A hardware surface treatment process

Abstract

The present application discloses a hardware surface treatment process, which first cleans the hardware surface and forms a 0.01 to 0.05 micron thick pre-plating layer; then the pre-plating layer is subjected to microcrystallization treatment and annealed in a protective atmosphere to release internal stress; then a hard chromium layer is electroplated on the annealed hardware, the current density is controlled not to exceed 200 amperes per square meter to ensure uniform deposition; after electroplating, the hard chromium layer is subjected to polishing treatment, and a nanoscale oxide coating is applied to enhance the bonding force with the substrate; then the surface of the hard chromium layer is treated with ultrasonic vibration of 20 to 50 kHz frequency for 5 minutes to eliminate interface stress; finally, a silicone resin protective film is coated on the surface of the hardware, and is cured at 100 to 150 degrees Celsius for at least 1 hour to provide additional stress buffering effect. The present application effectively controls the internal stress between the substrate and the hard chromium plating layer through the above steps, reduces the occurrence of cracks, at the same time enhances the wear resistance and corrosion resistance of the plating layer, prolongs the service life of the hardware.

Description

Technical Field

[0001] This invention belongs to the field of hardware processing technology, and specifically relates to a hardware surface treatment process. Background Technology

[0002] In modern manufacturing, surface treatment of hardware parts is a crucial process, especially for components requiring high wear resistance and corrosion resistance. Hard chrome plating is a commonly used surface treatment technology due to its excellent physical properties. Hard chrome plating exhibits good hardness, wear resistance, and corrosion resistance, and is widely used in industries such as automotive manufacturing, aerospace, and precision machinery.

[0003] Existing hard chrome plating processes mainly include basic steps such as cleaning the substrate and plating a hard chrome layer. However, in practical applications, it has been found that although hard chrome plating provides good protection, cracks or peeling may still occur under some extreme operating conditions, such as high friction loads or highly corrosive environments. These problems are mainly attributed to the internal stress between the substrate and the plating layer; when this stress exceeds a certain limit, it will lead to plating failure.

[0004] In existing hard chrome plating processes, effectively controlling the stress between the substrate and the plating layer to reduce cracking is one of the key issues that urgently needs to be addressed. Although many methods have been attempted to improve this situation, such as optimizing plating parameters to enhance plating quality, stress-induced defects have not been completely eliminated. Summary of the Invention

[0005] The purpose of this invention is to provide a surface treatment process for hardware parts. By adding a nano-level oxide coating and an organosilicon resin protective film, the adhesion between the coating and the substrate is enhanced, and the wear resistance and corrosion resistance of the hardware parts surface are further improved, thereby solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a surface treatment process for hardware parts, comprising the following steps:

[0007] S1: After cleaning the surface of the hardware parts and removing oil and impurities, a pre-plating layer is formed on the surface of the hardware parts. The thickness of the pre-plating layer is controlled within the range of 0.01 to 0.05 micrometers.

[0008] S2: Microcrystallize the formed pre-plating layer to refine its crystal structure, and perform an intermediate annealing process by heating it to 350 to 450 degrees Celsius under a protective atmosphere and holding it for 30 minutes to release the internal stress of the pre-plating layer.

[0009] S3: Electroplating a hard chrome layer on the annealed hardware parts. During the electroplating process, the current density is controlled to not exceed 200 amperes per square meter to ensure uniform deposition of the hard chrome layer.

[0010] S4: After electroplating, the hard chrome layer is surface polished, and a nano-scale oxide coating is applied to the polished hard chrome layer to enhance the adhesion between the hard chrome layer and the substrate.

[0011] S5: After the oxide coating is completed, the surface of the hard chrome layer is treated with ultrasonic vibration. The frequency is set between 20 kHz and 50 kHz, and the vibration time is 5 minutes to eliminate interface stress.

[0012] S6: Coat the surface of the ultrasonically treated hardware with a layer of silicone resin protective film, set the curing temperature to 100 to 150 degrees Celsius, and the curing time to be no less than 1 hour, to provide additional stress buffering effect.

[0013] Preferably, cleaning the surface of hardware includes the following sub-steps: soaking the hardware in a 1% aqueous solution of nonionic surfactant for 10-15 minutes, then manually brushing the surface of the hardware with a soft brush; rinsing the hardware with running water to remove residual surfactant and loose impurities; after rinsing, placing the hardware in an oven at 60-65 degrees Celsius to dry for 30-35 minutes; and finally wiping the surface of the hardware with a lint-free cloth dampened with isopropyl alcohol to remove fine particles.

[0014] Preferably, forming a pre-plating layer on the surface of the hardware part includes the following sub-steps: immersing the cleaned hardware part in an electrolyte containing nickel salt as the anode, maintaining the electrolyte temperature at 40-45 degrees Celsius, applying a constant current density of 0.5 amperes per square decimeter, and setting the continuous electroplating time to 5-7 minutes; then thoroughly rinsing the hardware part with deionized water to prevent electrolyte residue from affecting subsequent processes; after rinsing, placing the hardware part in a ventilated place to air dry naturally, ready to proceed to the next process.

[0015] Preferably, the microcrystallization treatment of the formed pre-plating layer includes the following sub-steps: placing the pre-plated hardware into a microcrystallization bath containing sodium dodecyl sulfate and urea, maintaining the bath temperature at 30-35 degrees Celsius; applying a pulsed current to the hardware with a frequency of 50 Hz, a current density of 1 ampere per square decimeter, and a treatment time of 2 minutes; immediately removing the hardware from the bath after completion; rinsing the hardware with pure water immediately after removal to remove surface residue; and air-drying the hardware in a dry environment to ensure the surface is completely dry before proceeding to the next step.

[0016] Preferably, the intermediate annealing process includes the following sub-steps: placing the microcrystallized metal parts into a furnace preheated to 350 degrees Celsius, gradually increasing the furnace temperature to 400 degrees Celsius, and ensuring that the furnace is inert gas environment; after reaching the specified temperature, maintaining this temperature for 30 minutes, during which time the inert gas atmosphere remains unchanged; after the heat preservation period, cooling the parts to room temperature with the furnace; after cooling, removing the metal parts from the furnace, ready to proceed to the subsequent processing stage.

[0017] Preferably, electroplating a hard chromium layer on the annealed hardware includes the following sub-steps: preparing an electroplating solution containing chromic acid and adjusting the pH value to between 4.5 and 5.0; immersing the annealed hardware as the cathode in the electroplating solution prepared in the first sub-step; turning on the DC power supply, setting the current density to 180 amperes per square meter, and continuously electroplating for 20-22 minutes; continuously stirring the electroplating solution during electroplating to ensure that the hard chromium layer is uniformly deposited on the surface of the hardware; after electroplating is completed, turning off the power supply, removing the hardware, and thoroughly rinsing it with deionized water.

[0018] Preferably, the surface polishing treatment of the hard chrome layer includes the following sub-steps: applying a polishing paste with a grit of 1000 mesh evenly to the surface of the electroplated hard chrome layer, polishing the hardware with a polishing machine with a rotation speed of 1000 rpm and a wool wheel for 5-7 minutes; after completion, inspecting the surface of the hard chrome layer to confirm that the micro-roughness has been improved; then, thoroughly cleaning the surface of the hardware with a high-pressure water gun to remove all polishing paste residue, and after cleaning, wiping the hardware dry with a clean, lint-free cloth to ensure that the surface is free of water stains and other contaminants.

[0019] Preferably, applying a nanoscale oxide coating to the polished hard chrome layer includes the following sub-steps: placing the polished hardware in a vacuum coating chamber, drawing a vacuum, and introducing aluminum metal vapor into the coating chamber; depositing a thin film of aluminum oxide with a thickness of about 50 nanometers on the surface of the hard chrome layer by electron beam evaporation; after the deposition process is completed, gradually restoring the coating chamber to normal pressure; removing the hardware and checking whether the coating uniformly covers the surface of the hard chrome layer to confirm that it is well bonded to the substrate.

[0020] Preferably, the ultrasonic vibration treatment of the hard chrome layer surface includes the following sub-steps: placing the hardware part after applying a layer of nano-scale oxide coating on an ultrasonic vibration table, starting the ultrasonic device, and adjusting the frequency to 30 kHz; after setting the frequency, starting the vibration treatment, setting the duration to 5 minutes, monitoring the working status of the vibration table during the vibration treatment to ensure that the frequency is stable and the hardware part remains stationary; after the treatment is completed, turning off the ultrasonic device, removing the hardware part, and checking whether there are signs of stress release on the surface.

[0021] Preferably, coating the surface of the ultrasonically treated hardware with a layer of silicone resin protective film includes the following sub-steps: uniformly spraying a layer of silicone resin solution onto the surface of the ultrasonically treated hardware; after spraying, letting the hardware stand for 10-15 minutes to allow the silicone resin to initially solidify; during the standing period, preparing an oven and preheating it to 120 degrees Celsius; placing the settled hardware into the preheated oven to begin the curing process, with a curing time of not less than 1 hour to allow the silicone resin to fully cure.

[0022] Technical effects and advantages of the present invention: The surface treatment process for hardware parts proposed in this invention has the following advantages compared with the prior art:

[0023] This invention effectively controls the internal stress between the substrate and the hard chrome plating by microcrystallizing the pre-plating layer and annealing it under a protective atmosphere, thereby reducing crack formation. Furthermore, by adding a nano-scale oxide coating and an organosilicon resin protective film, not only is the adhesion between the plating layer and the substrate enhanced, but the wear resistance and corrosion resistance of the hardware surface are also further improved, thus extending the service life of the hardware. Attached Figure Description

[0024] Figure 1 This is a flowchart of a surface treatment process for hardware parts according to the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This invention provides a surface treatment process for hardware parts, such as... Figure 1 As shown, it includes the following steps:

[0027] S1: After cleaning the surface of the hardware parts and removing oil and impurities, a pre-plating layer is formed on the surface of the hardware parts. The thickness of the pre-plating layer is controlled within the range of 0.01 to 0.05 micrometers.

[0028] Further cleaning of the hardware surface includes the following sub-steps:

[0029] Immersion treatment: Prepare a 1% aqueous solution using a nonionic surfactant, and completely immerse the hardware parts in the solution for 10 to 15 minutes to ensure that the oil and impurities are fully dissolved.

[0030] Hand washing: After soaking, use a soft brush to hand wash the surface of the hardware, especially the grooves and hard-to-reach areas, and clean them carefully to ensure that there is no residual dirt on the surface.

[0031] Rinse with running water: After brushing, rinse the hardware thoroughly with running water to remove any residual surfactants and loose impurities on the surface, ensuring that the surface is clean and free of residue.

[0032] Drying process: After rinsing, place the hardware parts in an oven at a temperature of 60 to 65 degrees Celsius and set the drying time to 30 to 35 minutes to ensure that the surface of the hardware parts is completely dry.

[0033] Isopropyl alcohol wiping: After drying, use a lint-free cloth dampened with an appropriate amount of isopropyl alcohol to carefully wipe the surface of the hardware parts to remove any small particles and prepare for subsequent processes.

[0034] Furthermore, forming a pre-plating layer on the surface of the hardware includes the following sub-steps:

[0035] Immersion in electrolyte: The cleaned hardware parts, after the above steps, are immersed in an electrolyte containing nickel salt as the anode. The electrolyte temperature is maintained at 40 to 45 degrees Celsius to maintain the stability of the electrolyte and the activity of the metal ions.

[0036] Apply current: Apply a constant current density of 0.5 amperes per square decimeter to the hardware parts immersed in the electrolyte, and set the continuous electroplating time to 5 to 7 minutes to ensure uniform deposition of the pre-plating layer and control the thickness within the range of 0.01 to 0.05 micrometers.

[0037] Rinsing to remove residue: After electroplating, immediately rinse the hardware parts thoroughly with deionized water to avoid electrolyte residue from adversely affecting subsequent processes.

[0038] Air dry: After rinsing, place the hardware in a well-ventilated place to air dry naturally, in preparation for the next process.

[0039] Through the above steps, the surface treatment process for hardware parts provided by the present invention can effectively remove oil and impurities from the surface of hardware parts and form a uniform and thin pre-plating layer on its surface. This pre-plating layer not only helps the hard chrome plating layer in the subsequent process to adhere better, but also significantly reduces the internal stress between the hard chrome layer and the substrate through fine cleaning and pre-plating treatment, thereby effectively preventing the occurrence of cracks and peeling.

[0040] Furthermore, by controlling the thickness and uniformity of the pre-plating layer, this invention enhances the adhesion between the hard chrome layer and the substrate, further improving the wear resistance and corrosion resistance of the hardware surface and extending the service life of the hardware.

[0041] S2: Microcrystallize the formed pre-plating layer to refine its crystal structure, and perform an intermediate annealing process by heating it to 350 to 450 degrees Celsius under a protective atmosphere and holding it for 30 minutes to release the internal stress of the pre-plating layer.

[0042] Further microcrystallization treatment of the formed pre-coating layer includes the following sub-steps:

[0043] Immersion in a microcrystallization bath: The hardware parts that have undergone the first step and formed a pre-plating layer are placed in a microcrystallization bath containing sodium dodecyl sulfate and urea. The bath temperature is maintained at 30 to 35 degrees Celsius to promote the refinement of the crystal structure of the pre-plating layer.

[0044] Apply pulsed current: Based on the first sub-step, apply a pulsed current with a frequency of 50 Hz and a current density of 1 ampere per square decimeter to the hardware for 2 minutes to refine the crystal structure of the pre-plated layer.

[0045] Remove the hardware: After completing the second sub-step, immediately remove the hardware from the bath to avoid prolonged contact with the bath liquid and overtreatment.

[0046] Rinse the hardware: After removing it, immediately rinse the hardware with purified water to remove any residual bath liquid from the surface.

[0047] Air dry: After rinsing, place the hardware in a dry environment to air dry naturally, ensuring the surface is completely dry before proceeding to the next step.

[0048] The intermediate annealing process further includes the following sub-steps:

[0049] Place in the furnace: Place the metal parts that have undergone microcrystallization into the furnace preheated to 350 degrees Celsius.

[0050] Heating process: Gradually increase the furnace temperature to 400 degrees Celsius and ensure that the furnace is inert gas environment to prevent oxidation reaction.

[0051] Heat preservation treatment: After the furnace temperature reaches 400 degrees Celsius, maintain this temperature for 30 minutes, and keep the inert gas atmosphere unchanged during this period to release the stress in the pre-plating layer.

[0052] Cooling with the furnace: After the heat preservation period, the furnace is cooled to room temperature to avoid rapid cooling that could lead to new stress.

[0053] Through the above steps, the surface treatment process for hardware parts provided by this invention can effectively refine the crystal structure of the pre-plating layer, enhancing the density and uniformity of the plating layer. Microcrystallization treatment makes the crystals in the pre-plating layer smaller, improving the overall performance of the plating layer. The subsequent intermediate annealing process, by heating and holding in a protective atmosphere, effectively releases residual stress within the pre-plating layer, reducing cracks and peeling caused by excessive stress.

[0054] The entire process not only improves the adhesion between the hard chrome plating and the substrate, but also significantly enhances the wear resistance and corrosion resistance of the hardware surface, thereby extending the service life of the hardware.

[0055] S3: Electroplating a hard chrome layer onto the annealed hardware parts, controlling the current density during electroplating to not exceed 200 amperes per square meter to ensure uniform deposition of the hard chrome layer; further including the following sub-steps:

[0056] Prepare the electroplating solution: Prepare an electroplating solution containing chromic acid and adjust the pH value to between 4.5 and 5.0 to ensure that the solution is in the optimal electroplating state.

[0057] Immersion of hardware parts: Use the annealed hardware parts as cathodes and immerse them in the prepared electroplating solution to ensure that the hardware parts are completely submerged in the solution.

[0058] Power on electroplating: Turn on the DC power supply, set the current density to 180 amps per square meter, and continue electroplating for 20 to 22 minutes to ensure that the hard chrome layer can be deposited evenly on the surface of the hardware.

[0059] Stirring the solution: Throughout the electroplating process, the electroplating solution is continuously stirred to ensure that the chromic acid in the solution is evenly distributed, avoiding local concentrations that are too high or too low, thereby ensuring the uniformity of the hard chromium layer on the surface of the hardware.

[0060] Remove the hardware: After electroplating is completed, turn off the power and immediately remove the hardware from the electroplating solution. Then, immediately rinse the surface of the hardware thoroughly with deionized water to remove all residual electroplating solution and prevent corrosion or other adverse reactions in subsequent processes.

[0061] Air dry: After rinsing, place the hardware in a well-ventilated environment to air dry naturally, in preparation for the next process.

[0062] Through the above steps, the surface treatment process for hardware parts provided by this invention forms a uniform and dense hard chrome layer on the surface of the hardware parts after annealing. By strictly controlling the current density during the electroplating process to not exceed 200 amperes per square meter and maintaining it at 180 amperes per square meter, uniform deposition of the hard chrome layer on the surface of the hardware parts is ensured, avoiding performance inconsistencies caused by localized excessive thickness or thinness.

[0063] Furthermore, the continuous stirring of the electroplating solution further ensures the uniformity of the hard chrome layer and enhances the adhesion between the plating layer and the substrate. This treatment results in a hard chrome layer that not only possesses excellent wear resistance and corrosion resistance but also effectively resists the effects of the external environment, significantly extending the service life of the hardware components. Simultaneously, the uniform hard chrome layer reduces cracking and peeling caused by stress concentration, improving the overall quality and reliability of the hardware components.

[0064] S4: After electroplating, the hard chrome layer is surface polished, and a nano-scale oxide coating is applied to the polished hard chrome layer to enhance the adhesion between the hard chrome layer and the substrate.

[0065] Further surface polishing of the hard chrome layer includes the following sub-steps:

[0066] Apply polishing paste: Use polishing paste with a grit of 1000 mesh and apply it evenly to the surface of the electroplated hard chrome layer to ensure uniform coverage of the entire surface.

[0067] Polishing: The hardware is polished using a polishing machine with a rotation speed of 1000 rpm and equipped with a wool wheel for 5 to 7 minutes to ensure that the micro-roughness of the hard chrome layer surface is effectively improved.

[0068] Surface inspection: After polishing, inspect the surface of the hard chrome layer to confirm that the micro-roughness has been improved and the surface is smooth and free of scratches.

[0069] Cleaning hardware: Use a high-pressure water gun to thoroughly clean the surface of the hardware to remove all polishing paste residue and ensure that the surface is clean and free of contamination.

[0070] Dry the hardware: After cleaning, wipe the hardware dry with a clean, lint-free cloth to ensure that there are no water stains or other contaminants on the surface, in preparation for the next step.

[0071] Further applying a nanoscale oxide coating to the polished hard chromium layer includes the following sub-steps:

[0072] Prepare the coating chamber: Place the polished hardware parts in the vacuum coating chamber and evacuate to the required pressure level.

[0073] Aluminum metal vapor is introduced into the coating chamber in preparation for oxide coating deposition.

[0074] Deposited oxide coating: A thin film of aluminum oxide (Al2O3) with a thickness of about 50 nanometers is deposited on the surface of the hard chromium layer by electron beam evaporation to ensure that the coating uniformly covers the surface of the hard chromium layer.

[0075] Restoring atmospheric pressure: After the deposition process is completed, the coating chamber is gradually restored to atmospheric pressure to avoid sudden pressure changes affecting the coating.

[0076] Inspect the coating: Remove the hardware and check whether the coating evenly covers the surface of the hard chrome layer, confirm that it is well bonded to the substrate, and that there are no obvious defects or unevenness.

[0077] Through the above steps, the surface treatment process for hardware parts provided by this invention can effectively improve the micro-roughness of the hard chrome layer surface, making its surface smoother and improving the appearance quality and tactile feel of the hardware parts. Polishing not only removes micro-unevenness on the surface but also provides a better adhesion base for subsequent oxide coatings.

[0078] Applying a nano-scale oxide coating further enhances the adhesion between the hard chrome layer and the substrate, improving the coating's wear resistance and corrosion resistance. The Al2O3 coating possesses excellent chemical stability and mechanical strength, effectively resisting environmental erosion while reducing stress between the hard chrome layer and the substrate, thus lowering the risk of cracking and peeling.

[0079] Overall, this process not only improves the aesthetics and functionality of hardware surfaces, but also significantly extends the service life of hardware, making it suitable for a variety of demanding applications.

[0080] S5: After the oxide coating is completed, the surface of the hard chromium layer is treated with ultrasonic vibration at a frequency between 20 kHz and 50 kHz for 5 minutes to eliminate interfacial stress; further steps include the following sub-steps:

[0081] Place the hardware components: Place the hardware components, which have been treated with nano-oxide coating, stably on the ultrasonic vibration table to ensure that the hardware components are stable and do not move.

[0082] Start the ultrasonic device: Start the ultrasonic device and adjust the frequency to 30 kHz. This is the optimal frequency range selected based on experimental data, which can effectively transfer energy to the surface of the hard chrome layer.

[0083] Initiate vibration treatment: After setting the frequency, initiate vibration treatment for a duration of 5 minutes. During this period, closely monitor the vibration table to ensure frequency stability and that the hardware remains stationary throughout the treatment process to prevent positional shifts due to vibration.

[0084] Check the treatment effect: After the vibration treatment is completed, turn off the ultrasonic device and carefully remove the hardware. Check the surface of the hard chrome layer for signs of stress release, such as reduced or disappeared cracks, and a smoother surface.

[0085] Record the results: Record the inspection results to ensure that the vibration treatment achieved the expected effect, that is, effectively eliminating the stress at the interface between the hard chrome layer and the substrate.

[0086] Through the above steps, the surface treatment process for hardware parts provided by this invention utilizes ultrasonic vibration treatment to effectively eliminate the stress at the interface between the hard chrome layer and the substrate. Ultrasonic vibration treatment transmits energy to the surface of the hard chrome layer through high-frequency vibration, thereby alleviating microscopic defects within the hard chrome layer, reducing interface stress, and decreasing the risk of cracking and peeling.

[0087] Specifically, the ultrasonic vibration treatment frequency was set at 30 kHz for 5 minutes. This parameter setting ensures that energy is evenly transferred to the surface of the hard chrome layer, promoting uniform stress release. Simultaneously, the operating status of the vibration table was monitored during the vibration treatment process to guarantee consistency and effectiveness, avoiding poor treatment results due to equipment malfunction or improper operation.

[0088] After ultrasonic vibration treatment, the adhesion between the hard chrome layer and the substrate is significantly enhanced, and the surface quality is improved. This not only improves the wear resistance and corrosion resistance of the hardware but also further extends its service life.

[0089] S6: Apply a layer of silicone resin protective film to the surface of the ultrasonically treated hardware parts. Set the curing temperature to 100 to 150 degrees Celsius and the curing time to no less than 1 hour to provide additional stress buffering. Further steps include the following:

[0090] Spraying silicone resin solution: Evenly spray a layer of silicone resin solution onto the surface of the hardware parts after ultrasonic treatment. Ensure uniform spraying, covering the entire surface of the hard chrome layer, and avoid any missed spots or uneven spraying.

[0091] Initial setting: After spraying, let the hardware stand for 10 to 15 minutes to allow the silicone resin to initially solidify. During this period, the silicone resin will begin to cure and form a stable film.

[0092] Prepare the oven: During the resting period, prepare the oven and preheat it to 120 degrees Celsius. Ensure the oven temperature is evenly distributed to guarantee consistent curing results.

[0093] Curing process: Place the settled hardware parts into an oven preheated to 120 degrees Celsius to begin the curing process. The curing time should be no less than 1 hour to ensure that the silicone resin is fully cured and forms a strong and uniform protective film.

[0094] Remove the hardware: After curing, turn off the oven power and wait for the oven temperature to drop to a safe level before carefully removing the hardware. Check whether the silicone resin protective film is evenly covering the surface of the hard chrome layer, and confirm that it is tightly bonded to the hard chrome layer without blistering or peeling.

[0095] Final inspection: A comprehensive inspection is carried out on the cured hardware to ensure that the surface is flat and free of defects, that there is no obvious boundary between the silicone resin protective film and the hard chrome layer, and that the overall bonding is good.

[0096] Through the above steps, the surface treatment process for hardware parts provided by this invention coats a layer of silicone resin protective film onto the surface of the hard chrome layer after ultrasonic treatment, and ensures the full curing of the protective film through high-temperature curing. This process not only further enhances the bonding force between the hard chrome layer and the substrate, but also provides an additional stress buffering effect, significantly improving the wear resistance and corrosion resistance of the hardware parts surface.

[0097] Specifically, the silicone resin protective film exhibits excellent weather resistance and chemical stability, effectively resisting the erosion of the external environment. The cured silicone resin protective film forms a uniform and dense film covering the surface of the hard chrome layer, not only enhancing surface smoothness but also reducing stress concentration between the hard chrome layer and the substrate, thus lowering the risk of cracking and peeling.

[0098] Furthermore, curing at 120 degrees Celsius for at least one hour ensures full cross-linking and curing of the silicone resin, forming a stable and durable protective layer. This not only improves the surface quality of the hardware but also significantly extends its service life, enabling it to perform excellently in various complex working environments and making it suitable for industrial applications with high surface performance requirements.

[0099] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A surface treatment process for hardware parts, characterized in that, Includes the following steps: S1: After cleaning the surface of the hardware parts and removing oil and impurities, a pre-plating layer is formed on the surface of the hardware parts. The thickness of the pre-plating layer is controlled within the range of 0.01 to 0.05 micrometers. The pre-plating layer formation on the surface of the hardware parts includes the following sub-steps: Immersing the cleaned hardware parts in an electrolyte containing nickel salt as the cathode, maintaining the electrolyte temperature at 40-45 degrees Celsius, applying a constant current density of 0.5 amperes per square decimeter, and setting the electroplating time to 5-7 minutes, then thoroughly rinsing the hardware parts with deionized water to prevent electrolyte residue from affecting subsequent processes. After rinsing, the hardware parts are placed in a ventilated place to air dry naturally, ready to proceed to the next process. S2: The formed pre-plating layer is subjected to microcrystallization treatment to refine the crystal structure of the pre-plating layer. An intermediate annealing process is then carried out, heating to 350 to 450 degrees Celsius under a protective atmosphere and holding for 30 minutes to release the internal stress of the pre-plating layer. The microcrystallization treatment of the formed pre-plating layer includes the following sub-steps: the formed pre-plating layer hardware is placed in a microcrystallization bath containing sodium dodecyl sulfate and urea. The bath temperature is maintained at 30-35 degrees Celsius. A pulsed current is applied to the hardware with a frequency of 50 Hz and a current density of 1 ampere per square decimeter. The treatment time is 2 minutes. After completion, the hardware is immediately removed from the bath. After removal, the hardware is immediately rinsed with pure water to remove surface residues. The hardware is then placed in a dry environment to air dry, ensuring that the surface is completely dry before proceeding to the next step. S3: Electroplating a hard chrome layer on the annealed hardware parts. During the electroplating process, the current density is controlled to not exceed 200 amperes per square meter to ensure uniform deposition of the hard chrome layer. S4: After electroplating, the hard chrome layer is surface polished, and a nano-scale oxide coating is applied to the polished hard chrome layer to enhance the adhesion between the hard chrome layer and the substrate. The application of a nano-scale oxide coating to the polished hard chrome layer includes the following sub-steps: the polished hardware is placed in a vacuum coating chamber, a vacuum is drawn, and aluminum metal vapor is introduced into the coating chamber. A 50-nanometer-thick aluminum oxide film is deposited on the surface of the hard chrome layer by electron beam evaporation. After the deposition process is completed, the coating chamber is gradually restored to normal pressure. The hardware is removed, and the coating is checked to see if it uniformly covers the surface of the hard chrome layer and to confirm that it is well bonded to the substrate. S5: After the oxide coating is completed, the surface of the hard chrome layer is treated with ultrasonic vibration. The frequency is set between 20 kHz and 50 kHz, and the vibration time is 5 minutes to eliminate interface stress. S6: Coat the surface of the ultrasonically treated hardware with a layer of silicone resin protective film, set the curing temperature to 100 to 150 degrees Celsius, and the curing time to be no less than 1 hour, to provide additional stress buffering effect.

2. The surface treatment process for hardware parts according to claim 1, characterized in that, Cleaning the surface of hardware components includes the following sub-steps: Use a 1% aqueous solution of nonionic surfactant to soak the hardware parts for 10-15 minutes, and then manually scrub the surface of the hardware parts with a soft brush. Rinse the hardware parts with running water to remove residual surfactants and loose impurities from the surface. After rinsing, place the hardware parts in an oven at 60-65 degrees Celsius to dry for 30-35 minutes. Use a lint-free cloth dampened with isopropyl alcohol to wipe the surface of the hardware parts to remove fine particles.

3. The surface treatment process for hardware parts according to claim 1, characterized in that, The intermediate annealing process includes the following sub-steps: The metal parts that have undergone microcrystallization are placed in a furnace preheated to 350 degrees Celsius, and the furnace temperature is gradually increased to 400 degrees Celsius, while ensuring that the furnace is inert gas environment. Once the specified temperature is reached, maintain this temperature for 30 minutes, keeping the inert gas atmosphere constant during this period. After the holding period, cool the parts to room temperature with the furnace. Once cooling is complete, remove the hardware from the furnace chamber and prepare for subsequent processing.

4. The surface treatment process for hardware parts according to claim 3, characterized in that, The process of electroplating a hard chrome layer onto annealed hardware includes the following sub-steps: Prepare an electroplating solution containing chromic acid and adjust the pH value to between 4.5 and 5.0; The annealed hardware parts are used as cathodes and immersed in an electroplating solution containing chromic acid. Turn on the DC power supply, set the current density to 180 amperes per square meter, and continue electroplating for 20-22 minutes. During electroplating, the electroplating solution is continuously stirred to ensure that the hard chromium layer is uniformly deposited on the surface of the hardware. After electroplating is completed, the power is turned off, the hardware is removed, and it is thoroughly rinsed with deionized water.

5. The surface treatment process for hardware parts according to claim 4, characterized in that, The surface polishing process for the hard chrome layer includes the following sub-steps: Apply 1000-mesh polishing paste evenly to the surface of the electroplated hard chrome layer, and polish the hardware with a polishing machine with a rotation speed of 1000 rpm and a wool wheel for 5-7 minutes. After completion, inspect the surface of the hard chrome layer to confirm that the micro-roughness has been improved; Then, use a high-pressure water gun to thoroughly clean the surface of the hardware to remove all polishing paste residue. After cleaning, wipe the hardware dry with a clean, lint-free cloth to ensure that there are no water stains or other contaminants on the surface.

6. The surface treatment process for hardware parts according to claim 1, characterized in that, The ultrasonic vibration treatment of the hard chrome layer surface includes the following sub-steps: After applying a layer of nano-scale oxide coating, place the hardware part on an ultrasonic vibration table, start the ultrasonic device, and adjust the frequency to 30 kHz. After setting the frequency, start the vibration treatment and set the duration to 5 minutes. During the vibration treatment, monitor the working status of the vibration table to ensure that the frequency is stable and the hardware remains stationary. After completion, turn off the ultrasonic device, remove the hardware, and check the surface for signs of stress release.

7. The surface treatment process for hardware parts according to claim 6, characterized in that, Applying a protective film of silicone resin to the surface of the ultrasonically treated hardware includes the following sub-steps: A layer of silicone resin solution is evenly sprayed onto the surface of the ultrasonically treated hardware. After spraying, let the hardware stand for 10-15 minutes to allow the silicone resin to initially solidify. During this time, prepare an oven and preheat it to 120 degrees Celsius. Place the settled hardware parts into a preheated oven and begin the curing process. The curing time should be no less than 1 hour to allow the silicone resin to fully cure.

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