Roller with nano ceramic coating and manufacturing method thereof

Abstract

The invention discloses a roller with a nano ceramic coating and a manufacturing method of the roller, and belongs to the field of textile machinery parts, the roller comprises a cylinder, a base material of the cylinder is 42CrMo alloy steel with the hardness of HRC 28-32, a nitriding layer is arranged on the surface of the cylinder, the nano ceramic coating is arranged on the nitriding layer of the cylinder, the porosity of the nano ceramic coating is smaller than or equal to 1%, and the porosity of the nano ceramic coating is smaller than or equal to 1%. The surface components of the nano ceramic coating comprise 95 wt%-97 wt% of zirconium oxide and 3 wt%-5 wt% of yttrium oxide. The basic cylinder body has certain strength and toughness, and is matched with the nitriding layer and the compact nano ceramic coating, so that the roller has high hardness, high wear resistance and good chemical stability, the service life of the roller is greatly prolonged, the surface roughness increase caused by wear is reduced, the damage to fibers is reduced, and the service life of the roller is prolonged. Meanwhile, the nano ceramic coating optimizes the surface performance of the barrel body, the yarn end breakage rate can be reduced, and the yarn quality uniformity is improved.

Description

Technical Field

[0001] The invention relates to a roller with a nano-ceramic coating and a manufacturing method thereof, and belongs to the field of textile machinery parts. Background Art

[0002] In the field of textile machinery, rollers are a crucial component, combining the functions of rollers and shafts, primarily used for drafting, feeding, and transporting fibers. Limited by the inherent properties of steel, traditional steel rollers still lack sufficient surface hardness and wear resistance, which makes them prone to wear and tear, increasing surface roughness and shortening the roller's service life. During the process of gripping and transporting fibers, they can easily damage or snag the fibers, affecting their normal drafting and output, ultimately leading to an increase in yarn breakage rates and a decrease in the CV value of the output yarn, seriously affecting the quality and uniformity of the yarn. Consequently, traditional steel rollers require frequent replacement, resulting in high production costs in the textile industry.

[0003] High yarn breakage rates have long plagued textile production. Frequent yarn breakage not only reduces production efficiency and increases labor costs, but also results in raw material waste. Traditional steel rollers struggle to maintain high and stable precision over time, resulting in large fluctuations in yarn evenness (CV) values, making it difficult to produce high-quality, uniform yarn products. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the present invention provides a roller with a nano-ceramic coating and a manufacturing method thereof. The use of the roller can reduce the yarn breakage rate and lower the yarn evenness CV value.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] In a first aspect, the present application provides a roller with a nano-ceramic coating, comprising a cylindrical body, the cylindrical body base being made of 42CrMo alloy steel with a hardness of HRC 28-32, the cylindrical body surface having a nitrided layer, and the cylindrical body being provided with a nano-ceramic coating on the nitrided layer. The nano-ceramic coating has a porosity of ≤1%, and the surface composition of the nano-ceramic coating includes 95wt%-97wt% zirconium oxide and 3wt%-5wt% yttrium oxide. The surface of the nano-ceramic coating specifically refers to the shallowest 10μm range of the coating.

[0007] The nano-ceramic coating rollers provided in this application have a certain strength and toughness. The nitrided layer on the surface of the rollers significantly improves the surface hardness and wear resistance, and to a certain extent, strengthens the bonding between the substrate and the nano-ceramic coating. The coating surface components include zirconium oxide, which has high hardness, high wear resistance, and good chemical stability, while yttrium oxide stabilizes the zirconia's crystal structure. The combination of the two significantly extends the roller's service life, effectively reduces yarn breakage rates, and improves yarn quality uniformity.

[0008] Furthermore, the roller with the nano-ceramic coating has a surface hardness of ≥1300 HV and a surface friction coefficient of 0.05 to 0.07.

[0009] The roller of the present application is not easily worn on its own surface during the process of contacting with the fiber and stretching, feeding and conveying it; it has appropriate roughness, and is not easy to slip relative to the fiber, nor is it easy to wear the fiber. Even after long-term use, the increase in surface roughness is extremely slow, and it can always maintain a good surface state, stably convey the fiber, and make the fiber drafting process more uniform and stable, which is beneficial to improving the uniformity of the output yarn, reducing the CV value of the yarn, and improving the yarn quality.

[0010] Furthermore, the nano ceramic coating includes four stacked layers, which are in the following order from closest to the nitriding layer to farthest from the nitriding layer:

[0011] The first layer contains 80 wt% zirconium oxide and 20 wt% yttrium oxide;

[0012] The second layer contains 90 wt% zirconium oxide and 10 wt% yttrium oxide;

[0013] The third layer contains 95 wt% zirconium oxide and 5 wt% yttrium oxide;

[0014] The fourth layer contains 97 wt% zirconium oxide and 3 wt% yttrium oxide.

[0015] The zirconium oxide content gradually increases, while the yttrium oxide content gradually decreases. The higher yttrium oxide content helps to better bond with the nitriding layer and provides a good foundation for the deposition of subsequent coatings. As the layer moves away from the nitriding layer, the zirconium oxide content gradually increases, giving full play to the high hardness, high strength and high wear resistance of zirconium oxide.

[0016] This gradient composition design allows the coating's performance to be gradually optimized from the inside out. While ensuring good bonding with the nitriding layer, the outer layer has higher hardness and wear resistance to better cope with the friction and wear caused by direct contact with the fibers. At the same time, the entire coating structure is more stable and works together on the rollers, effectively improving the roller's performance in the textile process, reducing damage to the fibers, and helping to improve yarn quality.

[0017] Furthermore, the thickness of the nano-ceramic coating is 50±5 μm.

[0018] This thickness is sufficient to construct four layers of coating with varying compositions (the first to fourth layers), and has a certain thickness to optimize the surface properties of the 42CrMo alloy steel; at the same time, the coating thickness will not be too thick to avoid reducing the bonding strength with the cylinder.

[0019] In a second aspect, the present application provides a method for manufacturing a roller having a nano-ceramic coating, comprising the following steps:

[0020] The 42CrMo alloy steel with a hardness of HRC28 to 32 is machined into a cylinder;

[0021] Performing ion nitriding treatment on the cylinder to form a nitrided layer on the surface of the cylinder;

[0022] Depositing a nano-ceramic coating on the surface of the cylinder so that the surface composition of the nano-ceramic coating includes 95wt% to 97wt% of zirconium oxide and 3wt% to 5wt% of yttrium oxide;

[0023] Laser remelting the nano-ceramic coating to make the porosity of the nano-ceramic coating ≤1%;

[0024] The surface is polished to obtain the roller with the nano-ceramic coating.

[0025] The cylinder is machined from 42CrMo alloy steel with a hardness of HRC28-32, providing a matrix with suitable strength and toughness for the roller. Ion nitriding treatment forms a nitrided layer on the surface of the cylinder to improve the surface hardness and wear resistance. When depositing the nano-ceramic coating on the surface of the cylinder, its surface composition is controlled to ensure good bonding between the nano-ceramic coating and the cylinder. After laser remelting to reduce the porosity, the surface performance of the roller is optimized, which can reduce the yarn breakage rate and the CV value of the yarn evenness.

[0026] Furthermore, the ion nitriding treatment is performed at a temperature of 520° C. for 6 hours, forming a nitriding layer with a depth of 0.3 mm.

[0027] This nitriding process effectively improves the surface hardness and wear resistance of the cylinder. The appropriate nitriding temperature and time ensure that nitrogen atoms evenly penetrate the substrate surface, forming a dense and stable nitrided layer. The 0.3mm depth provides excellent support and bonding for the nano-ceramic coating, paving the way for subsequent nano-ceramic coating deposition and laser remelting.

[0028] Furthermore, in the step of depositing the nano-ceramic coating on the surface of the cylinder, plasma spraying is used, the particle size D50 of the raw material powder is 80nm, and the specific surface area is ≥45m 2 / g; the spraying power is 34kW~52kW, and the powder feeding rate is 25g / min; the cylinder is preheated to 250±10℃ before receiving plasma spraying.

[0029] Raw material powders of this particle size and specific surface area can be fully heated and melted during the plasma spraying process, evenly deposited on the cylinder surface, and form a high-quality nano-ceramic coating. Combined with appropriate spraying power and powder feed rate, the deposition efficiency and quality of the coating can be guaranteed. At the appropriate power, the raw material powder can be fully melted and deposited at an appropriate rate, forming a dense, uniform coating. Preheating the cylinder before plasma spraying can reduce the temperature difference between the coating and the cylinder, reduce coating defects caused by thermal stress, and improve the bonding strength between the coating and the cylinder. Subsequent steps such as laser remelting help ensure that the nano-ceramic coating has good performance and quality, thereby enabling the roller to improve yarn quality during the textile process.

[0030] Furthermore, in the step of depositing the nano-ceramic coating on the surface of the cylinder, the deposition is divided into four layers:

[0031] In the first layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 80:20;

[0032] In the second layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 90:10;

[0033] In the third layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 95:5;

[0034] In the fourth layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 97:3;

[0035] In the deposition order, the spray power of the next layer is reduced by 5% compared with the spray power of the previous layer.

[0036] The nano-ceramic coating is deposited in four layers, and the mass ratio of zirconium oxide to yttrium oxide in the raw materials of each layer is different. At the same time, according to the deposition order, the spray power of the next layer is reduced by 5% compared with the previous layer. This design realizes a gradient change in the composition and structure of the coating. Coatings with different composition ratios are deposited at different spray powers, allowing each layer to fully exert its specific function, such as high bonding strength in the first layer, transition buffering in the second layer, wear resistance enhancement in the third layer, and ultra-smooth surface in the fourth layer. The power reduction helps to achieve a gradient change in grain size, further optimize the performance of the coating, and the synergy between the layers improves the overall adhesion, wear resistance and surface quality of the coating, thereby improving the performance of the roller in the textile process, reducing damage to the fiber, and improving the quality of the yarn.

[0037] Furthermore, before the step of depositing the nano-ceramic coating on the surface of the cylinder, the cylinder is pretreated in the following order:

[0038] Sandblasting until the surface roughness Ra reaches 3μm~4μm;

[0039] Ultrasonic cleaning with organic solvents;

[0040] The surface was bombarded with argon plasma at a power of 300 W for 5 min.

[0041] Sandblasting the cylinder increases the roughness of the cylinder surface, increasing the contact area between the nano-ceramic coating and the cylinder, thereby improving the mechanical bond between the coating and the cylinder. Ultrasonic cleaning with organic solvents removes oil stains and impurities from the cylinder surface, ensuring a clean surface and facilitating the uniform deposition of subsequent coatings. Bombarding the surface with argon plasma further cleans the surface and activates surface atoms, increasing surface activity and strengthening the chemical bond between the coating and the cylinder. These pretreatment steps work closely with subsequent processes such as ion nitriding and nano-ceramic coating deposition to provide excellent surface conditions for the entire roller production process, ensuring the smooth progress of each process link, improving the overall quality and performance of the roller, and making the roller more stable and reliable during the textile process.

[0042] Furthermore, in the laser remelting step, the laser wavelength is 1064 nm, the power is 800 W, the scanning speed is 12 mm / s, and the overlap rate is 40%.

[0043] The process parameters can precisely control the laser remelting process, effectively reducing the porosity of the coating, which is beneficial to improving the overall quality and performance stability of the roller, enabling the roller to work stably for a long time during the textile process, reducing wear and improving yarn quality.

[0044] The beneficial effects of the present invention are as follows: in the present invention, the cylinder serving as the basis has certain strength and toughness, and combined with the nitriding layer and the dense nano-ceramic coating, the roller has high hardness, high wear resistance and good chemical stability, the service life of the roller is greatly extended, and the increase in surface roughness caused by wear is reduced, thereby reducing damage to the fiber. At the same time, the nano-ceramic coating optimizes the surface properties of the cylinder, which can reduce the yarn breakage rate and improve the uniformity of the yarn quality. DETAILED DESCRIPTION

[0045] To make the purpose, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0046] It should be understood that, under the premise of no conflict, any and all embodiments of the present invention can be combined with the technical features in any other embodiment or multiple other embodiments to obtain additional embodiments. The present invention includes such combinations to obtain additional embodiments.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the claimed subject matter belongs. If there is an inconsistency between the definitions of terms in different sections of the specification, the definitions provided in this section shall control.

[0048] The embodiment of the present application provides a roller with a nano ceramic coating, and a brief manufacturing process is as follows:

[0049] S1: preparing a base material (a cylinder).

[0050] S2: preparing a nano ceramic coating on the base material.

[0051] S3: laser remelting.

[0052] S4: surface lapping.

[0053] In step S1, the raw material of the base material can be 42CrMo alloy steel (for example, hardness HRC 28-32, tensile strength ≥1080MPa).

[0054] The raw material of the base material is processed as follows:

[0055] S11: precision turning (for example, diameter φ27±0.01mm, surface roughness Ra0.8μm).

[0056] S12: ion nitriding treatment (for example, temperature 520℃, time 6h, penetration depth 0.3mm).

[0057] S13: superfinishing (for example, roundness ≤0.003mm, straightness ≤0.005mm / 300mm).

[0058] Step S2 preferably uses plasma spraying.

[0059] The spraying material is selected from ZrO2 (zirconia) + Y2O3 (yttria), and the particle size requirement is: nano-level powder (for example, D50=80nm, specific surface area ≥45m 2 / g).

[0060] The plasma spraying process parameters are as follows: spraying power is 42kW (current 550A, voltage 75V); powder feeding rate is 25g / min (argon carrier gas flow is 3L / min); spraying distance is 120mm; cylinder preheating temperature is 250±10℃, to prevent cracking.

[0061] Step S3 can use a fiber laser (wavelength 1064nm, power 800W), scanning speed is 12mm / s, and the overlap rate is 40%, which can reduce the porosity of the coating (from 8% to ≤1%).

[0062] In step S4, diamond grinding wheel polishing (grain size W5, rotation speed 3000 rpm) can be used to make the roller surface roughness reach Ra0.2 μm (mirror grade).

[0063] In a preferred embodiment, step S2 is prepared in four layers:

[0064] In the first layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 80:20;

[0065] In the second layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 90:10;

[0066] In the third layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 95:5;

[0067] In the fourth layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 97:3.

[0068] And according to the deposition sequence, the spraying power of the next layer is reduced by 5% compared with the spraying power of the previous layer, so as to realize the gradient change of the grain size (gradient change from 200nm to 50nm).

[0069] The proportions of zirconium oxide and yttrium oxide in each layer are different. The first layer close to the nitriding layer contains 80wt% zirconium oxide and 20wt% yttrium oxide. The higher proportion of yttrium oxide gives it a high bonding strength with the nitriding layer, ensuring that the coating is not easy to fall off. The second layer contains 90wt% zirconium oxide and 10wt% yttrium oxide, which acts as a transition buffer to alleviate the thermal stress problem caused by composition differences between different layers. The third layer contains 95wt% zirconium oxide and 5wt% yttrium oxide, focusing on enhancing wear resistance. The outermost layer contains 97wt% zirconium oxide and 3wt% yttrium oxide to achieve an ultra-smooth surface, reducing friction and damage to the fiber. The components and functions of each layer are interconnected to form a gradient change, which synergistically improves the overall comprehensive performance of the coating and enhances the roller's wear resistance, stability and fiber protection.

[0070] In a preferred embodiment, between step S1 and step S2, the barrel undergoes the following pretreatment sequence:

[0071] Sand blasting: For example, use white corundum sand with a particle size of 80 mesh to make the surface roughness of the cylinder reach Ra3.2μm.

[0072] Ultrasonic cleaning: The solvent is a mixture of acetone and ethanol, for example, a 1:1 volume mixture, an ultrasonic frequency of 40 kHz, and a time of 15 minutes.

[0073] Ion activation: For example, argon plasma bombardment with a power of 300W and a time of 5 minutes.

[0074] Combined with the above preferred embodiments, the thickness of the nano-ceramic coating on the roller is 50 μm, and the surface roughness Ra is 0.2 μm; the surface hardness reaches 1350 HV, which is 80% higher than the 750 HV of the traditional steel roller; the friction coefficient is 0.05, which is 58% lower than the 0.08 of the traditional steel roller; the wear resistance reaches 1.2 mg / km, which is 85% lower than the 8.5 mg / km of the traditional steel roller.

[0075] The wear resistance standard described above is based on the ring-block wear test specified in GB / T 12444-2006, Metallic Materials, Test Methods for Wear. The test equipment is an MRH-3 high-speed ring-block wear tester. The wear partner is a standard nitrile rubber block with a Shore A hardness of 80°. The test conditions are: a load of 50N and a linear speed of 1.5m / s. Wear resistance = (mass before test - mass after test) / wear mileage.

[0076] Example 1

[0077] The cylinder with a 0.3 mm nitrided layer is obtained by turning, ion nitriding and superfine grinding using 42CrMo alloy steel (hardness HRC30).

[0078] The nano ceramic coating is deposited on the pre-treated cylinder by plasma spraying. The spraying materials are zirconium oxide and yttrium oxide. The particle size requirements are: D50 = 80nm, and the specific surface area is ≥ 45m 2 / g. Spray one layer, the ratio of zirconium oxide to yttrium oxide is 97:3, and the coating thickness is 50±5μm.

[0079] Laser remelting: using fiber laser, wavelength 1064nm, power 800W, scanning speed 12mm / s, overlap rate 40%.

[0080] Finally, it was polished with a diamond grinding wheel with a grain size of W5 until the roughness reached Ra0.2μm.

[0081] Example 2

[0082] The cylinder with a 0.3 mm nitrided layer is obtained by turning, ion nitriding and superfine grinding using 42CrMo alloy steel (hardness HRC30).

[0083] The nano ceramic coating is deposited on the pre-treated cylinder by plasma spraying. The spraying materials are zirconium oxide and yttrium oxide. The particle size requirements are: D50 = 80nm, and the specific surface area is ≥ 45m 2 / g. A total of four layers were sprayed: the first layer contained 80wt% zirconium oxide and 20wt% yttrium oxide; the second layer contained 90wt% zirconium oxide and 10wt% yttrium oxide; the third layer contained 95wt% zirconium oxide and 5wt% yttrium oxide; and the fourth layer contained 97wt% zirconium oxide and 3wt% yttrium oxide. The total coating thickness was 50±5μm.

[0084] Laser remelting: using fiber laser, wavelength 1064nm, power 800W, scanning speed 12mm / s, overlap rate 40%.

[0085] Finally, it was polished with a diamond grinding wheel with a grain size of W5 until the roughness reached Ra0.2μm.

[0086] Comparative Example 1

[0087] The cylinder with a 0.3 mm nitrided layer is obtained by turning, ion nitriding and superfine grinding using 42CrMo alloy steel (hardness HRC30).

[0088] The nano ceramic coating is deposited on the pre-treated cylinder by plasma spraying. The spraying materials are zirconium oxide and yttrium oxide. The particle size requirements are: D50 = 80nm, and the specific surface area is ≥ 45m 2 / g. Spray one layer, the ratio of zirconium oxide to yttrium oxide is 97:3, and the coating thickness is 50±5μm.

[0089] Finally, it was polished with a diamond grinding wheel with a grain size of W5 until the roughness reached Ra0.2μm.

[0090] Comparative Example 2

[0091] The cylinder with a 0.3 mm nitrided layer is obtained by turning, ion nitriding and superfine grinding using 42CrMo alloy steel (hardness HRC30).

[0092] The nano ceramic coating is deposited on the pre-treated cylinder by plasma spraying. The spraying materials are zirconium oxide and yttrium oxide. The particle size requirements are: D50 = 80nm, and the specific surface area is ≥ 45m 2 / g. A total of four layers were sprayed: the first layer contained 80wt% zirconium oxide and 20wt% yttrium oxide; the second layer contained 90wt% zirconium oxide and 10wt% yttrium oxide; the third layer contained 95wt% zirconium oxide and 5wt% yttrium oxide; and the fourth layer contained 97wt% zirconium oxide and 3wt% yttrium oxide. The total coating thickness was 50±5μm.

[0093] Finally, it was polished with a diamond grinding wheel with a grain size of W5 until the roughness reached Ra0.2μm.

[0094] Comparative Example 3 purchased traditional steel rollers.

[0095] Experimental comparison

[0096] Test machine model: Zinser R71 ring spinning frame. In each round of experiment, one of the rollers of Example 1, Example 2, Comparative Example 1, Comparative Example 2, and Comparative Example 3 was applied to the equipment.

[0097] Experimental conditions: The spinning variety is C40S pure cotton yarn, and the spindle speed is 15000rpm.

[0098] Compared with Comparative Example 1, Example 1 shows a significant decrease in the end-down rate. This is because laser remelting significantly reduces porosity, lowering the coefficient of friction between the fiber and the roller surface, reducing static electricity accumulation and fiber adhesion. The CV value of Example 1 also decreases compared with Comparative Example 1. This is because the densified coating reduces the standard deviation of the nip pressure distribution from ±1.2N to ±0.3N, improving fiber control in the drafting zone and reducing the occurrence of thick and thin spots.

[0099] The rest of the detailed test results are shown in Table 1.

[0100] Table 1

[0101]

[0102] The pressure distribution test method in the drafting zone is to attach a pressure sensing film (Fujifilm Prescale) to the front roller jaws and collect the standard deviation of the pressure distribution within a length of 10 cm. The broken yarn rate is calculated based on 24 hours of continuous production (with strict control of the factory humidity: 28℃±1℃, humidity: 55%±5% RH). The CV value of the yarn is used. TESTER 6 instrument tests 500m of yarn (according to GB / T 3292.1 standard).

[0103] This shows that the coefficient of variation of the drafting zone pressure distribution of the present invention is less than 6%, and the end-breakage rate is less than 1.5 times per 1,000 spindles. The end-breakage rate is directly related to the drafting pressure distribution, and the end-breakage rate of Example 2 per 1,000 spindles is less than 1, reaching the international advanced level. The CV value of 13.6% is significantly lower than the industry standard for superior yarn (15.0%).

[0104] According to ASTM C633-13, the standard test method for the bond strength of thermal spray coatings, the interfacial bonding strength of Example 2 reached 58 MPa, while that of Example 1 was 32 MPa. The gradient deposition coating can prevent coating flaking during high-speed operation. Examples 1 and 2 were installed and put into production. Under fluctuating workshop temperatures (25°C to 50°C), the Example 1 coating developed microcracks approximately 50 μm after three weeks of service due to the difference in thermal expansion coefficients of ZrO2 / Y2O3, while the Example 2 coating showed no cracking.

[0105] Example 2, Comparative Example 1, and Comparative Example 3 were installed in three spinning frames and put into production. The maintenance difficulty and yarn quality of the three were compared. The results are shown in Table 2.

[0106] Table 2

[0107]

[0108] After long-term production of the rollers in Example 2, we found that they optimized the pressure distribution in the drafting zone of spinning frames, reducing front-zone pressure by approximately 15%. Our company previously used 2,000 steel rollers annually. Switching to nano-ceramic-coated rollers reduced this to just 600. Excluding costs such as plasma spraying and laser remelting, this resulted in an annual savings of 560,000 yuan. Furthermore, the end-down rate was lower than before, increasing production by 180 tons per year. Furthermore, the improved yarn evenness (CV) resulted in a 5% yarn premium, increasing revenue by 5.9 million yuan.

[0109] Throughout this specification, references to terms such as "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" indicate that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0110] 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 are also considered to be within the scope of protection of the present invention.

Claims

1. A roller with a nano-ceramic coating, characterized in that: The invention comprises a cylinder, the base material of which is 42CrMo alloy steel with a hardness of HRC28-32, the surface of the cylinder having a nitriding layer, and the cylinder being provided with a nano-ceramic coating on the nitriding layer, the porosity of the nano-ceramic coating being ≤1%, and the surface composition of the nano-ceramic coating comprising 95wt%-97wt% of zirconium oxide and 3wt%-5wt% of yttrium oxide.

2. The roller with nano-ceramic coating according to claim 1, characterized in that: The surface hardness is ≥1300HV, and the surface friction coefficient is 0.05~0.

07.

3. The roller with nano-ceramic coating according to claim 1, characterized in that: The nano ceramic coating comprises four stacked layers, which are in the following order from closest to the nitriding layer to farthest from the nitriding layer: The first layer contains 80 wt% zirconium oxide and 20 wt% yttrium oxide; The second layer contains 90 wt% zirconium oxide and 10 wt% yttrium oxide; The third layer contains 95 wt% zirconium oxide and 5 wt% yttrium oxide; The fourth layer contains 97 wt% zirconium oxide and 3 wt% yttrium oxide.

4. The roller with nano-ceramic coating according to claim 1 or 3, characterized in that: The thickness of the nano ceramic coating is 50±5 μm.

5. A method for manufacturing a roller with a nano-ceramic coating, characterized in that: The following steps are involved: The 42CrMo alloy steel with a hardness of HRC28 to 32 is machined into a cylinder; Performing ion nitriding treatment on the cylinder to form a nitrided layer on the surface of the cylinder; Depositing a nano-ceramic coating on the surface of the cylinder so that the surface composition of the nano-ceramic coating includes 95wt% to 97wt% of zirconium oxide and 3wt% to 5wt% of yttrium oxide; Laser remelting the nano-ceramic coating to make the porosity of the nano-ceramic coating ≤1%; The surface is polished to obtain the roller with the nano-ceramic coating.

6. The method for manufacturing a roller with a nano-ceramic coating according to claim 5, characterized in that: The ion nitriding treatment was performed at a temperature of 520° C. for 6 hours, forming a nitrided layer with a depth of 0.3 mm.

7. The method for manufacturing a roller with a nano-ceramic coating according to claim 5, characterized in that: In the step of depositing the nano ceramic coating on the surface of the cylinder, plasma spraying is adopted, the particle size D50 of the raw material powder is 80nm, and the specific surface area is ≥45m 2 / g; the spraying power is 34kW~52kW, and the powder feeding rate is 25g / min; the cylinder is preheated to 250±10℃ before receiving plasma spraying.

8. The method for manufacturing a roller with a nano-ceramic coating according to claim 7, characterized in that: In the step of depositing the nano-ceramic coating on the surface of the cylinder, the deposition is divided into four layers: In the first layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 80:20; In the second layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 90:10; In the third layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 95:5; In the fourth layer of raw materials, the mass ratio of zirconium oxide to yttrium oxide is 97:3; In the deposition order, the spray power of the next layer is reduced by 5% compared with the spray power of the previous layer.

9. The method for manufacturing a roller with a nano-ceramic coating according to claim 7, characterized in that: Before the step of depositing the nano-ceramic coating on the surface of the cylinder, the cylinder is pre-treated in the following order: Sandblasting until the surface roughness Ra reaches 3μm~4μm; Ultrasonic cleaning with organic solvents; The surface was bombarded with argon plasma at a power of 300 W for 5 min.

10. The method for manufacturing a roller with a nano-ceramic coating according to claim 5, characterized in that: In the laser remelting step, the laser wavelength is 1064 nm, the power is 800 W, the scanning speed is 12 mm / s, and the overlap rate is 40%.

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