Process method for high-density ceramic coating of chemical fiber spinning winding head forming plate

Abstract

The invention discloses a process method for a high-density ceramic coating of a chemical fiber spinning winding head forming plate. The method comprises the following steps that firstly, a formed plate base body is subjected to multiple times of abrasive belt polishing, and surface defects are removed; then sequentially carrying out ultrasonic cleaning with a dilute sulfuric acid solution, washing with tap water, rinsing with deionized water and drying with hot air; then nickel plating treatment is conducted, sand blasting is conducted through white corundum sand after nickel plating, and ultrasonic cleaning is conducted through acetone after sand blasting; mixing pure chromic oxide with specific granularity with titanium oxide powder to prepare spraying powder, and spraying with a plasma spray gun of which the rated power is greater than or equal to 40kW; stress is eliminated through stepped heating annealing after spraying; and finally, numerical control equipment and an electroplated diamond abrasive belt are used for polishing. According to the method, the porosity of the coating is smaller than or equal to 2.0%, the microhardness is larger than or equal to HV1000, the wear resistance of the formed plate is effectively improved, and the service life of the formed plate is effectively prolonged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of surface engineering and material processing technology, and specifically relates to a process method for high-density ceramic coating of a forming plate of a chemical fiber spinning winding head, which covers key technologies such as pretreatment of a metal substrate, special nickel plating, ceramic coating preparation, and post-treatment, and is suitable for surface strengthening and functional modification of core components of chemical fiber production equipment. BACKGROUND

[0002] In the chemical fiber spinning industry, the forming plate of the winding head is a key component that directly contacts the chemical fiber, and its surface performance directly affects the spinning quality and equipment life. Existing forming plates are mostly made of metal materials, but long-term use can cause problems such as wear, corrosion, and adhesion, leading to increased spinning surface defects and yarn breakage rate. To solve this problem, the industry generally uses ceramic coating technology to improve surface hardness and wear resistance.

[0003] However, the traditional ceramic coating process has the following defects: first, the substrate treatment process before coating preparation is simple, and there are residual impurities or oxide layers on the surface, which can cause insufficient adhesion between the coating and the substrate, and the coating can easily peel off; second, the control of ceramic powder particle size distribution and spraying parameters is rough, resulting in a high porosity and poor density of the formed coating, which cannot meet the stringent requirements of high-speed spinning for wear resistance; third, the conventional nickel plating process uses a single plating solution system, which has high internal stress and low hardness, and cannot provide a stable transition layer for the ceramic coating. In addition, the existing process lacks fine control in the polishing and annealing post-treatment stages, and it is difficult to achieve coordinated optimization of multiple properties such as coating surface roughness and microhardness. Therefore, there is an urgent need to develop a systematic high-density ceramic coating process to improve the reliability and production efficiency of chemical fiber spinning equipment SUMMARY

[0004] The present application focuses on the innovation design of a high-density ceramic coating process for the forming plate of the winding head of a chemical fiber spinning machine. Through multi-process coordinated optimization and parameter fine control, the problems of weak adhesion, high porosity, and insufficient wear resistance in traditional processes are systematically solved.

[0005] A process method for high-density ceramic coating of a forming plate of a chemical fiber spinning winding head, comprising the following steps: (1) Polishing treatment: multiple sand belt polishing treatments are performed on the surface of the forming plate substrate to remove surface defects; (2) Cleaning treatment: the polished forming substrate is sequentially cleaned with dilute sulfuric acid solution ultrasonic cleaning, flowing tap water rinsing, and deionized water overflow rinsing, and then dried with hot air to ensure that there are no water droplets remaining on the surface; (3) Electroplating treatment: the polished forming plate substrate is subjected to nickel plating treatment; (4) Sandblasting treatment: the nickel-plated forming plate substrate is subjected to white corundum sandblasting treatment, and then subjected to acetone ultrasonic cleaning after sandblasting is completed; (5) Coating material preparation: pure chromium oxide powder with fine particles and pure titanium oxide powder are mixed to form a spraying powder; (6) Plasma spraying: a plasma spraying gun is used to spray the shaped plate substrate after sand blasting treatment; (7) Annealing treatment: after coating spraying is completed, it is placed in a box-type resistance furnace for heating to eliminate stress; (8) Polishing treatment: using a numerical control device to polish the shaped plate after annealing using electroplated diamond abrasive belt polishing As preferred, the polishing treatment in step (1) is repeated for more than or equal to 3 times, and the surface roughness of the substrate is polished to less than or equal to 0.1 Ra. Through step-by-step grinding with different mesh sand belts, defects such as tool marks and micro-cracks generated during mechanical processing are removed, and a mirror surface substrate is formed. This step not only provides a flat surface for subsequent nickel plating, but also reduces the local stress concentration problem caused by uneven substrate of the coating, and improves the overall structural stability.

[0006] As preferred, the ultrasonic cleaning in step (2) is performed using a 2%-5% dilute sulfuric acid solution at 40-60°C, the ultrasonic frequency is set to 20-40 KHz, the cleaning time is 5-15 min; the flowing tap water flushing is performed at a water pressure of 0.2-0.3 MPa, a water temperature of normal temperature 10-30°C, and a cleaning time of 3-5 min; the deionized water overflow rinsing is performed with a water level higher than the workpiece by 10 cm, continuous water change, ultrasonic assistance, power 200-500 W, and duration 5-8 min; the hot air blowing is performed using a tunnel-type hot air drying oven, the temperature is set to 60-80°C, the air speed is 10-15 m / s, and the drying time is 10-30 min. The strong acidity of sulfuric acid reacts with metal oxides to dissolve the surface oxide film; the micro-jet generated by the ultrasonic cavitation effect at 20-40 KHz can penetrate into the micro-pores and strip stubborn impurities. Through mechanical scouring at a water pressure of 0.2-0.3 MPa, most of the sulfuric acid solution on the surface is quickly removed; then, the high-purity property of deionized water is used to completely remove residual acid ions and metal ions. With the assistance of ultrasonic, the cleaning effect of complex structure parts can be ensured, and defects such as coating pinholes and peeling caused by residual impurities can be avoided. The tunnel-type hot air drying oven is used to quickly evaporate the surface moisture without damaging the substrate at high temperature. This step not only prevents secondary oxidation caused by water stains, but also makes the substrate surface dry and active, providing ideal conditions for nickel plating reaction.

[0007] As preferred, the electroplating treatment in step (3) uses a horizontal electroplating tank, the tank body is made of PP material, the anode is an electrolytic nickel plate wrapped with a titanium basket, the purity is ≥99%; the plating solution composition is nickel methylsulfonate 280-320 g / L, boric acid 35-45 g / L, nickel chloride 5-8 g / L, sodium dodecyl sulfate 0.05-0.1 g / L, sodium propargyl sulfonate 0.5-1 g / L, hydroxyethylidene diphosphonic acid 0.1-0.3 mol / L, 30-50 nm nano Al2O3 0.5-2 g / L, and the plating solution PH is between 3.5-4.0; a double-pulse power supply is used, the pulse waveform is square wave, the forward pulse current density is set to 1.2-2.0 A / dm2, the pulse width is 5-10 ms, the reverse pulse current density is 0.5-1.0 A / dm2, the pulse width is 1-3 ms, and the pulse frequency is 500-1000 Hz; the electroplating temperature is maintained at 40-50°C, the electroplating time is 30-40 min, the cathode moves 5-10 times / min, and an air stirring device is used to continuously stir the plating solution; after the nickel plating is completed, immediately use deionized water to backwash more than 3 times to remove the residual plating solution, dry for standby use, the nickel layer thickness is >0.1 mm; the plating solution needs to be continuously ultrasonically circulated to prevent the nano particles from settling. The solubility of nickel methylsulfonate at 25°C is >500 g / L, which can significantly increase the Ni2+ ion concentration in the plating solution, reduce the solution resistance, and improve the current efficiency; in combination with the additives such as sodium propargyl sulfonate and hydroxyethylidene diphosphonic acid, uniform plating can be achieved on the surface of the complex-shaped forming plate; the addition of 30-50 nm nano Al2O3 particles is dispersed by ultrasonic circulation, so that they are uniformly embedded in the nickel layer; these nano particles act as "hard phase" to hinder dislocation movement, so as to improve the hardness of the plated layer, and at the same time provide micro anchor points for the ceramic coating to enhance the interlayer bonding; the forward pulse promotes the reduction and deposition of nickel ions, the reverse pulse dissolves the protrusions on the surface of the plated layer, forms a "growth-dissolution-regrowth" cycle, and the alternating current can offset part of the internal stress, so as to reduce the internal stress of the plated layer and avoid the cracking of the coating caused by stress concentration.

[0008] As preferred, the corner rounding rate of the chromium oxide powder in step (4) is ≥95%, and the sphericity of the titanium oxide powder is ≥90%; the sand blasting treatment uses 50-70 mesh white corundum sand to blast, so that the surface roughness reaches Ra2-3, and the residual thickness of the nickel layer after sand blasting is ≥0.08 mm; the acetone ultrasonic cleaning uses an acetone solution at 20-40°C as the cleaning liquid, the ultrasonic frequency is set to 20-40 KHz, the cleaning time is 5-15 min, the residual dust after sand blasting is removed, and after cleaning, the coating spraying process is entered. The white corundum sand is used to bombard the nickel-plated surface under the action of high-speed airflow to form a micron-level concave-convex structure, thereby increasing the mechanical interlocking area of the coating and the substrate; the acetone has strong dissolving capacity for organic pollutants such as grease, resin, and high-molecular polymer, can quickly penetrate and dissolve such pollutants through intermolecular forces, and when the ultrasonic wave propagates in the acetone solution, periodic pressure changes occur, forming countless micro cavitation bubbles. The instantaneous high pressure and high temperature generated when the bubbles burst can produce strong impact and stripping effects on the pollutants in the surface micro pores and grooves.

[0009] As preferred, the particle size distribution of the pure chromium oxide powder used in step (5) is D10: 10±2 μm, D50: 20±2 μm, and D90: 30±2 μm; the particle size distribution of the titanium oxide powder used is D10: 15±2 μm, D50: 30±2 μm, and D90: 45±2 μm; and the mixing ratio of the two is 50%: 50%-60%: 40%. The coating formula uses coarse and fine particles in combination to achieve “close packing”, thereby reducing the porosity of the coating, the chromium oxide provides high hardness, the titanium oxide enhances the chemical stability and lubricity, and the combination of the two can balance the wear resistance and anti-adhesion.

[0010] As preferred, the plasma gun spraying in step (6) uses a plasma gun with a rated power ≥40 kW, adopts a high-frequency inverter constant-current power supply, the current is 580-620 A, the voltage is 60-70 V, the primary gas flow is 38-40 LPM, the secondary gas flow is 6-7 LPM, the powder feeding amount is 25-35 g / min, the spraying distance is 65-80 mm, the coating thickness is 0.25-0.35 mm, and the porosity is ≤2.0%; the primary gas for the plasma spraying is argon with a purity ≥99.99%, and the secondary gas is a mixed gas of hydrogen with a purity ≥99.99% and helium with a purity ≥99.99%, and the volume ratio of hydrogen to helium is 7:3-8:2. The high-frequency power supply improves the arc stability and energy density, increases the plasma arc enthalpy value and particle speed; the argon primary gas enhances the enthalpy value to ensure the melting of high-melting-point materials, and the hydrogen-helium secondary gas provides a reducing atmosphere to inhibit oxidation; the parameters cooperatively reduce the residual stress, increase the coating bonding strength and microhardness, and significantly improve the wear resistance and service life of the forming plate.

[0011] As preferred, the annealing in step (7) adopts a vacuum annealing mode, the vacuum degree is maintained at 1×10-3 -1x10-2Pa, stepwise temperature rise, the first temperature rise stage is set at 100-150 DEG C, the second temperature rise stage is set at 150-200 DEG C, the temperature rise rate is 5-10 DEG C / min, the temperature drop rate is ≤1 DEG C / min, and the total duration is 3-5 hours.

[0012] Preferably, in the polishing treatment of step (8), multi-axis machining mode of numerical control equipment is used for polishing, through linkage of three linear axes X, Y and Z and two rotary axes, three-dimensional software editing program is used to preset the included angle between the side edge of the polishing wheel and the surface of the forming plate as 15 DEG to 25 DEG, and curved surface copying polishing is realized through dynamic posture adjustment, a torque sensor is added in grinding to adjust the polishing intensity in real time, the pressure fluctuation range is controlled within ±0.5 N, and the dynamic torque compensation coefficient is 0.8-1.2; the electroplated diamond abrasive belt polishing uses 400 mesh, 1000 mesh and 3000 mesh in sequence, the abrasive belt linear speed is 15-20 m / s, a water-based coolant is used for cooling, after polishing, the coating surface roughness is reduced to Rz1-2, the microhardness is greater than or equal to HV1000, the surface roughness is Ra1.0-1.8, and the glossiness is greater than or equal to 95GU. Through the polishing method, the surface roughness is reduced, the polishing pressure is accurately controlled, excessive grinding to cause coating thinning or damage is avoided, the performance such as hardness and bonding force is stable, and the demand of low friction surface for high-speed spinning is met.

[0013] In summary, the present application has the following beneficial effects: 1. Bonding strength: four-stage pretreatment of 'polishing-nano composite nickel plating-sand blasting-ultrasonic cleaning' is adopted, a nano-micro composite interface is constructed on the surface of the substrate, and the bonding strength is improved; 2. Compactness improvement: pulse plasma spraying is combined with optimized powder formula, and the optimized gas ratio parameters are used, so that the porosity of the coating is less than or equal to 2.0%; 3. Wear resistance: the nano composite nickel plating layer and the high hardness ceramic coating synergistically act, and the wear rate is reduced; 4. Performance synergy optimization: the innovative nickel methanesulfonate plating solution system is embedded with nano Al2O3 particles, the hardness of the nickel layer is improved, and the ceramic coating synergistically acts, so that the wear life of the forming plate is prolonged; the numerical control polishing combined with the torque sensor controls the surface roughness Rz to be 1-2 microns, the glossiness reaches 95GU, and the demand of high-speed spinning is met. DETAILED DESCRIPTION

[0014] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the specification, as long as the modifications are within the scope of the claims of the present application.

[0015] Example 1

[0016] Polishing treatment: 800 mesh, 1500 mesh, 3000 mesh 3 times of sand belt circulation polishing.

[0017] Cleaning treatment: Dilute sulfuric acid ultrasonic: 50℃, 4% sulfuric acid solution, 35kHz ultrasonic cleaning for 8min; Tap water flushing: 0.25MPa water pressure, 25℃ water temperature, flushing for 4min; Deionized water rinsing: water level higher than the workpiece 12cm, ultrasonic power 400W, rinsing for 6min; Hot air drying: tunnel furnace 75℃, wind speed 13m / s, drying for 20min.

[0018] Electroplating treatment: Plating solution composition: nickel methyl sulfonate 300g / L, boric acid 40g / L, nickel chloride 7g / L, nano Al2O3 1.2g / L, propargyl sodium sulfonate 0.8g / L, hydroxy ethylene diphosphonic acid 0.2mol / L; Double pulse parameters: forward 1.6A / dm²(pulse width 8ms), reverse 0.7A / dm²(pulse width 2ms), frequency 900Hz; Electroplating conditions: 48℃, electroplating for 36min, cathode moving 8times / min, air stirring; Post-treatment: deionized water countercurrent rinsing for 4 times.

[0019] Sand blasting treatment: Sand blasting: 60 mesh white corundum sand, sand blasting pressure 0.4MPa; Acetone ultrasonic cleaning: temperature 30℃, ultrasonic frequency 40kHz, time 10min.

[0020] Coating material preparation: Chromium oxide powder: D10=10μm, D50=20μm, D90=30μm; Titanium oxide powder: D10=15μm, D50=30μm, D90=45μm; Mixing ratio: chromium oxide: titanium oxide mass ratio = 55%:45%.

[0021] Plasma spraying: Equipment: 9M spray gun, rated power 45kW, high frequency inverter constant current power supply; Process parameters: current 610A, voltage 66V, main gas argon, flow rate 39LPM, secondary gas hydrogen: helium = 7.5:2.5, secondary gas 6.5LPM, powder feeding amount 31g / min, spraying distance 73mm; Annealing treatment: Vacuum degree 5×10 -3Pa, temperature ramping, 120℃ for 1h, ramping rate 8℃ / min; 180℃ for 1.5h, ramping rate 5℃ / min, cooling rate 1℃ / min to room temperature.

[0022] Polishing treatment: Polishing wheel angle 20°, torque compensation coefficient 1.0, using 400, 1000, 3000 mesh abrasive belt in turn, linear speed 18m / s, water-based coolant concentration 6%.

[0023] Example 2

[0024] Polishing treatment: using 800 mesh, 1500 mesh, 3000 mesh three times of abrasive belt circulation polishing.

[0025] Cleaning treatment: Dilute sulfuric acid ultrasonic: 50℃, 4% sulfuric acid solution, 35kHz ultrasonic cleaning for 8min; Tap water flushing: 0.25MPa water pressure, 25℃ water temperature, flushing for 4min; Deionized water rinsing: water level higher than the workpiece 12cm, ultrasonic power 400W, rinsing for 6min; Hot air drying: tunnel furnace 75℃, air speed 13m / s, drying for 20min.

[0026] Electroplating treatment: Plating solution composition: nickel methyl sulfonate 300g / L, boric acid 40g / L, nickel chloride 7g / L, nano Al2O3 1.8g / L, propargyl sodium sulfonate 0.8g / L, hydroxy ethylene diphosphonic acid 0.2mol / L; Double pulse parameters: forward 1.6A / dm²(pulse width 8ms), reverse 0.7A / dm²(pulse width 2ms), frequency 900Hz; Electroplating conditions: 48℃, electroplating for 38min, cathode moving 8times / min, air stirring; Post-treatment: deionized water countercurrent rinsing for 4times.

[0027] Sandblasting treatment: Sandblasting: 60 mesh white corundum sand, sandblasting pressure 0.4MPa; Acetone ultrasonic cleaning: temperature 30℃, ultrasonic frequency 40kHz, time 10min.

[0028] Coating material preparation: Chromium oxide powder: D10=10μm, D50=20μm, D90=30μm; Titanium oxide powder: D10=15μm, D50=30μm, D90=45μm; Mixing ratio: chromium oxide: titanium oxide mass ratio = 55%:45%.

[0029] Plasma spraying: Equipment: 9M spray gun, rated power 45kW, high-frequency inverter constant current power supply; Process parameters: current 610A, voltage 66V, main gas argon, flow rate 39LPM, secondary gas hydrogen:helium=7.5:2.5, secondary gas 6.5LPM, powder feeding amount 31g / min, spraying distance 73mm; Annealing treatment: Vacuum degree 5x10 -3 Pa, ladder heating, 120℃ for 1h, heating rate 8℃ / min, 180℃ for 1.5h, heating rate 5℃ / min, cooling rate 1℃ / min to room temperature.

[0030] Polishing treatment: Polishing wheel angle 20°, torque compensation coefficient 1.0, 400, 1000, 3000 mesh abrasive belt used in turn, linear speed 18m / s, water-based coolant concentration 6%.

[0031] Example 3

[0032] Polishing treatment: 800 mesh, 1500 mesh, 3000 mesh 3 times of abrasive belt cycle polishing.

[0033] Cleaning treatment: Dilute sulfuric acid ultrasonic: 50℃, 4% sulfuric acid solution, 35kHz ultrasonic cleaning for 8min; Tap water flushing: 0.25MPa water pressure, 25℃ water temperature, flushing for 4min; Deionized water rinsing: water level higher than the workpiece 12cm, ultrasonic power 400W, rinsing for 6min; Hot air drying: tunnel furnace 75℃, wind speed 13m / s, drying for 20min.

[0034] Electroplating treatment: Plating solution composition: nickel methylsulfonate 300g / L, boric acid 40g / L, nickel chloride 7g / L, nano Al2O3 1.2g / L, propargyl sodium sulfonate 0.8g / L, hydroxyethylidene diphosphonic acid 0.2mol / L; Double pulse parameters: forward 1.6A / dm²(pulse width 8ms), reverse 0.7A / dm²(pulse width 2ms), frequency 900Hz; Electroplating conditions: 48℃, electroplating for 36min, cathode moving 8times / min, air stirring; Post-treatment: deionized water countercurrent rinsing 4times.

[0035] Sand blasting treatment: Sand blasting: 60 mesh white corundum sand, sand blasting pressure 0.4MPa; Acetone ultrasonic cleaning: temperature 30℃, ultrasonic frequency 40kHz, time 10min.

[0036] Coating material preparation: Chromium oxide powder: D10 = 10 μm, D50 = 20 μm, D90 = 30 μm; Titanium oxide powder: D10 = 15 μm, D50 = 30 μm, D90 = 45 μm; Mixing ratio: chromium oxide: titanium oxide mass ratio = 55%:45%.

[0037] Plasma spraying: Equipment: 9M spray gun, rated power 45kW, high-frequency inverter constant current power supply; Process parameters: current 610A, voltage 66V, primary gas argon, flow rate 39LPM, secondary gas hydrogen:helium = 7.5:2.5, flow rate 6.5LPM, powder feed rate 28g / min, spraying distance 70mm; Annealing treatment: Vacuum degree 5×10 -3 Pa, step heating, 120℃ for 1h, heating rate 8℃ / min; 180℃ for 1.5h, heating rate 5℃ / min, cooling rate 1℃ / min to room temperature.

[0038] Polishing: The throwing wheel angle is 20°, the torque compensation coefficient is 1.0, 400, 1000, and 3000 mesh abrasive belts are used in sequence, the linear speed is 18 m / s, and the concentration of water-based coolant is 6%.

[0039] Example 4

[0040] Polishing: Use 800 mesh, 1500 mesh, 3000 mesh sand belt for 3 cycles of polishing.

[0041] Cleaning treatment: Dilute sulfuric acid ultrasonic cleaning: 50℃, 4% sulfuric acid solution, 35kHz ultrasonic cleaning for 8 minutes; Tap water flushing: 0.25MPa water pressure, 25℃ water temperature, flushing for 4min; Deionized water rinsing: water level 12 cm above the workpiece, ultrasonic power 400 W, rinsing for 6 minutes; Hot air drying: tunnel oven 75℃, wind speed 13m / s, drying for 20min.

[0042] Electroplating treatment: Plating solution ingredients: nickel methanesulfonate 300g / L, boric acid 40g / L, nickel chloride 7g / L, nano-Al2O3 1.2g / L, sodium propargyl sulfonate 0.8g / L, hydroxyethylene diphosphonic acid 0.2mol / L; Double pulse parameters: 1.6 A / dm2 (pulse width 8 ms) in forward direction, 0.7 A / dm2 (pulse width 2 ms) in reverse direction, frequency 900 Hz; Electroplating conditions: 48°C, electroplating for 36 min, cathode moving 8 times / min, air agitation; Post-treatment: deionized water counter-flow rinsing for 4 times.

[0043] Sand blasting treatment: Sand blasting: 60-mesh white corundum sand, sand blasting pressure 0.4 MPa; Acetone ultrasonic cleaning: temperature 30°C, ultrasonic frequency 40 kHz, time 10 min.

[0044] Coating material preparation: Chromium oxide powder: D10=10 μm, D50=20 μm, D90=30 μm; Titanium oxide powder: D10=15 μm, D50=30 μm, D90=45 μm; Mixing ratio: chromium oxide: titanium oxide mass ratio = 55%:45%.

[0045] Plasma spraying: Equipment: 9M spray gun, rated power 45 kW, high-frequency inverter constant-current power supply; Process parameters: current 610 A, voltage 66 V, main gas argon, flow rate 39 LPM, secondary gas hydrogen:helium = 7.5:2.5, flow rate 6.5 LPM, powder feeding amount 31 g / min, spraying distance 73 mm; Annealing treatment: Vacuum degree 5×10 -3 Pa, ladder heating, 100°C for 1.5 h, 150°C for 1 h, 200°C for 0.5 h, heating rate 5°C / min, cooling rate 1°C / min to room temperature.

[0046] Polishing treatment: Polishing wheel included angle 20°, torque compensation coefficient 1.0, 400, 1000, 3000-mesh abrasive belts are used in sequence, linear speed 18 m / s, water-based coolant concentration 6%.

[0047] Comparative Example 1

[0048] Polishing treatment: 800-mesh, 1500-mesh, 3000-mesh three-time abrasive belt circulation polishing.

[0049] Cleaning treatment: Dilute sulfuric acid ultrasonic: 50°C, 4% sulfuric acid solution, 35 kHz ultrasonic cleaning for 8 min; Tap water flushing: 0.25 MPa water pressure, 25°C water temperature, flushing for 4 min; Deionized water rinsing: water level 12 cm higher than workpiece, ultrasonic power 400 W, rinsing 6 min; Hot air blowing: tunnel furnace 75℃, air speed 13 m / s, drying 20 min.

[0050] Electroplating treatment: Plating solution composition: nickel methylsulfonate 300 g / L, boric acid 40 g / L, nickel chloride 7 g / L, nano-Al2O3 1.2 g / L, sodium propargyl sulfonate 0.8 g / L, hydroxyethylidene diphosphonic acid 0.2 mol / L; Double pulse parameters: forward 1.6 A / dm2(pulse width 8 ms), reverse 0.7 A / dm2(pulse width 2 ms), frequency 900 Hz; Electroplating conditions: 48℃, electroplating 36 min, cathode moving 8 times / min, air stirring; Post-treatment: deionized water countercurrent rinsing 4 times.

[0051] Sand blasting treatment: Sand blasting: 60-mesh white corundum sand, sand blasting pressure 0.4 MPa; No acetone ultrasonic cleaning is performed.

[0052] Coating material preparation: Chromium oxide powder: D10=10 μm, D50=20 μm, D90=30 μm; Titanium oxide powder: D10=15 μm, D50=30 μm, D90=45 μm; Mixing ratio: chromium oxide: titanium oxide mass ratio = 55%:45%.

[0053] Plasma spraying: Equipment: 9M spray gun, rated power 45 kW, high-frequency inverter constant current power supply; Process parameters: current 610 A, voltage 66 V, main gas argon, flow rate 39 LPM, secondary gas hydrogen: helium = 7.5:2.5, flow rate 6.5 LPM, powder feeding amount 33 g / min, spraying distance 70 mm; Annealing treatment: Vacuum degree 5×10 -3 Pa, stepwise heating, 120℃ for 1 h, heating rate 8℃ / min; 180℃ for 1.5 h, heating rate 5℃ / min, cooling rate 1℃ / min to room temperature.

[0054] Polishing treatment: Polishing wheel included angle 20°, torque compensation coefficient 1.0, 400, 1000, 3000-mesh abrasive belts are used in sequence, linear speed 18 m / s, water-based coolant concentration 6%.

[0055] Comparative Example 2

[0056] Polishing treatment: 3 times of sand belt cycle polishing with 800 mesh, 1500 mesh and 3000 mesh.

[0057] Cleaning treatment: Dilute sulfuric acid ultrasonic: 50℃, 4% sulfuric acid solution, 35kHz ultrasonic cleaning for 8min; Tap water flushing: 0.25MPa water pressure, 25℃ water temperature, flushing for 4min; Deionized water rinsing: water level higher than workpiece by 12cm, ultrasonic power 400W, rinsing for 6min; Hot air drying: tunnel furnace 75℃, air speed 13m / s, drying for 20min.

[0058] Electroplating treatment: Plating solution composition: nickel sulfamate 320g / L, boric acid 40g / L, nickel chloride 10g / L, sodium dodecyl sulfate 0.1g / L; Single pulse parameters: current 1.8A / dm², pulse width 10ms, frequency 500Hz; Electroplating conditions: 45℃, electroplating for 40min, cathode moving 8 times / min, air stirring; Post-treatment: deionized water countercurrent rinsing 4 times.

[0059] Sand blasting treatment: Sand blasting: 60 mesh white corundum sand, sand blasting pressure 0.4MPa; Acetone ultrasonic cleaning: temperature 30℃, ultrasonic frequency 40kHz, time 10min.

[0060] Coating material preparation: Chromium oxide powder: D10=10μm, D50=20μm, D90=30μm; Titanium oxide powder: D10=15μm, D50=30μm, D90=45μm; Mixing ratio: chromium oxide: titanium oxide mass ratio = 55%:45%.

[0061] Plasma spraying: Equipment: 9M spray gun, rated power 45kW, high-frequency inverter constant-current power supply; Process parameters: current 610A, voltage 66V, main gas argon, flow rate 39LPM, secondary gas hydrogen: helium = 7.5:2.5, flow rate 6.5LPM, powder feeding amount 31g / min, spraying distance 73mm; Annealing treatment: Vacuum degree 5×10 -3Pa, temperature ramping, 120℃ for 1h, ramping rate 8℃ / min; 180℃ for 1.5h, ramping rate 5℃ / min, cooling rate 1℃ / min to room temperature.

[0062] Polishing treatment: Polishing wheel angle 20°, torque compensation coefficient 1.0, using 400, 1000, 3000 mesh abrasive belt in turn, linear speed 18m / s, water-based coolant concentration 6%.

[0063] Comparative Example 3

[0064] Polishing treatment: using 800 mesh, 1500 mesh, 3000 mesh three times of abrasive belt circulation polishing.

[0065] Cleaning treatment: Dilute sulfuric acid ultrasonic: 50℃, 4% sulfuric acid solution, 35kHz ultrasonic cleaning for 8min; Tap water flushing: 0.25MPa water pressure, 25℃ water temperature, flushing for 4min; Deionized water rinsing: water level higher than workpiece 12cm, ultrasonic power 400W, rinsing for 6min; Hot air drying: tunnel furnace 75℃, air speed 13m / s, drying for 20min.

[0066] Electroplating treatment: Plating solution composition: nickel methylsulfonate 300g / L, boric acid 40g / L, nickel chloride 7g / L, nano Al2O3 1.2g / L, propargyl sodium sulfonate 0.8g / L, hydroxy ethylene diphosphonic acid 0.2mol / L; Double pulse parameters: forward 1.6A / dm²(pulse width 8ms), reverse 0.7A / dm²(pulse width 2ms), frequency 900Hz; Electroplating conditions: 48℃, electroplating for 36min, cathode moving 8times / min, air stirring; Post-treatment: deionized water countercurrent rinsing for 4times.

[0067] Sandblasting treatment: Sandblasting: 60 mesh white corundum sand, sandblasting pressure 0.4MPa; Acetone ultrasonic cleaning: temperature 30℃, ultrasonic frequency 40kHz, time 10min.

[0068] Coating material preparation: Chromium oxide powder: D10=10μm, D50=20μm, D90=30μm; Titanium oxide powder: D10=15μm, D50=30μm, D90=45μm; Mixing ratio: chromium oxide: titanium oxide mass ratio = 55%:45%.

[0069] Plasma spraying: Equipment: 9M spray gun, rated power 45kW, high-frequency inverter constant-current power supply; Process parameters: current 610A, voltage 66V, main gas argon, flow rate 39LPM, secondary gas hydrogen: helium = 7.5:2.5, flow rate 6.5LPM, powder feeding amount 31g / min, spraying distance 73mm; Annealing treatment: Vacuum degree 5x10 -3 Pa, ladder heating, 120℃ for 1h, heating rate 8℃ / min, 180℃ for 1.5h, heating rate 5℃ / min, cooling rate 1℃ / min to room temperature.

[0070] Polishing treatment: Use 400 mesh, 1000 mesh, 3000 mesh abrasive belt, operate by skilled workers with hand-held polishing machine, polishing wheel angle about 30°, total polishing time 40min, artificial judge polishing degree, no cooling liquid is used.

[0071] Test data:

[0072] Experimental conclusion: Porosity and density: Example 3, the pulse frequency is increased to 150Hz, the porosity is reduced to 1.3%, lower than Example 1, confirming the significant effect of high-frequency pulse on coating densification.

[0073] Wear resistance and thermal stability: Example 4, the thermal cycle number reaches 1600 times by stage annealing, the wear amount is reduced to 0.012mm, indicating the optimization effect of stage annealing on stress release.

[0074] Surface precision: Example 3 cooperates with numerical control polishing to reduce Rz to 1.1μm, verifying the synergistic effect of process parameters and post-processing.

[0075] Interface cleaning necessity: Example 1 omits the acetone ultrasonic cleaning step, the bonding strength is reduced, the porosity is increased to 3.2%, confirming that the surface contaminants after sandblasting are the main cause of interface failure.

[0076] Plating solution system innovation: Example 2 uses traditional sulfamate plating solution, the coating wear resistance is significantly attenuated compared with Example 1, highlighting the strengthening advantage of nickel methyl sulfonate + nano Al2O3 system.

[0077] Polishing process advancement: Example 3, traditional manual polishing makes the surface roughness Rz standard deviation reach 0.8μm, Example 1 is 0.15μm, verifying the key role of numerical control five-axis polishing in uniformity of complex surface.

[0078] Summary: Through multi-parameter synergistic improvement, such as nanoparticle addition, pulse spraying, step annealing and other innovations, the performance combination of improved bonding strength, reduced porosity and reduced wear and tear is achieved, which is more comprehensive than traditional processes. Parameter interval design covers equipment, which can reduce performance standard deviation, improve yield in mass production, and meet the needs of large-scale production.

[0079] The process of the application has been optimized through multi-parameter synergy, and the core indicators of porosity, bonding strength and wear life have been improved, providing a quantifiable solution for the long life of key components of chemical fiber spinning equipment.

Claims

1. A process for high-density ceramic coating of a chemical fiber spinning winder forming plate, characterized in that: The following steps are involved: (1) Polishing: The surface of the formed plate substrate is polished with abrasive belts multiple times to remove surface defects; (2) Cleaning: The polished molded substrate is ultrasonically cleaned with a dilute sulfuric acid solution, rinsed with running tap water, and then rinsed with deionized water overflow. After cleaning, it is dried with hot air to ensure that no water droplets remain on the surface. (3) Electroplating treatment: nickel plating the polished molded plate substrate; (4) Sandblasting: The nickel-plated molded plate substrate is sandblasted with white corundum sand, and then cleaned with acetone ultrasonic cleaning; (5) Preparation of coating materials: Fine-grained pure chromium oxide powder that has been melted, crushed, and de-edged is mixed with melted, crushed pure titanium oxide powder to make spray powder; (6) Plasma spraying: Use a plasma spray gun to spray the coating on the formed plate substrate after sandblasting; (7) Annealing treatment: After the coating is sprayed, it is placed in a box-type resistance furnace for heating to anneal and eliminate stress; (8) Polishing: Use CNC equipment to polish the annealed formed plate using electroplated diamond abrasive belt.

2. The process for high-density ceramic coating of a chemical fiber spinning winder forming plate according to claim 1, characterized in that: In the polishing treatment described in step (1), the number of sand belt circulation polishing is ≥3 times, and the surface roughness of the substrate is polished to below Ra0.

1.

3. The process for high-density ceramic coating of a chemical fiber spinning winder forming plate according to claim 1, characterized in that: In step (2), the ultrasonic cleaning with dilute sulfuric acid solution is a 2%-5% dilute sulfuric acid solution at 40-60°C, the ultrasonic frequency is set to 20-40KHz, and the cleaning time is 5-15min; the running tap water flushing is performed with a water pressure of 0.2-0.3MPa, a water temperature of room temperature 10-30°C, and a cleaning time of 3-5min; the overflow rinsing with deionized water is performed with a water level 10cm higher than the workpiece, the water is continuously changed, and ultrasonic assistance is used with a power of 200-500W and a duration of 5-8min; the hot air drying is performed using a tunnel-type hot air drying oven with a temperature setting of 60-80°C, a wind speed of 10-15m / s, and a drying time of 10-30min.

4. The process for high-density ceramic coating of a forming plate of a chemical fiber spinning winder according to claim 1, characterized in that: The electroplating treatment in step (3) uses a horizontal electroplating tank, the tank body is made of PP material, the anode is an electrolytic nickel plate wrapped with a titanium basket, and the purity is ≥99%; the plating solution composition is 280-320g / L of nickel methanesulfonate, 35-45g / L of boric acid, 5-8g / L of nickel chloride, 0.05-0.1g / L of sodium lauryl sulfate, 0.5-1g / L of sodium propargyl sulfonate, 0.1-0.3mol / L of hydroxyethylidene diphosphonic acid, 0.5-2g / L of 30-50nm nano-Al2O3, and the pH of the plating solution is between 3.5-4.0; a dual pulse power supply is used, the pulse waveform is a square wave, and the positive pulse is The impulse current density is set to 1.2-2.0A / dm², the pulse width is 5-10ms, the reverse pulse current density is 0.5-1.0A / dm², the pulse width is 1-3ms, and the pulse frequency is 500-1000HZ; the electroplating temperature is maintained at 40-50℃, the electroplating time is 30-40min, the cathode moves 5-10 times / min, and the plating solution is continuously stirred with an air stirring device; after nickel plating is completed, it is immediately rinsed with deionized water in reverse for more than 3 times to remove residual plating solution, and dried for use. The nickel layer thickness is greater than 0.1mm; the plating solution needs to be continuously ultrasonically circulated to prevent the sedimentation of nanoparticles.

5. The process for high-density ceramic coating of a chemical fiber spinning winder forming plate according to claim 1, characterized in that: In step (4), the angular passivation rate of the chromium oxide powder is ≥95%, and the sphericity of the titanium oxide powder is ≥90%; the sandblasting treatment uses 50-70 mesh white corundum sand to make the surface roughness reach Ra2-3, and the residual thickness of the nickel layer after sandblasting is ≥0.08mm; the acetone ultrasonic cleaning uses an acetone solution at 20-40°C as the cleaning liquid, the ultrasonic frequency is set to 20-40KHz, and the cleaning time is 5-15min to remove the residual dust from the sandblasting. After the cleaning is completed, the coating spraying process is started.

6. The process for high-density ceramic coating of a chemical fiber spinning winder forming plate according to claim 1, characterized in that: The particle size distribution of the pure chromium oxide powder used in step (5) is D10: 10±2μm, D50: 20±2μm, D90: 30±2μm; the particle size distribution of the titanium oxide powder used is D10: 15±2μm, D50: 30±2μm, D90: 45±2μm; and the mixing ratio of the two is 50%:50%-60%:40%.

7. The process for high-density ceramic coating of a forming plate of a chemical fiber spinning winder according to claim 1, characterized in that: The plasma gun spraying in step (6) uses a plasma spray gun with a rated power of ≥40kW, a high-frequency inverter constant current power supply, a current of 580-620A, a voltage of 60-70V, a main gas flow rate of 38-40LPM, a secondary gas flow rate of 6-7LPM, a powder feed rate of 25-35g / min, a spraying distance of 65-80mm, a coating thickness of 0.25-0.35mm, and a porosity of ≤2.0%; the main gas for the plasma spraying is argon with a purity of ≥99.99%, and the secondary gas is a mixed gas of hydrogen with a purity of ≥99.99% and helium with a purity of ≥99.99%, with a volume ratio of hydrogen:helium = 7:3-8:

2.

8. The process for high-density ceramic coating of a forming plate of a chemical fiber spinning winder according to claim 1, characterized in that: The annealing in step (7) is performed by vacuum annealing, and the vacuum degree is maintained at 1×10 -3 -1×10 -2 Pa, step-by-step heating, the temperature of the first heating stage is set at 100-150℃, the temperature of the second heating stage is set at 150-200℃, the heating rate is 5-10℃ / min, the cooling rate is ≤1℃ / min, and the total duration is 3-5 hours.

9. The process for high-density ceramic coating of a forming plate of a chemical fiber spinning winder according to claim 1, characterized in that: In the polishing process of step (8), the multi-axis processing method of the numerical control equipment is adopted for polishing. Through the linkage of the three linear axes X, Y, and Z and the two rotation axes, the three-dimensional software editing program is used to preset the angle between the side edge of the polishing wheel and the surface of the forming plate to 15°-25°, and the curved surface profiling polishing is achieved by dynamic posture adjustment. A torque sensor is added during grinding to adjust the polishing force in real time. The pressure fluctuation range is controlled within ±0.5N, and the dynamic torque compensation coefficient is 0.8-1.2; the electroplated diamond belt polishing uses 400 mesh, 1000 mesh, and 3000 mesh in sequence, with a belt linear speed of 15-20m / s and cooling with a water-based coolant. After polishing, the surface roughness of the coating is reduced to Rz1-2, the microhardness is ≥HV1000, the surface roughness is Ra0.05-0.2, and the glossiness is ≥95GU.

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