Method for improving stamping performance of pure titanium sheet

Abstract

The invention provides a method for improving the stamping performance of a pure titanium sheet. The method comprises the following steps that the TA2 pure titanium sheet or the grain size is 1t; a 10-grade TA1 pure titanium thin plate is blanked, and a plate material is obtained; and after oil stains and dust on the surface of the sheet material are removed, the sheet material is vertically placed and subjected to bluing treatment, and the process comprises the steps that the temperature is increased to 500-600 DEG C from the room temperature, heat preservation is conducted for at least 30 min, cooling is conducted, and the treated pure titanium sheet is obtained. The method can improve the stamping performance of the pure titanium sheet.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal thin plate forming, and in particular relates to a method for improving the stamping performance of a pure titanium thin plate. Background Art

[0002] With the development of the application of pure titanium thin plates in the field of daily necessities, higher requirements are placed on the stamping performance of pure titanium thin plates, and most product production processes require multi-pass stamping forming. However, titanium thin plates manufactured by conventional methods often have insufficient ductility and breakage during the multi-pass stamping forming process. The commonly used method is to perform coating lubrication and stress relief annealing, which takes a lot of time and labor costs. Therefore, developing a method to improve the stamping performance of pure titanium thin plates has become a goal pursued by various companies and has received great attention. Summary of the invention

[0003] In view of this, the object of the present invention is to provide a method for improving the stamping performance of pure titanium thin plates, which can improve the stamping performance of ordinary rolled TA1 (grain size <10 grade) or TA2 pure titanium thin plates.

[0004] The present invention provides a method for improving the stamping performance of a pure titanium sheet, comprising the following steps:

[0005] Cutting TA2 pure titanium thin plates or TA1 pure titanium thin plates with a grain size of less than grade 10 to obtain sheet materials;

[0006] After removing the oil and dust from the surface of the sheet, the sheet is placed vertically and subjected to a blueing treatment, the process comprising: heating from room temperature to 500-600° C., keeping the temperature for at least 30 minutes, cooling, and obtaining a treated pure titanium sheet.

[0007] Preferably, the temperature is raised from room temperature to 500-550°C.

[0008] Preferably, the blueing treatment forms a layer containing Ti on the surface of the pure titanium sheet. 6 O and TiO 2 oxide film.

[0009] Preferably, the heating rate from room temperature to 500-600° C. is 10-20° C. / min.

[0010] Preferably, after cooling, the surface is coated with stamping lubricating oil and stamping is performed according to the stamping process.

[0011] Preferably, the grain size of the TA1 pure titanium sheet is grade 8.0.

[0012] Preferably, the thickness of the pure titanium sheet is 0.4-0.5 mm.

[0013] Preferably, the size of the sheet material is a 90 mm×90 mm cup specimen or a 75 mm diameter round specimen.

[0014] Preferably, the atmosphere of the bluing treatment is air.

[0015] The present invention provides a method for improving the stamping performance of a pure titanium sheet, comprising the following steps: cutting a TA2 pure titanium sheet or a TA1 pure titanium sheet with a grain size <10 to obtain a sheet; removing oil and dust from the surface of the sheet, placing it vertically, and performing a blueing treatment, the process comprising: heating from room temperature to 500-600°C, keeping the temperature for at least 30 minutes, cooling, and obtaining a treated pure titanium sheet. The method can improve the stamping performance of a pure titanium sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is an X-ray diffraction measurement diagram of the oxide film produced in Example 1 of the present invention. DETAILED DESCRIPTION

[0017] The present invention provides a method for improving the stamping performance of a pure titanium sheet, comprising the following steps:

[0018] Cutting TA2 pure titanium thin plates or TA1 pure titanium thin plates with a grain size of less than 10 to obtain sheet materials;

[0019] After removing the oil and dust from the surface of the sheet, the sheet is placed vertically and subjected to a blueing treatment, the process comprising: heating from room temperature to 500-600° C., keeping the temperature for at least 30 minutes, cooling, and obtaining a treated pure titanium sheet.

[0020] When pure titanium sheet is heated at high temperature in air, it will react with oxygen to form a dense layer of Ti 6 O and TiO 2 Mixed oxide film. When the temperature rises, the oxide film on the surface of the pure titanium sheet also thickens and interferes with the light, showing different colors; when heated to 500℃~600℃, the color of the oxide layer appears blue. At this time, the oxide film not only protects the titanium surface, but also improves the surface roughness of the titanium plate, especially reduces the difference in surface roughness in the rolling direction and transverse direction of the titanium plate. The oxide film also plays a certain role in lubricant oil storage; and after high-temperature oxidation, the yield strength ratio and elongation of the titanium plate change, thereby effectively improving the stamping performance of the titanium plate.

[0021] In the present invention, the thickness of the TA1 pure titanium thin plate or the TA2 pure titanium thin plate is 0.4-0.5 mm; in a specific embodiment, the thickness of the TA1 pure titanium thin plate is 0.5 mm, and the thickness of the TA2 pure titanium thin plate is 0.4 mm.

[0022] The present invention cuts TA2 pure titanium thin plates or TA1 pure titanium thin plates with a grain size <10 into blank sizes required for part forming, and in the embodiment, a 90mm×90mm cup sample or a 75mm diameter round sample is preferred.

[0023] The present invention preferably uses a cleaning agent ultrasonic cleaning method to remove oil and dust on the surface of the sheet;

[0024] After removing the oil and dust, the present invention is placed vertically on a rack and placed in an oxidation furnace; the vertical placement is to ensure that both sides of the sheet can be oxidized evenly. After being placed in the oxidation furnace, the oxidation furnace starts heating from room temperature to 500-600°C, preferably 500-550°C; the heating rate is 10-20°C / min. In order to ensure uniform oxidation, the temperature is kept at least 30 minutes. The present invention is preferably cooled with the furnace or air-cooled. After the sample is cooled, a layer of Ti-containing 6 O and TiO 2 oxide film.

[0025] The present invention preferably applies stamping lubricating oil on both sides of the surface of the cooled thin plate to achieve the purpose of reducing cracking of the pure titanium thin plate during multi-pass stamping. The stamping lubricating oil used in the present invention is selected from a special stamping lubricating oil for titanium alloys, such as Kozer CUT-312 titanium alloy stretching oil; or L-AN100 oil for full loss system; or a uniform mixture of 95% L-AN46 type lubricating oil as a base agent and 5% castor oil as an oiliness agent; or a uniform mixture of 85% L-AN46 type lubricating oil as a base agent, 5% castor oil as an oiliness agent, and 10% chlorinated paraffin as an extreme pressure agent.

[0026] Cupping performance is one of the important characterization indicators of the stamping performance of pure titanium thin plates. The present invention tests the stamping performance of the pure titanium thin plates prepared by the above method.

[0027] Compared with the prior art, the advantages of the present invention are: (1) the present invention is applicable to TA1 (grain size <10 grade) and TA2 pure titanium thin plates sold on the market with normal rolling process, and has good adaptability; (2) no additional coating and stress relief annealing steps are required during the stamping process; (3) the operation is simple, and the stamping performance of ordinary rolled TA1 (grain size <10 grade) and TA2 pure titanium thin plates can be effectively improved.

[0028] In order to further illustrate the present invention, a method for improving the stamping performance of a pure titanium sheet provided by the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0029] The titanium alloy special stamping lubricant used in the following embodiments is Kozer CUT-312 titanium alloy stretching oil.

[0030] Example 1

[0031] A 0.5 mm TA1 (grain size 8.0 grade) pure titanium sheet purchased from the market was selected, and a 90 mm × 90 mm cupping test specimen was cut. After removing the surface oil and dust from the sheet, 6 sheets were placed vertically in a muffle furnace and heated to 550 ° C at a heating rate of 10 ° C / min for blueing treatment, and then kept warm for 30 minutes and cooled with the furnace. The cupping test was carried out on a BCS-50AR forming test machine, and commercially available titanium alloy special stamping lubricant was used for lubrication. The test parameters were the same, and the mean difference in IE cupping values ​​of 6 TA1 original sheet samples and 6 samples after surface blueing treatment was compared.

[0032] Table 1

[0033] Original board IE cupping value / mm IE cupping value of sample after blueing treatment / mm Cupping value / mm Example 1 10.36 11.53 1.17

[0034] It can be seen from Table 1 that after the TA1 pure titanium sheet in Example 1 was subjected to surface blueing and heat preservation for 30 minutes, its stamping performance was significantly improved, and the average cupping value increased by more than 1 mm.

[0035] Figure 1 is an X-ray diffraction measurement diagram of the oxide film generated in Example 1 of the present invention; Figure 1 It can be seen that the generated oxide film contains Ti 6 O and TiO 2 .

[0036] Example 2

[0037] 0.4mmTA2 pure titanium thin plates purchased from the market were selected to cut 90mm×90mm cupping test specimens. After removing the surface oil and dust from the sheets, 6 sheets were placed vertically in a muffle furnace and heated to 500℃ at a heating rate of 10℃ / min. After keeping warm for 30 minutes, they were air-cooled. The cupping test was carried out on a BCS-50AR forming test machine, and commercially available titanium alloy special stamping lubricant was used for lubrication. The test parameters were the same, and the mean differences in IE cupping values ​​of 6 TA2 original sheet specimens and 6 surface blueing treated specimens were compared.

[0038] Table 2

[0039] Original board IE cupping value / mm IE cupping value of the sample after blueing treatment / mm Cupping value / mm Example 2 5.506 8.083 2.577

[0040] It can be seen from Table 2 that after the TA2 pure titanium sheet in Example 2 was subjected to surface blueing and heat preservation for 30 minutes, its stamping performance was significantly improved, and the average cupping value increased by more than 2 mm.

[0041] Example 3

[0042] 0.5mmTA2 pure titanium thin plates purchased from the market were selected to cut 90mm×90mm cupping test specimens. After removing the surface oil and dust from the sheets, 6 sheets were placed vertically in a muffle furnace and heated to 550℃ at a heating rate of 10℃ / min. After keeping warm for 2 hours, they were air-cooled. The cupping test was carried out on a BCS-50AR forming test machine, and commercially available titanium alloy special stamping lubricant was used for lubrication. The test parameters were the same, and the mean differences in IE cupping values ​​of 6 TA2 original sheet specimens and 6 surface blueing treated specimens were compared.

[0043] Table 3

[0044] Original board IE cupping value / mm IE cupping value of the sample after blueing treatment / mm Cupping value / mm Example 3 8.520 9.572 1.052

[0045] It can be seen from Table 3 that after the TA2 pure titanium sheet in Example 3 was subjected to surface blueing and heat preservation for 2 hours, its stamping performance was significantly improved, and the average cupping value increased by more than 1 mm.

[0046] The thickness of the oxide film formed on the titanium sheet after blueing treatment is about 1.3μm. The average surface roughness of the TA2 original plate sample is Ra=0.236μm, and the average surface roughness of the sample after 550℃ blueing treatment is Ra=0.139μm.

[0047] Example 4

[0048] 0.5mmTA1 (grain size 8.5) pure titanium thin plates purchased from the market were selected to stamp a hat-shaped part (hat-shaped size 50mm). The cutting size was a circular specimen with a diameter of 75mm. After removing surface oil and dust from the specimens, 15 specimens were divided into three groups of 5 (respectively marked as group a, group b and group c) to compare the actual stamping effects. The stamping process parameters remained the same and the same composition lubricant was used.

[0049] The samples in group a were placed in a muffle furnace and heated to 500°C at a heating rate of 10°C / min for bluing treatment. They were kept warm for 30 minutes and cooled in the furnace. The samples after surface bluing treatment were coated with special stamping lubricant for titanium alloy for stamping; the samples in group b were coated with 0.4mm polyethylene film and coated with special stamping lubricant for titanium alloy for stamping; the samples in group c were only stamped with special stamping lubricant for titanium alloy.

[0050] Table 4

[0051] Stamping effect of group a samples Stamping effect of group b samples Stamping effect of group c samples Example 4 All 5 items passed All 5 items passed 1 piece passed, 4 pieces cracked

[0052] As can be seen from Table 4, the stamping effect of the 0.5 mm TA1 (grain size 8.5 grade) pure titanium sheet in Example 4 after surface blueing and heat preservation for 30 minutes is significantly improved compared with the original sheet. Under the same stamping process, the pass rate of 5 stampings of the original sheet coated with lubricant is only 20%; after surface blueing treatment, the pass rate is increased to 100%, and the stamping effect is equivalent to that of coating + coating with commercial titanium alloy special stamping lubricant, and the manual process of tearing the film after stamping is omitted.

[0053] It can be seen from the above embodiments that the present invention provides a method for improving the stamping performance of pure titanium thin plates, comprising the following steps: cutting TA2 pure titanium thin plates or TA1 pure titanium thin plates with a grain size <10 to obtain sheet materials; after removing surface oil and dust from the sheet materials, placing them vertically and performing a bluing treatment, the process includes: heating from room temperature to 500-600°C, keeping the temperature for at least 30 minutes, cooling, and obtaining the treated pure titanium thin plates. This method can improve the stamping performance of pure titanium thin plates. Experimental results show that the average cupping value of the thin plates treated by the method provided by the present invention exceeds 1mm.

[0054] The above is only 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 principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving the stamping performance of pure titanium sheet, comprising the following steps: Cutting TA2 pure titanium thin plates or TA1 pure titanium thin plates with a grain size of less than 10 to obtain sheet materials; After removing the oil and dust from the surface of the sheet, the sheet is placed vertically and subjected to a blueing treatment, the process comprising: heating from room temperature to 500-600° C., keeping the temperature for at least 30 minutes, cooling, and obtaining a treated pure titanium sheet.

2. The method according to claim 1, characterized in that Raise the temperature from room temperature to 500-550°C.

3. The method according to claim 1, characterized in that The bluing treatment forms an oxide film containing Ti6O and TiO2 on the surface of the pure titanium sheet.

4. The method according to claim 1, characterized in that: The heating rate from room temperature to 500-600°C is 10-20°C / min.

5. The method according to claim 1, characterized in that After cooling, the surface is coated with stamping lubricant and stamping is carried out according to the stamping process.

6. The method according to claim 1, characterized in that The grain size of TA1 pure titanium sheet is grade 8.

0.

7. The method according to claim 1, characterized in that The thickness of pure titanium sheet is 0.4 to 0.5 mm.

8. The method according to claim 1, characterized in that The size of the plate is 90mm×90mm cup specimen or 75mm diameter round specimen.

9. The method according to claim 5, characterized in that The atmosphere for the bluing treatment is air.

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