[0025] Figure 2 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 1;
[0026] Figure 3 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 2;
[0027] Figure 4 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 3;
[0028] Figure 5 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 4;
[0029] Figure 6 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 5;
[0030] Figure 7 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 6;
[0031] Figure 8 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 7;
[0032] Figure 9 This is a picture of the appearance of the titanium material produced by the titanium material processing process of Comparative Example 8. DETAILED DESCRIPTION
[0033] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to specific embodiments.
[0034] Titanium alloy materials are very sensitive to temperature. The present invention mainly studies the control of the cross-sectional reduction ratio, the number of hot rolling and annealing, and the sequence of these processes to obtain a titanium alloy processing method that meets the requirements and does not produce "white lines" on the cross section.
[0035] The original titanium processing technology is as follows:
[0036] Raw material → wire drawing → annealing 1 → peeling → hot rolling 1 → hot rolling 2 → hot rolling 3 → hot rolling 4 → cold drawing → annealing 2 → cutting → cleaning → quality inspection → packaging.
[0037] Example 1
[0038] A processing technology for optimizing the uniformity of titanium grains, comprising:
[0039] Raw material → wire drawing → annealing 1 → peeling → hot rolling 1 → hot rolling 2 → annealing 2 → hot rolling 3 → hot rolling 4 → annealing 3 → hot rolling 5 → hot rolling 6 → annealing 4 → cold drawing → annealing 5 → cutting → cleaning → quality inspection → packaging.
[0040] Specifically, the raw material is TA4 type titanium raw material.
[0041] The wire drawing step is to use a wire drawing machine to draw the wire into a regular coil. The wire drawing temperature is 880°C ± 10°C, the cross-sectional reduction ratio during the wire drawing process is 2.5%, and the heat preservation time is 6min ± 1min.
[0042] Each annealing step improves the mechanical properties and grain uniformity of the coiled material. Annealing step 1: The temperature is 920°C ± 10°C, and the hold time is 40 min ± 1 min. Annealing steps 2-4: The temperature is 920°C ± 10°C, and the hold time is 35 min ± 1 min. Annealing step 5: The temperature is 920°C ± 10°C, and the hold time is 30 min ± 1 min.
[0043] The peeling step is to remove surface defects of the disc by physical methods. The cross-sectional reduction ratio of the material after peeling is 1.5%, and the processing line speed is 3.5m / min.
[0044] Hot rolling is a mechanical process that forms titanium alloy materials by high-temperature rolling. The hot rolling temperature is 1000°C ± 10°C, the material cross-sectional reduction is 4.5%, and the holding time is 8 min ± 1 min.
[0045] The cold drawing step is to regularize the product to meet customer specifications. The material cross-sectional reduction ratio in the cold drawing step is 1.0%, and the processing line speed is 1.5m / min.
[0046] The cutting operation is to cut the product into the length required by the customer. The quality inspection is to cut open the cross section of the finished product for inspection.
[0047] The cross-section of the titanium product obtained by the prior art process and Example 1 was opened and tested, and the results were as follows: Figure 1 As shown, Figure 1 As can be seen from Figure B, the core grains of the titanium wire surface product obtained in Example 1 are consistent with the periphery, and there is no appearance defect of "white line".
[0048] Example 2
[0049] The difference between this embodiment and embodiment 1 is that, in the wire drawing step, the cross-sectional reduction ratio is controlled at 2.8%, the peeling cross-sectional reduction ratio is controlled at 1.8%, the cross-sectional reduction ratio of hot rolling 1 to hot rolling 6 is controlled at 4.0%, and the cross-sectional reduction ratio of cold drawing is controlled at 0.8%. The cross section of the titanium product of embodiment 2 is opened and inspected, and there is no appearance defect of "white line".
[0050] Example 3
[0051] The difference between this embodiment and embodiment 1 is that, in the wire drawing step, the cross-sectional reduction ratio is controlled at 3.0%, the peeling cross-sectional reduction ratio is controlled at 2.0%, the cross-sectional reduction ratio of hot rolling 1 to hot rolling 6 is controlled at 3.5%, and the cross-sectional reduction ratio of cold drawing is controlled at 0.5%. The cross section of the titanium product of embodiment 3 is opened and inspected, and there is no appearance defect of "white line".
[0052] Comparative Example 1
[0053] The difference between this comparative example and Example 1 is that the annealing step 2 is omitted and the hot rolling step 3 is directly performed after the hot rolling step 2 is completed, which is equivalent to extending the number and time of continuous hot rolling. The cross section of the titanium product obtained in Comparative Example 1 was cut open and tested, and the results are as follows: Figure 2 As shown. Figure 2 It can be seen that the uniformity of the grains on the surface of the titanium wire product has been improved compared with the existing technology, but there is still a problem of inconsistency between the core grains and the surrounding colors, and there is an appearance defect of "white lines" in the core of the product.
[0054] Comparative Example 2
[0055] The difference between this comparative example and Example 1 is that the annealing step 3 is omitted and the hot rolling step 5 is directly performed after the hot rolling step 4 is completed, which is equivalent to extending the number and time of continuous hot rolling. The cross section of the titanium product obtained in Comparative Example 2 was cut open and tested, and the results are as follows: Figure 3 As shown. Figure 3 It can be seen that the uniformity of the grains on the surface of the titanium wire product has been improved compared with the existing technology, but there is still a problem of inconsistency between the core grains and the surrounding colors, and there is an appearance defect of "white lines" in the core of the product.
[0056] Comparative Example 3
[0057] The difference between this comparative example and Example 1 is that the annealing step 4 is omitted and the temperature is directly lowered to perform the cold drawing operation after the hot rolling 6 is completed. The cross section of the titanium product obtained in Comparative Example 3 was cut open and magnified for inspection. The results are as follows: Figure 4 As shown. Figure 4It can be seen that the uniformity of the grains on the surface of the titanium wire product has been improved compared with the existing technology, but there is still a problem of inconsistency between the core grains and the surrounding colors, and there is an appearance defect of "white lines" in the core of the product.
[0058] Comparative Example 4
[0059] The difference between this comparative example and Example 1 is that the operation of hot rolling 1 or hot rolling 2 is reduced. The cross section of the titanium product obtained in Comparative Example 4 was cut open and tested, and the results are as follows: Figure 5 As shown. Figure 5 It can be seen that the solution of comparative example 4 has improved the uniformity of the grains on the surface of the titanium wire product compared with the prior art, but there is still a problem of inconsistency between the core grains and the surrounding colors, and there is an appearance defect of "white lines" in the core of the product.
[0060] Comparative Example 5
[0061] The difference between this comparative example and Example 1 is that the operation of hot rolling 3 or hot rolling 4 is reduced. The cross section of the titanium product obtained in Comparative Example 5 was cut open and magnified for inspection. The results are as follows: Figure 6 As shown. Figure 6 It can be seen that the solution of Comparative Example 4 does not improve the uniformity of the grains on the surface of the titanium wire product compared to the prior art. At the same time, there is still a problem of inconsistency between the core grains and the surrounding colors, and there is an appearance defect of "white lines" in the core of the product.
[0062] Comparative Example 6
[0063] The difference between this comparative example and Example 1 is that the operation of hot rolling 5 or hot rolling 6 is reduced. The cross section of the titanium product obtained in Comparative Example 6 was cut open and tested, and the results are as follows: Figure 7 As shown. Figure 7 It can be seen that the solution of Comparative Example 6 does not improve the uniformity of the grains on the surface of the titanium wire product compared with the prior art. At the same time, there is still a problem of inconsistency between the core grains and the surrounding colors, and there is an appearance defect of "white lines" in the core of the product.
[0064] Comparative Example 7
[0065] The difference between this comparative example and Example 1 is that the process steps are: raw material → wire drawing → annealing 1 → peeling → hot rolling 1 → annealing 2 → hot rolling 2 → annealing 3 → hot rolling 3 → annealing 4 → hot rolling 4 → annealing 5 → hot rolling 5 → annealing 6 → hot rolling 6 → annealing 7 → cold drawing → annealing 8 → cutting → cleaning → quality inspection → packaging.
[0066] like Figure 8 As shown, although the solution of Comparative Example 7 can solve the "white line" problem in the core of the product, compared with Example 1, Comparative Example 7 performs a total of 8 annealing steps, which is more costly, takes a longer time, and has lower economic benefits.
[0067] Comparative Example 8
[0068] The difference between this comparative example and Example 1 is that the process steps are: raw material → wire drawing → annealing 1 → peeling → hot rolling 1 → annealing 2 → hot rolling 2 → annealing 3 → hot rolling 3 → annealing 4 → cold drawing → annealing 5 → cutting → cleaning → quality inspection → packaging.
[0069] like Figure 9 As shown, the scheme of comparative example 8 has the same number of annealing times as that of embodiment 1, but the annealing step is performed after one hot rolling, the number of hot rolling times is less, and the grain structure is uneven, resulting in the problem that the color of the core grains and the surroundings are still inconsistent, and there is an appearance defect of "white line" in the core of the product.
[0070] Comparative Example 9
[0071] The difference between this comparative example and Example 1 is that the process steps are: raw material → wire drawing → annealing 1 → peeling → hot rolling 1 → hot rolling 2 → hot rolling 3 → annealing 2 → hot rolling 4 → hot rolling 5 → hot rolling 6 → annealing 3 → hot rolling 7 → hot rolling 8 → hot rolling 9 → annealing 4 → cold drawing → annealing 5 → cutting → cleaning → quality inspection → packaging.
[0072] Compared with Example 1, the scheme of Comparative Example 9 has the same number of annealing steps, but the annealing step is performed after three hot rolling steps. Although this can solve the "white line" problem in the core of the product, compared with Example 1, a total of 9 hot rolling steps are performed. The high number of hot rolling steps will lead to grain coarsening, increase residual stress, and affect material strength.
[0073] Comparative Example 10
[0074] The difference between this comparative example and Example 1 is that the temperature of annealing steps 1-5 is 850°C ± 10°C, and the remaining steps are the same as Example 1. Although the "white line" problem in the core of the product can be solved, the product performance is affected, especially the elongation does not meet the production requirements.
[0075] Comparative Example 11
[0076] This comparative example differs from Example 1 in that the annealing temperature in steps 1-5 is 960°C ± 10°C, and the remaining steps are the same as in Example 1. While this solution solves the "white line" problem in the product core, product performance testing reveals that the product is affected, particularly in that the hardness continues to decrease and the elongation initially increases and then decreases, failing to meet production requirements.
[0077] Comparative Example 12
[0078] This comparative example differs from Example 1 in that the holding time in annealing steps 1-5 is reduced by 5 minutes each, and the remaining steps are the same as Example 1. Although this solves the "white line" problem in the product core, product performance testing reveals that the product performance is affected, particularly the elongation, which does not meet production requirements.
[0079] Comparative Example 13
[0080] This comparative example differs from Example 1 in that the holding time in annealing steps 1-5 is increased by 5 minutes each, and the remaining steps are the same as Example 1. Although this solves the "white line" problem in the core of the product, product performance testing reveals that the product performance is affected, particularly the hardness is reduced, and does not meet production requirements.
[0081] Comparative Example 14
[0082] This comparative example differs from Example 1 in that the hot rolling temperature in steps 1-6 is 950°C ± 10°C, and the remaining steps are the same as in Example 1. Although this solves the "white line" problem in the core of the product, product performance testing reveals that the product performance is affected, particularly the elongation is insufficient, and does not meet production requirements.
[0083] Comparative Example 15
[0084] This comparative example differs from Example 1 in that the hot rolling temperature in steps 1-6 is 1050°C ± 10°C, and the remaining steps are the same as in Example 1. Although this solves the "white line" problem in the core of the product, product performance testing reveals that the product performance is affected, particularly with significantly higher elongation and lower hardness, failing to meet production requirements.
[0085] Comparative Example 16
[0086] This comparative example differs from Example 1 in that the holding time for hot rolling steps 1-6 is 13 minutes, and the remaining steps are the same as Example 1. Although this solves the "white line" problem in the product core, product performance testing revealed that the product performance was affected, with yield strength, tensile strength, elongation, and hardness all exceeding the required ranges and failing to meet production requirements.
[0087] Comparative Example 17
[0088] This comparative example differs from Example 1 in that the holding time for hot rolling steps 1-6 is 5 minutes, and the remaining steps are the same as Example 1. Although this solves the "white line" problem in the core of the product, product performance testing reveals that the product performance is affected, especially the elongation is significantly reduced, and does not meet production requirements.
[0089] The performance of the titanium wires of the embodiments and comparative examples was tested using standard methods. The performance test results of each embodiment and comparative example are shown in Table 2.
[0090] Table 2 Performance test results of titanium wire of embodiment and comparative example
[0091]
[0092] From the results shown in Table 2, it can be seen that the present invention aims to solve the "white line" problem of titanium materials, and has high requirements for the number of annealing times, the number of hot rolling times, and the order of annealing and hot rolling in the processing steps. The annealing temperature, annealing holding time, hot rolling temperature, and holding time after hot rolling in the steps are key to ensuring the performance of the titanium material. Therefore, the titanium material processing technology of the present invention improves the grain uniformity of the titanium alloy material and improves the material performance. When the material is used to produce products such as metal card trays and mobile phone frames for mobile phones, irregular "white lines" and other defects in the product appearance can be avoided, thereby improving the quality of the product.
[0093] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A processing technology for optimizing the uniformity of titanium grains, characterized in that: The steps include: Raw material → wire drawing → annealing 1 → peeling → hot rolling 1 → hot rolling 2 → annealing 2 → hot rolling 3 → hot rolling 4 → annealing 3 → hot rolling 5 → hot rolling 6 → annealing 4 → cold drawing → annealing 5; The hot rolling operation is to use a mechanical method to roll the titanium alloy material into a high temperature shape, the hot rolling step temperature is 1000 ° C ± 10 ° C, the material cross-sectional reduction ratio is 3.5%, and the holding time is 8 min ± 1 min; In the annealing step 1, the temperature is 920°C ± 10°C and the holding time is 40 min ± 1 min; In annealing 2, annealing 3, and annealing 4, the temperature is 920°C ± 10°C, and the holding time is 35 min ± 1 min; The temperature in the annealing step 5 is 920°C ± 10°C, and the holding time is 30 min ± 1 min.
2. A processing technology for optimizing the uniformity of titanium grains according to claim 1, characterized in that: The raw materials used are TA4 and TA2 titanium raw materials.
3. The process for optimizing the uniformity of titanium grains according to claim 1, characterized in that: The wire drawing step is to use a wire drawing machine to draw the wire into a regular coil, the wire drawing temperature is 880°C ± 10°C, the cross-sectional reduction ratio during the wire drawing process is 2.5%, and the heat preservation time is 5 minutes to 7 minutes.
4. The process for optimizing the uniformity of titanium grains according to claim 1, characterized in that: The peeling step is to remove the surface defects of the disc by physical methods. The cross-sectional reduction ratio of the material after peeling is 1.5%.
5. A processing technology for optimizing the uniformity of titanium grains according to claim 4, characterized in that: The processing line speed for the peeling step was 3.5 m / min.
6. The process for optimizing the uniformity of titanium grains according to claim 1, characterized in that: The cross-sectional reduction ratio of the material in the cold drawing step is 0.5%.
7. The process for optimizing the uniformity of titanium grains according to claim 6, characterized in that: The processing line speed of the cold drawing step is 1.5 m / min.
8. The process for optimizing the uniformity of titanium grains according to claim 1, characterized in that: It also includes a cutting operation, which is to cut the product into the length required by the client.
9. Titanium flat bar prepared according to the processing technology of any one of claims 1 to 8.
10. Use of the titanium flat bar prepared according to any one of claims 1 to 8 in preparing mobile phone card trays and mobile phone frames.