Surface processing method of metal parts

Abstract

The present invention relates to the field of metal processing technology, and discloses a surface processing method for metal parts using the following technical scheme: S1, pretreatment; cleaning, stress relief annealing; S2, surface micronization treatment; shot peening; electrochemical polishing; S3, surface modification treatment; ion implantation; laser surface treatment; S4, post-treatment; cleaning and testing. Pretreatment removes impurities and internal stress on the surface of parts, avoiding the risk of deformation during processing, and then surface micronization treatment significantly reduces the surface roughness, allowing the surface to achieve a mirror or near-mirror effect, thereby improving the aesthetics and assembly accuracy of parts.

Description

Technical Field

[0001] The invention relates to the field of metal processing, in particular to a surface processing method for metal parts. Background Art

[0002] Metal parts play a vital role in many industrial fields, and their performance and service life are often closely related to their surface quality. However, existing surface processing methods for metal parts have many shortcomings. Traditional mechanical processing methods, such as grinding and turning, can change the size and surface shape of parts, but they often leave obvious processing textures on the surface after processing, resulting in large surface roughness, affecting the aesthetics of the parts and the subsequent assembly accuracy. Moreover, for some metal parts with complex shapes, these processing methods are difficult to ensure that all parts can achieve uniform processing effects, and local over- or under-processing is prone to occur.

[0003] Chemical etching methods are also used in metal surface processing, but they have problems such as large amounts of chemical reagents used and high risks of environmental pollution. In addition, the etching process is difficult to control accurately and can easily cause excessive corrosion to the substrate of metal parts, affecting their overall performance and structural integrity.

[0004] In addition, some existing surface treatment processes, such as electroplating and spraying, mainly focus on adding a coating to the metal surface to improve corrosion resistance or aesthetics, but the bonding strength between the coating and the metal substrate is limited. When used for a long time or subjected to external forces, the coating is easy to fall off, and the surface quality of the parts cannot be guaranteed in the long term. Therefore, the present invention proposes a surface processing method for metal parts to solve the above problems. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a surface processing method for a metal component.

[0006] The present invention provides a surface processing method for metal parts using the following technical solution:

[0007] S1. Preprocessing

[0008] Cleaning: Place the metal parts to be processed into an ultrasonic cleaning device, use an aqueous solution containing an appropriate amount of metal cleaning agent as the cleaning solution, clean for 10-30 minutes at an ultrasonic frequency of 20-50 kHz, then rinse with clean water and dry;

[0009] Stress relief annealing: Place the cleaned metal parts in the annealing furnace and select the appropriate annealing temperature and time according to the material of the parts for stress relief annealing;

[0010] S2. Surface micronization

[0011] Shot peening: Select the projectiles with appropriate particle size, use the shot peening equipment to spray the projectiles onto the surface of the parts with 0.3-0.8MPa compressed air pressure, and the shot peening time is controlled within 5-20 minutes according to the size and complexity of the parts;

[0012] Electrochemical polishing: Place the shot-peened parts as the anode in an electrochemical polishing tank filled with a specific electrolyte, and use a stainless steel plate as the cathode. Control the current density at 10-50A / dm², the electrolysis temperature at 40-80℃, and the electrolysis time for 3-15 minutes.

[0013] S3. Surface modification

[0014] Ion implantation: Use ion implantation equipment, select appropriate implantation ions, and place them under vacuum at 10 -3 - 10 -5 Pa, ions are implanted into the treated surface of the component with an energy of 50-200keV, and the implantation dose is controlled at 1×10 15 -1×10 18 ions / cm²;

[0015] Laser surface treatment: Use laser processing equipment to select a laser beam with appropriate wavelength and power to scan the surface of the parts after ion implantation. The scanning speed is controlled at 5-50 mm / s and the spot diameter is set at 0.5-5mm.

[0016] S4. Post-processing

[0017] Cleaning and testing: Place the metal parts that have undergone the above treatment into the ultrasonic cleaning equipment again and use deionized water to clean them for 5-15 minutes to remove residual electrolyte and impurities on the surface. Then use surface roughness testers, hardness testers, metallographic microscopes and other testing equipment to test the surface roughness, hardness and microstructure of the parts.

[0018] Preferably, the mass fraction of the metal cleaning agent in the cleaning liquid is 3%-5%.

[0019] Preferably, in the stress relief annealing of the pretreatment step, the annealing temperature of carbon steel is 550-650°C, and the insulation time is 1-3 hours; the annealing temperature of alloy steel is 600-700°C, and the insulation time is 2-4 hours; the annealing temperature of aluminum alloy is 200-400°C, and the insulation time is 1-2 hours.

[0020] Preferably, in the shot peening of the surface refinement treatment step, the particle size of the shot is 0.2-1.5 mm, and the shot is stainless steel shot or ceramic shot.

[0021] Preferably, in the electrochemical polishing of the surface refinement treatment step, for parts made of stainless steel, the electrolyte is a mixed electrolyte consisting of phosphoric acid, sulfuric acid and chromic acid.

[0022] Preferably, in the ion implantation in the surface modification step, the implanted ions are nitrogen ions or titanium ions.

[0023] Preferably, in the laser surface treatment in the surface modification step, the wavelength of the laser beam is 1064nm, 532nm, and the power is 500-50.

[0024] In summary, the present invention includes at least one of the following beneficial technical effects:

[0025] 1. Improve surface quality: Pre-treatment removes impurities and internal stress on the surface of parts and components, avoiding the risk of deformation during processing. Surface micro-processing significantly reduces surface roughness, allowing the surface to achieve a mirror or near-mirror effect, improving the aesthetics and assembly accuracy of parts and components.

[0026] 2. Enhanced surface performance: The surface modification method combining ion implantation and laser surface treatment effectively improves the hardness, wear resistance, corrosion resistance and oxidation resistance of the surface of parts, extends the service life of parts, and enables them to better adapt to harsh working environments.

[0027] 3. Good environmental protection: Compared with the traditional chemical etching method, the present invention reduces the use of a large number of chemical reagents during the processing process, and the generated wastewater, waste gas and other pollutants can be effectively treated by conventional environmental protection treatment methods, reducing the risk of environmental pollution and meeting the requirements of modern green manufacturing.

[0028] 4. Strong versatility: The processing method of the present invention is applicable to metal parts of various materials (such as carbon steel, alloy steel, aluminum alloy, stainless steel, etc.) and different shapes (simple to complex shapes). High-quality surface processing effects can be achieved by properly adjusting the process parameters according to the specific metal type and parts characteristics.

[0029] 5. Improve the adhesion of coatings: The surface of metal parts treated by the present invention is optimized in terms of both microstructure and stress state. DETAILED DESCRIPTION

[0030] The present invention is described in further detail below.

[0031] Embodiment 1:

[0032] Take a certain type of stainless steel mechanical part as an example. The shape of the part is relatively complex, with dimensions of 100mm in length, 50mm in width, and 30mm in height. The specific steps for surface processing are as follows:

[0033] Preprocessing

[0034] Cleaning: Place the stainless steel part in an ultrasonic cleaning device, use an aqueous solution containing 5% (mass fraction) of metal cleaning agent as the cleaning solution, clean it for 20 minutes at an ultrasonic frequency of 30kHz, then rinse it with clean water and dry it.

[0035] Stress relief annealing: Place the cleaned parts in an annealing furnace, set the annealing temperature to 600°C, and keep it warm for 2 hours for stress relief annealing.

[0036] Surface micro-refining

[0037] Shot peening: Select stainless steel shot with a particle size of 0.5 mm, and use shot peening equipment to spray the shot onto the surface of the part with a compressed air pressure of 0.5 MPa. The shot peening time is 10 minutes.

[0038] Electrochemical polishing: The shot peened parts are used as anodes in an electrochemical polishing tank filled with a mixed electrolyte consisting of phosphoric acid, sulfuric acid and chromic acid in a volume ratio of 1:1:0.5. The stainless steel plate is used as the cathode. The current density is controlled at 30A / dm², the electrolysis temperature is 60℃, and the electrolysis time is 8 minutes.

[0039] Surface modification

[0040] Ion implantation: Use ion implantation equipment, select nitrogen ions as the implanted ions, and use a vacuum of 10 -4 Pa, ions were implanted into the treated surface of the part with an energy of 100 keV, and the implantation dose was controlled at 5×10 16 ions / cm².

[0041] Laser surface treatment: Using laser processing equipment, select a laser beam with a wavelength of 1064nm and a power of 2000W to scan the surface of the parts after ion implantation. The scanning speed is controlled at 20mm / s and the spot diameter is set at 2mm.

[0042] Post-processing

[0043] Cleaning and testing: The parts that have undergone the above treatment are placed in the ultrasonic cleaning equipment again and cleaned with deionized water for 10 minutes. Then, the surface roughness, hardness, microstructure, etc. of the parts are tested using surface roughness testers, hardness testers, metallographic microscopes and other testing equipment. The test results show that the surface roughness Ra reaches 0.05μm, the surface hardness is increased by about 30% compared with before processing, and the microstructure is dense and uniform, meeting the expected processing requirements.

[0044] Embodiment 2:

[0045] Take a certain type of aluminum alloy automobile parts as an example. The parts are irregular in shape and of different sizes. The maximum length is about 200mm. The specific steps for surface processing are as follows:

[0046] Preprocessing

[0047] Cleaning: Place the aluminum alloy part in an ultrasonic cleaning device, use an aqueous solution containing 3% (mass fraction) of metal cleaning agent as the cleaning liquid, clean it for 15 minutes at an ultrasonic frequency of 40kHz, then rinse it with clean water and dry it.

[0048] Stress relief annealing: Place the cleaned parts in an annealing furnace, set the annealing temperature to 300°C, and keep it warm for 1.5 hours for stress relief annealing.

[0049] Surface micro-refining

[0050] Shot peening: Ceramic shot with a particle size of 0.8 mm was selected, and the shot was sprayed onto the surface of the part using a shot peening device with a compressed air pressure of 0.6 MPa. The shot peening time was 15 minutes.

[0051] Electrochemical polishing: The shot peened parts are used as anodes in an electrochemical polishing tank filled with an electrolyte specifically for aluminum alloys (the main components include phosphoric acid, oxalic acid, etc.), and a stainless steel plate is used as the cathode. The current density is controlled at 20A / dm², the electrolysis temperature is 50°C, and the electrolysis time is 10 minutes.

[0052] Surface modification

[0053] Ion implantation: Use ion implantation equipment, select titanium ions as the implanted ions, and use a vacuum of 10 -5 Pa, ions were implanted into the treated surface of the part with an energy of 150keV, and the implantation dose was controlled at 8×10 16 ions / cm².

[0054] Laser surface treatment: Using laser processing equipment, select a laser beam with a wavelength of 532nm and a power of 3000W to scan the surface of the parts after ion implantation. The scanning speed is controlled at 30mm / s and the spot diameter is set at 3mm.

[0055] Post-processing

[0056] Cleaning and testing: The parts that have undergone the above treatment are placed in the ultrasonic cleaning equipment again and cleaned with deionized water for 12 minutes. Then, the surface roughness, hardness, microstructure, etc. of the parts are tested using surface roughness testers, hardness testers, metallographic microscopes and other testing equipment. The test results show that the surface roughness Ra reaches 0.08μm, and the surface hardness is increased by about 25% compared with before processing. The microstructure is dense and uniform, which meets the expected processing requirements.

[0057] It should be noted that, in this article, terms such as "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A surface processing method for a metal part, characterized in that: The steps include: S1. Preprocessing Cleaning: Place the metal parts to be processed into an ultrasonic cleaning device, use an aqueous solution containing an appropriate amount of metal cleaning agent as the cleaning solution, clean for 10-30 minutes at an ultrasonic frequency of 20-50 kHz, then rinse with clean water and dry; Stress relief annealing: Place the cleaned metal parts in the annealing furnace and select the appropriate annealing temperature and time according to the material of the parts for stress relief annealing; S2. Surface micronization Shot peening: Select the projectiles with appropriate particle size, use the shot peening equipment to spray the projectiles onto the surface of the parts with 0.3-0.8MPa compressed air pressure, and the shot peening time is controlled within 5-20 minutes according to the size and complexity of the parts; Electrochemical polishing: Place the shot-peened parts as the anode in an electrochemical polishing tank filled with a specific electrolyte, and use a stainless steel plate as the cathode. Control the current density at 10-50A / dm², the electrolysis temperature at 40-80℃, and the electrolysis time for 3-15 minutes. S3. Surface modification Ion implantation: Use ion implantation equipment, select appropriate implantation ions, and place them under vacuum at 10 -3 - 10 -5 Pa, ions are implanted into the treated surface of the component with an energy of 50-200keV, and the implantation dose is controlled at 1×10 15 -1×10 18 ions / cm²; Laser surface treatment: Use laser processing equipment to select a laser beam with appropriate wavelength and power to scan the surface of the parts after ion implantation. The scanning speed is controlled at 5-50 mm / s and the spot diameter is set at 0.5-5mm. S4. Post-processing Cleaning and testing: Place the metal parts that have undergone the above treatment into the ultrasonic cleaning equipment again and use deionized water to clean them for 5-15 minutes to remove residual electrolyte and impurities on the surface. Then use surface roughness testers, hardness testers, metallographic microscopes and other testing equipment to test the surface roughness, hardness and microstructure of the parts.

2. The surface processing method of a metal component according to claim 1, characterized in that: The mass fraction of the metal cleaning agent in the cleaning solution is 3%-5%.

3. The surface processing method of a metal component according to claim 1, characterized in that: In the stress relief annealing of the pretreatment step, the annealing temperature of carbon steel is 550-650°C, and the insulation time is 1-3 hours; the annealing temperature of alloy steel is 600-700°C, and the insulation time is 2-4 hours; the annealing temperature of aluminum alloy is 200-400°C, and the insulation time is 1-2 hours.

4. The surface processing method of a metal component according to claim 1, characterized in that: In the shot peening of the surface refinement treatment step, the particle size of the shot is 0.2-1.5 mm, and the shot is stainless steel shot or ceramic shot.

5. The surface processing method of a metal component according to claim 1, characterized in that: In the electrochemical polishing of the surface refinement step, for parts made of stainless steel, the electrolyte is a mixed electrolyte consisting of phosphoric acid, sulfuric acid and chromic acid.

6. The surface processing method of a metal component according to claim 1, characterized in that: In the ion implantation in the surface modification step, the implanted ions are nitrogen ions and titanium ions.

7. The surface processing method of a metal component according to claim 1, characterized in that: In the laser surface treatment of the surface modification treatment step, the wavelength of the laser beam is 1064nm, 532nm, and the power is 500-50.