Preparation method of titanium alloy Y profile

Abstract

The invention discloses a preparation method of a titanium alloy Y profile, which comprises the following steps: proportioning and selecting glass powder components according to an extrusion temperature, and the glass powder components comprise 3-30% of SiO2, 30-70% of B2O3, 3-8% of Al2O3, 2-5% of MgO, 3-20% of CaO, 3-5% of Na2CO3, 3-20% of Na2O, 2-20% of K2O and 1-8% of TiO2; the glass pad is melted in order, so that the lubricating effect is improved; an extrusion container, an extrusion grinding tool and a glass pad are fully preheated to improve the softening speed of the glass pad and reduce the temperature drop speed of a blank, so that the extrusion process is smoothly carried out; and hot withdrawal straightening and cold withdrawal straightening are combined, so that the straightening effect is effectively improved. The titanium alloy Y profile prepared through the method is good in straightness, the surface of the titanium alloy Y profile has silver metal luster after acid pickling, defects such as longitudinal grooves and pits are not found on the surface, the dimensional tolerance is within a reasonable range, and the use requirements of users can be met.

Description

Technical Field

[0001] The invention belongs to the technical field of alloy materials, and particularly relates to a method for preparing a titanium alloy Y-shaped profile. Background Art

[0002] Titanium alloy has high specific strength, deep hardenability and good corrosion resistance. It has been widely used in the aerospace field. It is the main load-bearing structural material for the heat-resistant parts of the rear fuselage of my country's large aircraft. It can be used for the center beam of the horizontal tail, wing fuselage fairing, engine suspension / nacelle, nose reinforcement, crossbeam, support parts, etc.

[0003] Although titanium alloys have been widely used in the aerospace field, due to the inherent characteristics of titanium alloys, there are still major problems in the processing of complex titanium alloy structural parts. There are still many technical difficulties in preparing products that meet the performance requirements of titanium alloys for aviation. As an asymmetric structure profile, the titanium alloy Y profile has mainly rolling and extrusion processes. The extrusion process is flexible in production, large billet deformation, and excellent performance. However, due to the large extrusion deformation, complex use of lubricants, and immature extrusion technology, the spherical flat titanium obtained by extrusion has problems such as surface cracking, insufficient end filling, and large plate size deviation.

[0004] Common lubrication methods for titanium alloy extrusion profiles include grease lubrication, metal sheathing and glass lubrication. Grease lubrication is suitable for small batches and short-size profile preparation; metal sheathing has a complex process, subsequent surface treatment is difficult, and the yield rate is low; glass lubrication is an ideal lubrication method for titanium alloy profile preparation. In addition to being affected by its inherent properties of softening temperature, high temperature viscosity, wettability and elastic modulus, it is also affected by the use conditions, so it has high requirements for the composition ratio of the lubricant and the extrusion process. At present, the straightness of extruded titanium alloy profiles is often improved by straightening, and the surface quality is improved by shot blasting, grinding and pickling. Summary of the invention

[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention prepares a titanium alloy Y profile that meets dimensional tolerance, straightness and good surface quality on the basis of ensuring the basic performance of the titanium alloy Y profile.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides a method for preparing a titanium alloy Y-shaped profile, the method comprising the following steps:

[0007] ① Extrusion billet preparation: the titanium alloy bar billet prepared by forging is machined, the billet is turned into φ255×200~500mm extrusion billet, and the end face is chamfered, with the chamfer R10~R50.

[0008] ② After blending water glass solution (Na2SiO3·9H2O) and water (H2O) in a mass ratio of 7:3, the mixture is mixed with glass powder in a mass ratio of 1:4 and pressed into a glass mat; the main components of the glass powder are SiO2: 3-30%, B2O3: 30-70%, Al2O3: 3-8%, MgO: 2-5%, CaO: 3-20%, Na2CO3: 3-5%, Na2O: 3-20%, K2O: 2-20%, and TiO2: 1-8%.

[0009] In the process of preparing the glass powder components, the component ratio is selected according to the extrusion temperature so that the softening temperature and the flow temperature of the glass powder should match the extrusion temperature.

[0010] During the preparation of the glass mat, the thickness of the glass mat is controlled to be about 15 mm and the diameter is 255 mm. At the same time, the glass mat is kept as soft as possible to facilitate orderly melting of the glass mat and improve the lubrication effect.

[0011] ③ Spray glass paint on the extruded billet, the mass percentage of the main components of the glass paint is SiO2: 5-30%, B2O3: 15-70%, Na2CO3: 3-5%, Na2O: 3-20%, H2O: 3-70%; preheat the extruded billet in a heating furnace, the preheating temperature is 100°C-350°C, the preheating time is 5-30min, and after preheating, use a spray gun to spray the paint, and the paint spraying thickness is 0.3-2.0mm.

[0012] During the glass coating spraying process, the coating needs to be stirred evenly before use. To ensure the coating thickness, a spray gun needs to be used for multiple sprayings. During the transportation of the blank, the coating needs to be prevented from falling off.

[0013] ④ Heat the electric furnace to 650℃~800℃, put the blank after spraying the coating obtained in step ③ into it, keep it warm for 20~120min, then continue to heat it to 900℃~1100℃, and continue to keep it warm for 30~150min.

[0014] During the heating process in the electric furnace, the surface anti-oxidation coating is prevented from falling off during the billet transfer and heating process.

[0015] ⑤ Preheat the extrusion cylinder, extrusion mold and glass pad at 300℃~500℃ for 20~60min.

[0016] The extrusion cylinder, extrusion mold and glass pad are fully preheated to increase the softening speed of the glass pad and reduce the temperature drop rate of the blank, which is conducive to the smooth progress of the extrusion process.

[0017] ⑥ Extruding the billet on a 45MN horizontal extruder, first put the glass mat into the extrusion barrel, and then apply a lubricant with a mass ratio of 5:4:1 of engine oil: flake graphite: molybdenum disulfide to the inner wall of the extrusion barrel. After the extruded billet is taken out of the furnace, it is rolled on the roller coating powder for 1 to 2 circles. The composition of the roller coating powder used is consistent with the glass powder composition used for the glass mat. Then the extruded billet is placed in the extrusion barrel for extrusion, with an extrusion ratio of 8 to 30 and an extrusion rate of 50 to 250 mm / s.

[0018] ⑦ Straighten the extruded titanium alloy Y profile. First, perform hot drawing straightening. Fix the two ends of the Y profile on the clamping end of the straightening machine and use electric heating to heat up. The heating rate is 50-100℃ / min, the straightening temperature is 550℃-750℃, and the straightening stretching amount is 3-8%; then perform cold drawing straightening with a straightening stretching amount of 1-3%.

[0019] In the straightening process, hot drawing and cold drawing are combined to effectively improve the straightening effect.

[0020] ⑧ Pickle the straightened Y-profile in a pickling tank with an acid concentration (volume ratio) of HF:HNO3:H2O=1:4:15 for 5 to 10 minutes. After pickling, wash it in warm water at 50°C to 70°C for 5 minutes to obtain a titanium alloy Y-profile.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This technical solution selects the ratio of glass powder components according to the extrusion temperature, so that the softening temperature and flow temperature of the glass powder match the extrusion temperature; the glass pad is melted in an orderly manner to improve the lubrication effect; the extrusion cylinder, extrusion mold and glass pad are fully preheated to increase the softening speed of the glass pad and reduce the temperature drop rate of the blank, which is conducive to the smooth extrusion process; hot straightening and cold straightening are combined to effectively improve the straightening effect. The titanium alloy Y profile prepared by this method has good straightness, and the surface presents a silvery-white metallic luster after pickling. No defects such as longitudinal grooves and pits are found on the surface. The dimensional tolerance is within a reasonable range and can meet the user's usage needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the titanium alloy Y-profile mold of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with specific examples, but the present invention is not limited in any way. To avoid redundant description, the raw materials in the following examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods unless otherwise specified.

[0025] A method for preparing a titanium alloy Y-shaped profile (the structural schematic diagram of the titanium alloy Y-shaped profile mold is as shown in Figure 1 As shown), the method comprises the following steps:

[0026] ① Process the titanium alloy bar into an extrusion billet of φ255×200~500mm, and chamfer the end surface to R10~R50;

[0027] ② Mix water glass and water in a mass ratio of 7:3, then mix with glass powder and press into a glass mat;

[0028] ③ Preheating the extruded billet in a heating furnace at a temperature of 100° C. to 350° C. for 5 to 30 minutes, and spraying the billet with glass paint after preheating at a thickness of 0.3 to 2.0 mm;

[0029] ④ Heat the electric furnace to 650℃~800℃, put the blank after spraying the coating obtained in step ③, keep it warm for 20~120min, then continue to heat it to 900℃~1100℃, and keep it warm for 30~150min;

[0030] ⑤ Preheat the extrusion cylinder, extrusion mold and glass pad at 300℃~500℃ for 20~60min;

[0031] ⑥ Place the glass mat into the extrusion barrel, and apply lubricant to the inner wall of the extrusion barrel; after the extruded billet is taken out of the furnace, roll it on the roller coating powder for 1 to 2 circles, and then place the extruded billet into the extrusion barrel for extrusion, with an extrusion ratio of 8 to 30 and an extrusion rate of 50 to 250 mm / s;

[0032] ⑦ Straighten the extruded titanium alloy Y profile. First, perform hot drawing straightening. Fix both ends of the Y profile on the clamping end of the straightening machine and use electric heating to heat it up. The heating rate is 50-100℃ / min, the straightening temperature is 550℃-750℃, and the straightening stretching amount is 3-8%; then perform cold drawing straightening with a straightening stretching amount of 1-3%;

[0033] ⑧ Pickle the straightened Y profile in a pickling tank with an acid concentration of HF:HNO3:H2O=1:4:15 for 5 to 10 minutes. After pickling, wash in warm water at 50°C to 70°C for 5 minutes.

[0034] The matters not described in the following embodiments are the same as the description of the above specific implementation methods.

[0035] Example 1

[0036] A method for preparing a titanium alloy Y-shaped profile, the specific process flow is as follows:

[0037] ① Extrusion billet preparation: the titanium alloy bar blank prepared by forging is machined, the billet is turned into a φ255×200mm extrusion billet, and the end face is chamfered, with the chamfer R10.

[0038] ② Preparation of glass mat: the glass powder composition is SiO2: 3%, B2O3: 70%, Al2O3: 3%, MgO: 5%, TiO2: 1%, CaO: 10%, Na2CO3: 3%, Na2O: 3%, K2O: 2%. Mix water glass and water in a ratio of 7:3 and mix with the glass powder and press into a glass mat.

[0039] ③ Spray glass paint on the blank, the mass percentage of the glass paint components is SiO2: 20%, B2O3: 20%, Na2CO3: 3%, Na2O: 3%, H2O: 54%; preheat the blank in a heating furnace, the preheating temperature is 200℃, the preheating time is 15min, and then use a spray gun to spray the paint, and the paint spraying thickness is 0.5mm.

[0040] ④ Heat the electric furnace to 650°C, put in the blank after spraying the coating obtained in step ③, keep it warm for 30 minutes, then continue to heat it to 950°C, and continue to keep it warm for 60 minutes.

[0041] ⑤ Preheat the extrusion cylinder, extrusion mold and glass pad at 300℃ for 30min. The extrusion mold is rounded R15 at the entrance and the guide groove is processed at the end to increase the uniformity of metal flow during extrusion.

[0042] ⑥ Extrusion of the billet on a 45MN horizontal extruder. First, place the glass mat into the extrusion barrel, and then apply lubricant with a mass ratio of 5:4:1 of engine oil: flake graphite: molybdenum disulfide to the inner wall of the extrusion barrel. After the extruded billet is taken out of the furnace, roll it on the roller coating powder for 2 circles, and then put the extruded billet into the extrusion barrel for extrusion, with an extrusion ratio of 14 and an extrusion rate of 50mm / s.

[0043] ⑦ Straighten the extruded titanium alloy Y profile. First, perform hot drawing straightening. Fix the two ends of the Y profile on the clamping end of the straightening machine and use electric heating to heat up. The heating rate is 50℃ / min, the straightening temperature is 550℃, and the straightening stretching amount is 3%; then perform cold drawing straightening with a straightening stretching amount of 3%.

[0044] ⑧ Pickle the straightened Y profile in a pickling tank with an acid concentration (volume ratio) of HF:HNO3:H2O=1:4:15 and a pickling time of 5 minutes. After pickling, wash in warm water at 50°C for 5 minutes.

[0045] The surface of the titanium alloy Y-profile prepared in Example 1 has a metallic luster and good flatness, and no obvious surface defects are found.

[0046] Example 2

[0047] A method for preparing a titanium alloy Y-shaped profile, the specific process flow is as follows:

[0048] ① Process the titanium alloy bar into an extruded billet of φ255×200mm, and chamfer the end surface to R10.

[0049] ② Preparation of glass mat: the chemical composition of glass powder is SiO2: 3%, B2O3: 70%, Al2O3: 3%, MgO: 5%, TiO2: 1%, CaO: 10%, Na2CO3: 3%, Na2O: 3%, K2O: 2%. Mix water glass and water in a ratio of 9:1 and mix with glass powder and press to make glass mat.

[0050] ③ Heat the electric furnace to 650℃, put in the unpainted blank, keep it warm for 30 minutes, then continue to heat it to 950℃, and continue to keep it warm for 60 minutes.

[0051] ④ Preheat the extrusion cylinder, extrusion mold and glass pad at 300℃ for 30 minutes.

[0052] ⑤ Extrusion of the billet on a 45MN horizontal extruder. First, place the glass mat into the extrusion barrel, and then apply lubricant with a mass ratio of 5:4:1 of engine oil: flake graphite: molybdenum disulfide to the inner wall of the extrusion barrel. After the extruded billet is taken out of the furnace, roll it on the roller coating powder for 2 circles, and then put the extruded billet into the extrusion barrel for extrusion, with an extrusion ratio of 14 and an extrusion rate of 50mm / s.

[0053] ⑥ Straighten the extruded titanium alloy Y profile, first perform hot drawing straightening, fix the two ends of the Y profile on the clamping end of the straightening machine, use electric heating to heat up, the heating rate is 50℃ / min, the straightening temperature is 550℃, and the straightening stretching amount is 3%. Then perform cold drawing straightening, the straightening stretching amount is 3%.

[0054] ⑦ Pickle the straightened Y profile in a pickling tank with an acid concentration (volume ratio) of HF:HNO3:H2O=1:4:15 and a pickling time of 5 minutes. After pickling, wash it in warm water at 50°C for 5 minutes.

[0055] Example 2 Description: When no surface coating is used, the prepared titanium alloy Y-profile has good straightness, but obvious small pits and longitudinal groove defects appear on the surface.

[0056] Example 3

[0057] A method for preparing a titanium alloy Y-shaped profile, the specific process flow is as follows:

[0058] ① Process the titanium alloy bar into an extruded billet of φ255×500mm, and chamfer the end surface to R50.

[0059] ② Preparation of glass mat: the glass powder composition is SiO2: 3%, B2O3: 70%, Al2O3: 3%, MgO: 5%, TiO2: 1%, CaO: 10%, Na2CO3: 3%, Na2O: 3%, K2O: 2%. Mix water glass and water in a ratio of 9:1 and mix with the glass powder and press into a glass mat.

[0060] ③ Spray glass paint on the blank, the mass percentage of the glass paint components is SiO2: 20%, B2O3: 20%, Na2CO3: 3%, Na2O: 3%, H2O: 54%; preheat the blank in a heating furnace, the preheating temperature is 200℃, the preheating time is 15min, and then use a spray gun to spray the paint, the paint spraying thickness is 0.5mm.

[0061] ④ Heat the electric furnace to 650°C, put in the blank after spraying the coating obtained in step ③, keep it warm for 30 minutes, then continue to heat it to 850°C, and continue to keep it warm for 60 minutes.

[0062] ⑤ Preheat the extrusion cylinder, extrusion mold and glass pad at 300℃ for 30 minutes.

[0063] ⑥ Extrusion of the billet on a 45MN horizontal extruder. First, place the glass mat into the extrusion barrel, and then apply lubricant with a mass ratio of 5:4:1 of engine oil: flake graphite: molybdenum disulfide to the inner wall of the extrusion barrel. After the extruded billet is taken out of the furnace, it is rolled on the roller coating powder for 2 circles, and then the extruded billet is placed in the extrusion barrel for extrusion, with an extrusion ratio of 14 and an extrusion rate of 50mm / s.

[0064] ⑦ Straighten the extruded titanium alloy Y profile. First, perform hot drawing straightening. Fix the two ends of the Y profile on the clamping end of the straightening machine and use electric heating to heat up. The heating rate is 50℃ / min, the straightening temperature is 550℃, and the straightening stretching amount is 3%; then perform cold drawing straightening with a straightening stretching amount of 3%.

[0065] ⑧ Pickle the straightened Y profile in a pickling tank with an acid concentration of HF:HNO3:H2O=1:4:15 for 5 minutes. After pickling, wash it in warm water at 50°C for 5 minutes.

[0066] Example 3 shows that when the heating temperature of the extruded billet is lowered, the straightness of the prepared titanium alloy Y-profile is good, but serious longitudinal groove defects appear on the surface.

[0067] Example 4

[0068] A method for preparing a titanium alloy Y-shaped profile, the specific process flow is as follows:

[0069] ① Process the titanium alloy bar into an extruded billet of φ255×400mm, and chamfer the end surface to R10.

[0070] ② Preparation of glass mat: the glass powder composition is SiO2: 3%, B2O3: 70%, Al2O3: 3%, MgO: 5%, TiO2: 1%, CaO: 10%, Na2CO3: 3%, Na2O: 3%, K2O: 2%. Mix water glass and water in a ratio of 9:1 and mix with the glass powder and press into a glass mat.

[0071] ③ Spray glass paint on the blank, the mass percentage of the glass paint components is SiO2: 20%, B2O3: 20%, Na2CO3: 3%, Na2O: 3%, H2O: 54%; preheat the blank in a heating furnace, the preheating temperature is 200℃, the preheating time is 15min, and then use a spray gun to spray the paint, the paint spraying thickness is 0.5mm.

[0072] ④ Heat the electric furnace to 650°C, put in the blank after spraying the coating obtained in step ③, keep it warm for 30 minutes, then continue to heat it to 950°C, and continue to keep it warm for 60 minutes.

[0073] ⑤ Preheat the extrusion cylinder, extrusion mold and glass pad at 300℃ for 30 minutes.

[0074] ⑥ Extrude the billet on a 45MN horizontal extruder. First, put the glass mat into the extrusion barrel, and then apply a lubricant with a ratio of 5:4:1 of engine oil: flake graphite: molybdenum disulfide to the inner wall of the extrusion barrel; after the extruded billet comes out of the furnace, roll it on the roller coating powder for 2 circles, and then put the extruded billet into the extrusion barrel for extrusion, with an extrusion ratio of 14 and an extrusion rate of 50 mm / s.

[0075] ⑦ Straighten the extruded titanium alloy Y profile by first performing hot drawing straightening. Fix both ends of the Y profile on the clamping end of the straightening machine and use electric heating to heat it up. The heating rate is 50℃ / min, the straightening temperature is 550℃, and the straightening stretching amount is 3%.

[0076] ⑧ Pickle the straightened Y profile in a pickling tank with an acid concentration of HF:HNO3:H2O=1:4:15 for 5 minutes. After pickling, wash it in warm water at 50°C for 5 minutes.

[0077] Example 4 Description: When cold straightening at room temperature is not used, the surface of the prepared titanium alloy Y-profile has a metallic luster, no obvious surface defects are found, but a slight lateral bending phenomenon occurs.

[0078] For any technician familiar with the art, without departing from the scope of the technical solution of the present invention, the technical content disclosed above can be used to make many possible changes and modifications to the technical solution of the present invention, or modified into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention should still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A method for preparing a titanium alloy Y-shaped profile, characterized in that: The method comprises the following steps: ① Process the titanium alloy bar into an extrusion billet of φ255×200~500mm, and chamfer the end surface to R10~R50; ② Mix water glass and water in a mass ratio of 7:3, mix with glass powder and press into a glass mat; ③ Preheating the extruded billet in a heating furnace at a temperature of 100° C. to 350° C. for 5 to 30 minutes, and spraying the glass coating with a coating thickness of 0.3 to 2.0 mm after preheating; ④ Heat the electric furnace to 650℃~800℃, put the blank after spraying the coating obtained in step ③, keep it warm for 20~120min, then continue to heat it to 900℃~1100℃, and keep it warm for 30~150min; ⑤ Preheat the extrusion cylinder, extrusion mold and glass pad at 300℃~500℃ for 20~60min; ⑥ Place the glass mat into the extrusion barrel, and apply lubricant to the inner wall of the extrusion barrel; after the extruded billet is taken out of the furnace, roll it on the roller coating powder for 1 to 2 circles, and then place the extruded billet into the extrusion barrel for extrusion, with an extrusion ratio of 8 to 30 and an extrusion rate of 50 to 250 mm / s; ⑦ Straighten the extruded titanium alloy Y profile. First, perform hot drawing straightening. Fix both ends of the Y profile on the clamping end of the straightening machine and use electric heating to heat it up. The heating rate is 50-100℃ / min, the straightening temperature is 550℃-750℃, and the straightening stretching amount is 3-8%; then perform cold drawing straightening with a straightening stretching amount of 1-3%; ⑧ Pickle the straightened Y profile in a pickling tank with an acid concentration of HF:HNO3:H2O=1:4:15 for 5 to 10 minutes. After pickling, wash in warm water at 50°C to 70°C for 5 minutes.

2. The preparation method according to claim 1, characterized in that: In step ②, the glass powder has the following components in percentage by weight: SiO2: 3-30%, B2O3: 30-70%, Al2O3: 3-8%, MgO: 2-5%, CaO: 3-20%, Na2CO3: 3-5%, Na2O: 3-20%, K2O: 2-20%, and TiO2: 1-8%.

3. The preparation method according to claim 1, characterized in that: In step ②, the thickness of the glass mat is controlled to be 14-16 mm.

4. The preparation method according to claim 1, characterized in that: Step ③ The glass coating composition comprises SiO2: 5-30%, B2O3: 15-70%, Na2CO3: 3-5%, Na2O: 3-20%, and H2O: 3-70%.

5. The preparation method according to claim 1, characterized in that: In step ⑥, the mass ratio of the components of the lubricant is engine oil: flake graphite: molybdenum disulfide = 5:4:1.

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