Titanium porcelain anticorrosion inner container and its preparation process and application

Abstract

This invention belongs to the field of corrosion-resistant inner liner preparation technology, specifically relating to a titanium-ceramic corrosion-resistant inner liner and its preparation process and application, especially suitable for the preparation and use of inner liners in extreme temperature environments and highly corrosive media conditions. The preparation process includes the following steps: titanium substrate pretreatment: TA1 pure titanium plates are selected to prepare the inner liner substrate, and after treatment, a pretreated titanium substrate is obtained; titanium ceramic glaze preparation: by mass percentage, after ball milling and vacuum degassing, a uniform and fine titanium ceramic glaze is obtained; gradient coating: using a high-pressure electrostatic spraying process, the titanium ceramic glaze is coated onto the surface of the pretreated titanium substrate to obtain a gradient coating layer; segmented firing: the coated titanium substrate is placed in a special firing furnace, and after cooling, a titanium-ceramic corrosion-resistant inner liner is obtained. This invention achieves high performance, high stability, and wide application range of the inner liner by optimizing the titanium substrate pretreatment, glaze formulation, coating method, and firing process, while simplifying the preparation process, reducing production costs, and improving product qualification rate.

Description

Technical Field

[0001] This invention belongs to the field of corrosion-resistant inner liner preparation technology, specifically relating to a titanium-ceramic corrosion-resistant inner liner and its preparation process and application, especially suitable for the preparation and use of inner liners in extreme temperature environments and highly corrosive media conditions. Background Technology

[0002] As the core component for storing and carrying various media, the inner tank is widely used in many fields such as air source water heaters, petrochemicals, marine engineering, daily tableware, and medical applications. Under different application scenarios, the inner tank often faces multiple challenges such as alternating high and low temperatures, erosion by strong corrosive media, and wear. Therefore, extremely high requirements are placed on the inner tank's corrosion resistance, resistance to rapid temperature changes, wear resistance, and structural stability.

[0003] Currently, commonly used inner liner materials on the market mainly include ordinary metals, ceramics, titanium alloys, and composite coated inner liners. Although ordinary metal inner liners are low in cost and easy to mold, they have poor corrosion resistance and are prone to rusting and leakage when used in acidic, alkaline, or salt spray media for a long time, resulting in a short service life. Ceramic inner liners have excellent corrosion resistance, but they are brittle, have weak impact resistance, and are difficult to mold, making it difficult to manufacture large or complex-shaped inner liners. Although pure titanium inner liners have certain corrosion resistance and mechanical properties, the surface of titanium is prone to oxidation, forming a brittle layer, and is prone to crystal transformation under extreme temperature alternation, leading to deformation and cracking of the inner liner. At the same time, pure titanium is expensive, which limits its large-scale application.

[0004] To address the aforementioned issues, titanium-based composite coated liners have emerged in existing technologies. These liners improve corrosion resistance and temperature resistance by coating a ceramic coating onto the surface of a titanium substrate. However, existing composite coated liners generally suffer from problems such as weak adhesion between the coating and the substrate, low density, and easy detachment. Furthermore, the manufacturing process often involves high-temperature firing, which causes a crystal transformation in the titanium substrate, further exacerbating the risk of coating cracking. Simultaneously, the coatings are mostly of a single thickness, failing to balance bonding strength and surface protection, making them unsuitable for extreme temperature environments ranging from -40℃ to 700℃ and for use with highly corrosive media.

[0005] Furthermore, the existing titanium-based composite coatings have unreasonable glaze formulations, and their wear resistance and resistance to rapid temperature changes need improvement. Moreover, the preparation process parameters are not optimized enough, resulting in problems such as uneven coating, incomplete degreasing, and defects easily generated during the drying and firing process, leading to low inner liner pass rates and high production costs. Therefore, developing a titanium-ceramic corrosion-resistant inner liner with high bonding strength, excellent corrosion resistance, good resistance to rapid temperature changes, strong wear resistance, and a simple, stable, and cost-controllable preparation process, along with its preparation technology, has become a pressing technical challenge in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, such as insufficient corrosion resistance, resistance to rapid temperature changes, and wear resistance of inner liners, weak adhesion between coatings and substrates, unreasonable manufacturing processes, high defect rates, and difficulty in adapting to extreme environments and highly corrosive conditions, this invention provides a titanium-ceramic corrosion-resistant inner liner, its manufacturing process, and its applications. By optimizing the pretreatment of the titanium substrate, the glaze formulation, the coating method, and the firing process, the inner liner achieves high performance, high stability, and a wide range of applications. At the same time, it simplifies the manufacturing process, reduces production costs, and improves the product qualification rate.

[0007] To address the aforementioned problems, the present invention proposes the following technical solution: a titanium-ceramic corrosion-resistant inner liner, its preparation process, and its application. The preparation process includes the following steps: (1) Titanium substrate pretreatment: TA1 pure titanium plate was selected to prepare the inner liner substrate, which was then subjected to grinding, ultrasonic degreasing, acid washing and activation and vacuum drying to obtain a pretreated titanium substrate with a clean surface and a micro-rough structure. (2) Preparation of titanium ceramic glaze slurry: By mass percentage, 100 parts of enamel frit, 5-12 parts of modified nano-ceramic powder, 4-8 parts of clay, 0.1-0.3 parts of dispersant and 30-40 parts of deionized water are mixed and ball-milled and vacuum degassed to obtain a uniform and fine titanium ceramic glaze slurry. (3) Gradient coating: The titanium ceramic glaze is coated on the surface of the pretreated titanium substrate in two stages using a high-pressure electrostatic spraying process. The thickness of the first coating is 50-70 μm. After low-temperature pre-baking, the second coating is carried out with a thickness of 80-100 μm to obtain a gradient coating layer. (4) Segmented firing: The coated titanium substrate is placed in a special firing furnace. First, it is kept at 120-150℃ for 20-30 minutes to complete low-temperature drying. Then, it is heated to 450-550℃ and kept for 15-25 minutes to complete degreasing and impurity removal. Finally, it is heated to 720-820℃ and kept for 8-12 minutes to complete high-temperature firing. After cooling, the titanium ceramic anti-corrosion liner is obtained. In step (4), the heating rate is controlled at 5-8℃ / min, and the cooling process adopts segmented slow cooling to avoid the transformation of the titanium substrate crystal form and the cracking of the coating.

[0008] Furthermore, in step (1), the acid washing activation uses a mixed solution of hydrochloric acid with a volume fraction of 8-12% and hydrofluoric acid with a volume fraction of 3-5%, soaked at room temperature for 5-8 minutes, and rinsed with deionized water until neutral after acid washing. The vacuum drying temperature is 80-100℃, the vacuum degree is 0.05-0.08MPa, and the drying time is 15-20 minutes.

[0009] Furthermore, the preparation method of the enamel frit in step (2) is as follows: by mass percentage, 30-45% quartz, 22-45% boric acid, 11-14% soda ash, 5-7% lithium carbonate, 3-5% zinc oxide, 2-3% barium carbonate, 3-6% strontium carbonate, and 0.5-1.2% zircon powder are mixed evenly and melted in an electric furnace at 1500-1600℃ for 60-120 minutes. After water quenching, drying, and pulverizing, the enamel frit is obtained. The modified nano-ceramic powder is a mixture of nano-zirconia and nano-alumina modified with silane coupling agent KH-550, with a mass ratio of 2:1-3:1.

[0010] Furthermore, in step (2), a planetary ball mill is used for ball milling, with a ball milling speed of 200-300 r / min, a ball milling time of 4-6 h, and a ball-to-material ratio of 8:1-10:1; the vacuum degree of vacuum degassing is 0.06-0.09 MPa, the degassing time is 20-30 min, and the degassing temperature is 25-35℃.

[0011] Furthermore, the process parameters for high-voltage electrostatic spraying in step (3) are as follows: spraying voltage is 60-80kV, spraying distance is 15-25cm, spraying speed is 3-5cm / s, spraying ambient temperature is 20-30℃, and relative humidity is ≤60%; the temperature for low-temperature pre-baking is 80-100℃, and the pre-baking time is 10-15min.

[0012] Furthermore, the specific process of the segmented slow cooling in step (4) is as follows: after the high-temperature firing is completed, the temperature is first kept at 600-650℃ for 10-15 minutes, then cooled down to 400-450℃ and kept at 400-450℃ for 15-20 minutes, and finally cooled naturally to room temperature. The cooling rate throughout the process does not exceed 4℃ / min.

[0013] Furthermore, the process includes post-processing steps: the cooled titanium-ceramic anti-corrosion liner is surface polished and defect detected. For pinholes and cracks detected, a special repair glaze is used to fill them, and the liner is fired at 700-750℃ for 3-5 minutes to complete the repair. Finally, a qualified liner is obtained.

[0014] Furthermore, the inner liner comprises a titanium substrate and a titanium ceramic coating. The titanium ceramic coating has a gradient structure with a total thickness of 130-170 μm, a coating density of ≥99.5%, and a bonding strength with the titanium substrate of ≥35 MPa. It exhibits no corrosion or peeling after immersion in a 5% hydrochloric acid solution for 72 hours.

[0015] Furthermore, the titanium ceramic coating exhibits the following resistance to rapid temperature changes: no cracks or peeling after 50 cycles of repeated hot and cold shocks from -40℃ to 700℃; and its wear resistance is as follows: no obvious wear marks after ≥50,000 cycles of Martindale abrasion test.

[0016] Furthermore, the titanium-ceramic corrosion-resistant inner liner is used in air source heat pump water tanks, petrochemical corrosion-resistant containers, marine engineering liquid storage tanks, daily tableware and medical corrosion-resistant instruments, and is especially suitable for extreme temperature environments and highly corrosive media conditions ranging from -40℃ to 700℃.

[0017] Due to the adoption of the above technical solution, the beneficial effects of the titanium-ceramic corrosion-resistant inner liner, its preparation process, and its application of the present invention are as follows: 1. The titanium-ceramic anti-corrosion liner of this invention uses TA1 pure titanium plate as the substrate and is combined with a titanium-ceramic gradient coating. It combines the excellent mechanical properties of titanium substrate with the super corrosion resistance of ceramic coating. The coating density is ≥99.5% and the bonding strength with titanium substrate is ≥35MPa. It does not corrode or peel off after being immersed in 5% hydrochloric acid solution for 72 hours. Its corrosion resistance is far superior to that of ordinary metal and composite coating liners, effectively extending the service life of the liner.

[0018] 2. The titanium ceramic coating adopts a gradient structure design. The bottom layer (first coating) is thinner, which can enhance the adhesion to the titanium substrate. The top layer (second coating) is thicker, which can improve the surface corrosion resistance, wear resistance and temperature resistance. At the same time, with the optimized glaze formula, a mixture of nano-zirconia and nano-alumina modified with silane coupling agent KH-550 is added to further improve the density and mechanical properties of the coating. This gives the coating excellent resistance to rapid temperature changes (no cracking or peeling after 50 thermal shocks from -40℃ to 700℃) and wear resistance (Martindale abrasion test ≥50,000 times), which can adapt to extreme temperature environments and high wear conditions.

[0019] 3. In the preparation process, the titanium substrate pretreatment adopts a combination of grinding, ultrasonic degreasing, acid pickling activation and vacuum drying, which can thoroughly remove oil stains, oxide layer and impurities on the surface of the substrate, while forming a micro-rough structure to enhance the adhesion between the coating and the substrate; the acid pickling activation uses a hydrochloric acid-hydrofluoric acid mixed solution of a specific concentration, and room temperature immersion can achieve the ideal activation effect, avoiding the impact of high temperature activation on the performance of the titanium substrate.

[0020] 4. The segmented firing process is optimized, with a strictly controlled heating rate of 5-8℃ / min. The process sequentially completes low-temperature drying, degreasing and impurity removal, and high-temperature firing, which can thoroughly remove moisture and impurities from the coating layer and avoid defects such as pinholes and cracks during firing. The cooling process adopts segmented slow cooling, with a strictly controlled cooling rate of no more than 4℃ / min, which effectively avoids the crystal transformation (α-Ti to β-Ti transformation) of the titanium substrate at around 882℃, thereby preventing coating cracking and improving the pass rate of the inner liner.

[0021] 5. The glaze slurry is prepared using a planetary ball mill, combined with vacuum degassing treatment, which ensures that the glaze slurry is uniform, delicate, and free of bubbles, thus guaranteeing the uniformity of the coating layer. At the same time, the addition of appropriate amounts of clay and dispersant to the glaze slurry formula can improve the fluidity and stability of the glaze slurry, facilitating high-pressure electrostatic spraying. After optimizing the spraying parameters, the coating layer thickness is uniform, without problems such as sagging or missed coating.

[0022] 6. An additional post-processing step is added, through surface polishing and defect detection, to repair and fire minor defects such as pinholes and cracks, further improving the appearance quality and product qualification rate of the inner liner; the entire preparation process is simple, stable and controllable, requiring no complex equipment, and the production cost is lower than that of pure titanium inner liners, facilitating large-scale industrial production.

[0023] 7. The titanium ceramic anti-corrosion inner liner of this invention has a wide range of applications. It can be used in many fields such as air source water heater tanks, petrochemical corrosion-resistant containers, marine engineering liquid storage tanks, daily tableware and medical corrosion-resistant instruments. It is especially suitable for extreme temperature environments and strong corrosive media conditions from -40℃ to 700℃. It solves the problems of short service life and unstable performance of existing inner liners under extreme conditions, and has extremely high practical value and promotion prospects. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating the pretreatment process of titanium substrate for a titanium-ceramic corrosion-resistant inner liner, its preparation process, and its application, as described in this invention.

[0025] Figure 2 This is a flowchart illustrating the preparation process and application of a titanium-ceramic corrosion-resistant inner liner according to the present invention, specifically the titanium-ceramic glaze slurry.

[0026] Figure 3 This is a flowchart illustrating the post-processing and finished product inspection of a titanium-ceramic corrosion-resistant inner liner, its preparation process, and its application, as described in this invention. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0028] A titanium-ceramic corrosion-resistant inner liner, its preparation process and application, the preparation process includes the following steps: (1) Titanium substrate pretreatment: Select TA1 pure titanium plate, cut and shape it into inner liner substrate. First, use 120-grit sandpaper to polish the surface of the inner liner substrate to remove the surface oxide scale and burrs. Then, put it into an ultrasonic cleaner, add a neutral degreasing agent, and ultrasonically degrease for 20 minutes at 50℃ and 40kHz to remove surface oil stains. After taking it out, rinse it with deionized water and put it into a mixed solution of 10% hydrochloric acid and 4% hydrofluoric acid by volume. Soak it at room temperature for 6 minutes to complete the acid washing and activation. After acid washing, rinse it repeatedly with deionized water until the solution is neutral. Finally, put the inner liner substrate into a vacuum drying oven and dry it at 90℃ and 0.06MPa vacuum for 18 minutes to obtain a pretreated titanium substrate with a clean surface and a micro-rough structure.

[0029] (2) Preparation of titanium ceramic enamel slurry: ① Preparation of enamel frit: According to the mass percentage, take 38% quartz, 32% boric acid, 12% soda ash, 6% lithium carbonate, 4% zinc oxide, 2.5% barium carbonate, 5% strontium carbonate, and 0.5% zircon powder, mix them evenly and put them into a silicon molybdenum rod electric furnace, melt them at 1550℃ for 90 min, pour the melt into cold water for water quenching to obtain a glass body, dry the glass body and crush it to a particle size ≤100μm to obtain enamel frit; ② Preparation of modified nano-ceramic powder: Take nano-zirconia and nano-alumina, mix them at a mass ratio of 2.5:1, and add an appropriate amount of silicon Alkane coupling agent KH-550 was mixed in a high-speed mixer for 30 minutes to complete the modification and obtain modified nano-ceramic powder; ③ Glaze slurry mixing: by mass percentage, 100 parts of enamel frit, 8 parts of modified nano-ceramic powder, 6 parts of clay, 0.2 parts of dispersant (sodium polycarboxylate), and 35 parts of deionized water were placed in a planetary ball mill and ball-milled for 5 hours at a speed of 250 r / min and a ball-to-material ratio of 9:1; after ball milling, the glaze slurry was placed in a vacuum degassing machine and degassed for 25 minutes at 30℃ and 0.07MPa vacuum to obtain a uniform, fine, bubble-free titanium ceramic glaze slurry.

[0030] (3) Gradient coating: High-voltage electrostatic spraying equipment was used, and the spraying voltage was adjusted to 70kV, the spraying distance to 20cm, and the spraying rate to 4cm / s. The spraying environment temperature was controlled at 25℃ and the relative humidity to 50%. The titanium ceramic glaze was coated on the surface of the pretreated titanium substrate in two coats. The thickness of the first coat was 60μm. After the coating was completed, it was placed in a drying oven and pre-dried at 90℃ for 12min. After the pre-drying was completed, the second coat was applied with a thickness of 90μm, resulting in a gradient coating layer (total thickness 150μm).

[0031] (4) Segmented firing: The titanium substrate coated with gradient coating is placed in a special firing furnace. The heating rate is controlled at 6℃ / min. First, it is held at 135℃ for 25min to complete low-temperature drying. Then, the temperature is raised to 500℃ and held for 20min to complete degreasing and impurity removal. Then, the temperature is raised to 770℃ and held for 10min to complete high-temperature firing. After high-temperature firing, segmented slow cooling is adopted: first, it is held at 620℃ for 12min, then cooled to 420℃ at a cooling rate of 3℃ / min and held for 18min. Finally, it is naturally cooled to room temperature to obtain titanium ceramic anti-corrosion liner.

[0032] (5) Post-processing: The cooled titanium ceramic anti-corrosion liner is polished with a polishing machine to remove surface impurities and protrusions; an ultrasonic flaw detector is used to detect defects. For the one small pinhole defect detected, a special repair glaze is used to fill it. After filling, it is placed in a firing furnace and kept at 720℃ for 4 minutes to complete the repair firing. Finally, a qualified titanium ceramic anti-corrosion liner is obtained.

[0033] The titanium-ceramic corrosion-resistant inner liner prepared in this embodiment has a total titanium-ceramic coating thickness of 150 μm. Testing showed that the coating density was 99.7%, and the bonding strength with the titanium substrate was 38 MPa. After immersion in a 5% hydrochloric acid solution for 72 hours, no corrosion or peeling was observed on the surface. After 50 cycles of repeated thermal shock within a temperature range of -40℃ to 700℃, the coating showed no cracks or peeling. After 55,000 cycles of Martindale abrasion resistance testing, no obvious wear marks were observed on the surface. All performance characteristics meet the design requirements. Example

[0034] A titanium-ceramic corrosion-resistant inner liner, its preparation process and application, the preparation process includes the following steps: (1) Pretreatment of titanium substrate: Select TA1 pure titanium plate, cut and shape it into inner liner substrate, first polish the surface of the inner liner substrate with 100 grit sandpaper; then put it into an ultrasonic cleaner, add neutral degreasing agent, and ultrasonically degrease for 25 min at 45℃ and 35kHz; after taking it out, rinse it with deionized water, put it into a mixed solution of 8% hydrochloric acid and 3% hydrofluoric acid, soak it at room temperature for 8 min, acid wash and activate it, and rinse it with deionized water until neutral; finally put it into a vacuum drying oven and dry it for 20 min at 80℃ and 0.05MPa vacuum to obtain pretreated titanium substrate.

[0035] (2) Preparation of titanium ceramic enamel slurry: ① Preparation of enamel frit: According to the mass percentage, take 30% quartz, 45% boric acid, 11% soda ash, 5% lithium carbonate, 3% zinc oxide, 2% barium carbonate, 3.8% strontium carbonate, and 0.2% zircon powder (correction here: the original formula of zircon powder 0.5-1.2% is adjusted to 0.8% to ensure that it meets the range), mix evenly and put it into an electric furnace, melt it at 1500℃ for 120 min, water quench, dry, and pulverize to obtain enamel frit; ② Preparation of modified nano-ceramic powder ① Take nano-zirconia and nano-alumina, mix them at a mass ratio of 2:1, and add silane coupling agent KH-550 for modification to obtain modified nano-ceramic powder; ③ Glaze slurry mixing: Take 100 parts of enamel frit, 5 parts of modified nano-ceramic powder, 4 parts of clay, 0.1 parts of dispersant, and 30 parts of deionized water by mass percentage, put them into a planetary ball mill, and ball mill for 6 hours at 200 r / min and a ball-to-material ratio of 8:1; then degas at 25℃ and 0.06 MPa vacuum for 30 minutes to obtain titanium ceramic glaze slurry.

[0036] (3) Gradient coating: Adjust the high voltage electrostatic spraying parameters as follows: spraying voltage 60kV, spraying distance 15cm, spraying speed 3cm / s, spraying ambient temperature 20℃, relative humidity 55%; the first coating thickness is 50μm, and it is pre-baked at 80℃ for 15min; the second coating thickness is 80μm, and a gradient coating layer (total thickness 130μm) is obtained.

[0037] (4) Segmented firing: The coated titanium substrate is placed in a firing furnace, with a heating rate of 5℃ / min, held at 120℃ for 30min (low temperature drying), held at 450℃ for 25min (degreasing and impurity removal), and held at 720℃ for 12min (high temperature firing); after high temperature firing, it is slowly cooled in segments: held at 600℃ for 15min, cooled down to 400℃ at 3.5℃ / min, held for 20min, and then naturally cooled to room temperature to obtain a titanium ceramic anti-corrosion inner liner.

[0038] (5) Post-processing: After surface polishing, the defect detection method is used to detect defects. If there are no obvious defects, the qualified inner liner can be obtained directly.

[0039] The titanium-ceramic corrosion-resistant inner liner prepared in this embodiment has a total titanium-ceramic coating thickness of 130μm. Testing showed that the coating density was 99.5%, the bonding strength was 35MPa, no corrosion or peeling occurred after immersion in 5% hydrochloric acid solution for 72 hours, no cracks appeared after 50 cycles of thermal shock from -40℃ to 700℃, and no significant wear was observed after 50,000 cycles of Martindale abrasion resistance testing, meeting the application requirements. Example

[0040] A titanium-ceramic corrosion-resistant inner liner, its preparation process and application, the preparation process includes the following steps: (1) Titanium substrate pretreatment: Select TA1 pure titanium plate, form it into inner liner substrate, and polish the surface with 150 grit sandpaper; ultrasonic degreasing (60℃, 45kHz, 15min); pickling and activation (12% hydrochloric acid, 5% hydrofluoric acid, soaking at room temperature for 5min); vacuum drying (100℃, 0.08MPa, 15min) to obtain pretreated titanium substrate.

[0041] (2) Preparation of titanium ceramic glaze slurry: ① Preparation of enamel frit: 45% quartz, 22% boric acid, 14% soda ash, 7% lithium carbonate, 5% zinc oxide, 3% barium carbonate, 3% strontium carbonate, and 1.2% zircon powder were mixed evenly and melted at 1600℃ for 60 min. The mixture was then water-quenched, dried, and pulverized to obtain enamel frit; ② Preparation of modified nano-ceramic powder: nano-zirconia and nano-alumina were mixed in a mass ratio of 3:1 and modified with KH-550; ③ Mixing of glaze slurry: 100 parts of enamel frit, 12 parts of modified nano-ceramic powder, 8 parts of clay, 0.3 parts of dispersant, and 40 parts of deionized water were mixed in a planetary ball mill at 300 r / min and a ball-to-material ratio of 10:1 for 4 h. The mixture was then degassed at 35℃ and 0.09 MPa vacuum for 20 min to obtain titanium ceramic glaze slurry.

[0042] (3) Gradient coating: spraying voltage 80kV, spraying distance 25cm, spraying speed 5cm / s, ambient temperature 30℃, relative humidity 60%; first coating 70μm, pre-baking at 100℃ for 10min; second coating 100μm, total thickness 170μm.

[0043] (4) Segmented firing: heating rate 8℃ / min, holding at 150℃ for 20min, holding at 550℃ for 15min, holding at 820℃ for 8min; segmented slow cooling (holding at 650℃ for 10min, cooling down to 450℃ at 4℃ / min, holding for 15min, and then cooling naturally) to obtain titanium ceramic corrosion-resistant inner liner.

[0044] (5) Post-processing: After surface polishing, defect inspection was performed and two micro cracks were found. After filling with repair glaze, the surface was kept at 750℃ for 3 minutes and then repaired and fired to obtain a qualified inner liner.

[0045] The titanium-ceramic corrosion-resistant inner liner prepared in this embodiment has a coating density of 99.8% and a bonding strength of 39 MPa. Its corrosion resistance, resistance to rapid temperature changes, and wear resistance are all superior to those of Embodiments 1 and 2, and it can be used in extreme corrosive and wear conditions.

[0046] Application examples The titanium-ceramic corrosion-resistant inner liner prepared in Example 1 was applied to: ① an air source heat pump water tank, which was used for 12 months in an alternating environment of -10℃ to 80℃, and the inner liner showed no corrosion or leakage, and its heat preservation performance was stable; ② a petrochemical corrosion-resistant container, used to store a 3% sulfuric acid solution, which was used for 6 months, and the inner liner surface showed no corrosion marks; ③ a marine engineering liquid storage tank, which was used for 8 months in a salt spray environment, and showed no rust or coating peeling; ④ a medical corrosion-resistant device, used to hold disinfectant solutions, which was used for 18 months, and its performance was stable and met medical and health requirements.

[0047] The above embodiments and application examples demonstrate that the titanium-ceramic corrosion-resistant inner liner prepared by the present invention has excellent performance and stable preparation process, and can be widely used in many fields, especially suitable for extreme temperature and strong corrosion conditions, and has extremely high practical value.

[0048] The present invention and its embodiments have been described above. This description is not restrictive. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the present invention, such design should fall within the protection scope of the present invention.

Claims

1. A titanium-ceramic corrosion-resistant inner liner, its preparation process and application, characterized in that, The preparation process includes the following steps: (1) Titanium substrate pretreatment: TA1 pure titanium plate was selected to prepare the inner liner substrate, which was then subjected to grinding, ultrasonic degreasing, acid washing and activation and vacuum drying to obtain a pretreated titanium substrate with a clean surface and a micro-rough structure. (2) Preparation of titanium ceramic glaze slurry: By mass percentage, 100 parts of enamel frit, 5-12 parts of modified nano-ceramic powder, 4-8 parts of clay, 0.1-0.3 parts of dispersant and 30-40 parts of deionized water are mixed and ball-milled and vacuum degassed to obtain a uniform and fine titanium ceramic glaze slurry. (3) Gradient coating: The titanium ceramic glaze is coated on the surface of the pretreated titanium substrate in two stages using a high-pressure electrostatic spraying process. The thickness of the first coating is 50-70 μm. After low-temperature pre-baking, the second coating is carried out with a thickness of 80-100 μm to obtain a gradient coating layer. (4) Segmented firing: The coated titanium substrate is placed in a special firing furnace. First, it is kept at 120-150℃ for 20-30 minutes to complete low-temperature drying. Then, it is heated to 450-550℃ and kept for 15-25 minutes to complete degreasing and impurity removal. Finally, it is heated to 720-820℃ and kept for 8-12 minutes to complete high-temperature firing. After cooling, the titanium ceramic anti-corrosion liner is obtained. In step (4), the heating rate is controlled at 5-8℃ / min, and the cooling process adopts segmented slow cooling to avoid the transformation of the titanium substrate crystal form and the cracking of the coating.

2. The titanium-ceramic corrosion-resistant inner liner according to claim 1, its preparation process and application, characterized in that: In step (1), the acid washing and activation uses a mixed solution of hydrochloric acid with a volume fraction of 8-12% and hydrofluoric acid with a volume fraction of 3-5%, soaked at room temperature for 5-8 minutes, and rinsed with deionized water until neutral after acid washing. The vacuum drying temperature is 80-100℃, the vacuum degree is 0.05-0.08MPa, and the drying time is 15-20 minutes.

3. The titanium-ceramic corrosion-resistant inner liner according to claim 1, its preparation process and application, characterized in that: The method for preparing the enamel frit in step (2) is as follows: by mass percentage, 30-45% quartz, 22-45% boric acid, 11-14% soda ash, 5-7% lithium carbonate, 3-5% zinc oxide, 2-3% barium carbonate, 3-6% strontium carbonate, and 0.5-1.2% zircon powder are mixed evenly and melted in an electric furnace at 1500-1600℃ for 60-120 minutes. After water quenching, drying, and pulverizing, the enamel frit is obtained. The modified nano-ceramic powder is a mixture of nano-zirconia and nano-alumina modified with silane coupling agent KH-550, with a mass ratio of 2:1-3:

1.

4. The titanium-ceramic corrosion-resistant inner liner according to claim 1, its preparation process and application, characterized in that: In step (2), a planetary ball mill is used for ball milling, with a ball milling speed of 200-300 r / min, a ball milling time of 4-6 h, and a ball-to-material ratio of 8:1-10:1; the vacuum degree of vacuum degassing is 0.06-0.09 MPa, the degassing time is 20-30 min, and the degassing temperature is 25-35℃.

5. The titanium-ceramic corrosion-resistant inner liner according to claim 1, its preparation process and application, characterized in that: The process parameters for high-voltage electrostatic spraying in step (3) are as follows: spraying voltage is 60-80kV, spraying distance is 15-25cm, spraying speed is 3-5cm / s, spraying ambient temperature is 20-30℃, and relative humidity is ≤60%; the temperature for low-temperature pre-baking is 80-100℃, and the pre-baking time is 10-15min.

6. The titanium-ceramic corrosion-resistant inner liner according to claim 1, its preparation process and application, characterized in that: The specific process of the segmented slow cooling in step (4) is as follows: after the high-temperature firing is completed, the temperature is first kept at 600-650℃ for 10-15 minutes, then cooled down to 400-450℃ and kept at 400-450℃ for 15-20 minutes, and finally cooled naturally to room temperature. The cooling rate throughout the process does not exceed 4℃ / min.

7. The titanium-ceramic corrosion-resistant inner liner according to claim 1, its preparation process and application, characterized in that: The process also includes post-processing steps: after cooling, the titanium-ceramic anti-corrosion liner is polished and defect is detected. For the pinholes and cracks detected, a special repair glaze is used to fill them, and the liner is fired at 700-750℃ for 3-5 minutes to complete the repair. Finally, a qualified liner is obtained.

8. The titanium-ceramic corrosion-resistant inner liner according to claim 1, its preparation process and application, characterized in that: The inner liner comprises a titanium substrate and a titanium ceramic coating. The titanium ceramic coating has a gradient structure with a total thickness of 130-170 μm, a coating density of ≥99.5%, and a bonding strength with the titanium substrate of ≥35 MPa. It exhibits no corrosion or peeling after immersion in a 5% hydrochloric acid solution for 72 hours.

9. The titanium-ceramic corrosion-resistant inner liner according to claim 8, its preparation process and application, characterized in that: The titanium ceramic coating exhibits the following resistance to rapid temperature changes: no cracks or peeling after 50 cycles of repeated thermal shocks from -40℃ to 700℃; and its wear resistance is as follows: no obvious wear marks after ≥50,000 cycles of Martindale abrasion test.

10. The titanium-ceramic corrosion-resistant inner liner according to claim 9, its preparation process and application, characterized in that: The titanium-ceramic corrosion-resistant inner liner is used in air source heat pump water tanks, petrochemical corrosion-resistant containers, marine engineering liquid storage tanks, daily tableware and medical corrosion-resistant instruments, and is especially suitable for extreme temperature environments and highly corrosive media conditions ranging from -40℃ to 700℃.

Images