A vacuum electroplating PVD coating process

Abstract

The invention discloses a vacuum electroplating PVD coating process, and the technical scheme thereof mainly comprises the following steps: S1, wheel hub degreasing pretreatment; S2, pickling; S3, passivation; S4, base powder coating; S5, grinding; S6, cleaning and drying; S7, medium powder coating; S8, coating; S9, painting; before coating the wheel hub, the process pretreats the wheel hub more fully, and the means adopted are different from the traditional means, and the stability of subsequent coating can be increased by degreasing pretreatment, pickling and passivation of the wheel hub, and the configured degreasing agent is different from the traditional degreasing agent; and through the process, it is found in practice that the scrap rate of the coating is reduced, the coating is difficult to fall off, and the service life of the coating is improved.

Description

Technical Field

[0001] The invention relates to the field of wheel hub coating, and in particular to a vacuum electroplating PVD coating process. Background Art

[0002] Common car wheels include steel wheels and aluminum alloy wheels. Steel wheels are high in strength and are often used in large trucks; however, steel wheels are heavy and have a single appearance, which does not conform to today's low-carbon and fashionable concepts, and are gradually being replaced by aluminum alloy wheels. Coating the wheels is an effective means to increase the life of the wheels and is widely used.

[0003] The existing Chinese patent with publication number CN110105815A discloses a coating agent and coating process for automobile aluminum alloy wheel hubs. The specific process flow is as follows: processing; finishing to remove black skin, bruises, and aluminum sticking on the wheel hub surface, and smoothing the uneven parts with sandpaper to make the surface smooth; cleaning: first cleaning, removing impurities, and degreasing in hot water, and finally cleaning with pure water; drying: after cleaning with clean water, the water marks left on the wheel surface are blown dry, and then high-temperature baking is performed to remove surface impurities; pretreatment: conversion film treatment is performed using an alkaline chromate method; spraying primer: spraying epoxy polyester powder coating using an electrostatic spraying method, and then curing the coating through a baking oven at 160°C for 15 minutes; grinding: grinding the surface of the wheel hub after spraying the primer with 400 sandpaper; painting

[0004] The above-mentioned coating agent and coating process for automobile aluminum alloy wheel hub solve the problem of low mechanical strength of coating on the wheel hub surface. However, the above-mentioned coating agent and coating process for automobile aluminum alloy wheel hub still have some disadvantages, such as: first, the pretreatment of the wheel hub is insufficient before coating, and the means used are very simple; second, the primer coating is not coated, and the subsequent coating and painting are easy to fall off, resulting in a short service life; third, the coating process parameters used are often accompanied by a high defective rate. Summary of the invention

[0005] In view of the problems mentioned in the background technology, the purpose of the present invention is to provide a vacuum electroplating PVD coating process to solve the problems mentioned in the background technology.

[0006] The above technical objectives of the present invention are achieved through the following technical solutions:

[0007] A vacuum electroplating PVD coating process specifically comprises the following steps:

[0008] S1. Wheel hub degreasing pretreatment: select the following weight components: 30-40 parts of 10% potassium silicate solution, 20-30 parts of tolyltriazole, 20-30 parts of pyrrolidone, 30-40 parts of 10% disodium hydrogen phosphate solution and 10-15 parts of 15% sodium carbonate solution, and mix them to make a degreasing agent, then place the aluminum alloy wheel hub in the degreasing agent for degreasing, control the degreasing temperature to 40-45°C, and the degreasing time to 15-20min;

[0009] S2, pickling: immersing the aluminum alloy wheel hub obtained in S1 in phosphoric acid for pickling for 5-10 minutes;

[0010] S3, passivation: the aluminum alloy wheel hub obtained in S2 is placed in a chromium-free passivation solution composed of epoxysilane and fluorozirconic acid in a mass ratio of 1:1 for passivation;

[0011] S4, coating with primer powder: placing the substrate in S3 in a vacuum coating chamber and coating the primer powder on its surface by multi-target continuous magnetron sputtering, controlling the vacuum degree in the vacuum coating chamber to 0.004-0.0045 Pa and the temperature to 30-35° C.;

[0012] S5. Grinding: Place abrasives in the vibration grinder, so that the vibration grinder drives the abrasives to move relative to the wheel hub for rough grinding, and then use 120# sandpaper to grind the surface of the wheel hub until the surface roughness of the wheel hub is Ra 0.05;

[0013] S6, cleaning and drying: cleaning the wheel hub obtained in S5 with high-pressure water, wherein the high-pressure water used is deionized water, and drying the surface after cleaning;

[0014] S7, coating with dielectric powder: spraying a layer of translucent dielectric powder coating on the surface of the wheel hub obtained in S6 by electrostatic spraying;

[0015] S8, coating: placing the wheel hub obtained in S7 in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 60-70V, the current is 50-60A, the coating time is 220-250S, the temperature in the vacuum coating chamber is controlled to be 60-80°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 200-240mm, the deposition thickness on the wheel hub surface is controlled to be 1-2um, and the air pressure in the vacuum coating chamber is controlled to be 0.1-2Pa;

[0016] S9, spray painting: spray a finishing varnish on the surface of the hub obtained in S8, wherein the finishing varnish is selected from one of amino varnish, acrylic varnish, and polyurethane varnish, and dry after spraying, and control the drying temperature to be 120-125° C. and the drying time to be 20-25 min.

[0017] Preferably, the primer coating in S4 is a mixture of epoxy resin, hydroxyalkylamide and polyetheretherketone resin in a mass ratio of 5:1:1.

[0018] Preferably, the medium powder in S7 includes 100-120 parts of phenolic epoxy resin, 20-30 parts of curing agent, 2-4 parts of leveling agent, and 1-3 parts of accelerator.

[0019] Preferably, the curing agent is selected from polyetheramine curing agents and polyamide curing agents.

[0020] Preferably, the leveling agent is one of isophorone, diacetone alcohol and Solvesso 150.

[0021] Preferably, the accelerator is one of accelerator TBTD, accelerator NOBS, accelerator TETD and accelerator DCBS.

[0022] Preferably, the abrasive in S5 is a mixture of one or more of brown corundum abrasive, black silicon carbide abrasive, green silicon carbide abrasive, cubic silicon carbide abrasive, and cerium silicon carbide abrasive.

[0023] Preferably, during the S8 coating, the wheel hub obtained in the S7 is placed in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 63-66V, the current is 54-58A, the coating time is 230-240S, the temperature in the vacuum coating chamber is controlled to be 63-70°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 230-240mm, the deposition thickness on the surface of the wheel hub is controlled to be 1-2um, and the air pressure in the vacuum coating chamber is controlled to be 0.1-2Pa.

[0024] Preferably, the plating material in S8 is an alloy plating material including aluminum, nickel and chromium, and argon gas is injected for protection during the plating process.

[0025] In summary, the present invention mainly has the following beneficial effects:

[0026] First, this process pre-treats the wheel hub fully before coating it, and the means used are different from traditional means. The stability of subsequent coating can be increased by pre-treating the wheel hub with degreasing, pickling and passivation, and the degreasing agent used is different from the traditional degreasing agent.

[0027] Second, this process uses a primer coating process on the surface of the wheel hub after passivation. It uses a multi-target continuous magnetron sputtering method, and then adds a grinding process and a cleaning and drying process. It also uses a dielectric powder coating and a coating process. Compared with the traditional process, it is found in practice that the scrap rate of the coating is reduced;

[0028] Third, this process adopts multi-target continuous magnetron sputtering, and then adds grinding process and cleaning and drying process, and then adopts dielectric powder coating and coating process, so that the coating is difficult to fall off and the life of the coating is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a process flow chart for the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Example 1

[0032] refer to Figure 1 , a vacuum electroplating PVD coating process, specifically comprising the following steps:

[0033] The specific steps include:

[0034] S1. Wheel hub degreasing pretreatment: Select the following weight components: 30 parts of 10% potassium silicate solution, 20 parts of tolyltriazole, 20 parts of pyrrolidone, 30 parts of 10% disodium hydrogen phosphate solution and 10 parts of 15% sodium carbonate solution, and mix them to make a degreasing agent, then place the aluminum alloy wheel hub in the degreasing agent for degreasing, control the degreasing temperature to 40°C, and the degreasing time to 15 minutes;

[0035] S2, pickling: immerse the aluminum alloy wheel hub obtained in S1 in phosphoric acid for pickling for 5 minutes;

[0036] S3, passivation: the aluminum alloy wheel hub obtained in S2 is placed in a chromium-free passivation solution composed of epoxysilane and fluorozirconic acid in a mass ratio of 1:1 for passivation;

[0037] S4, coating with primer powder: placing the substrate in S3 in a vacuum coating chamber and coating the primer powder on its surface by multi-target continuous magnetron sputtering, controlling the vacuum degree in the vacuum coating chamber to 0.004 Pa and the temperature to 30°C;

[0038] S5. Grinding: Place abrasives in the vibration grinder, so that the vibration grinder drives the abrasives to move relative to the wheel hub for rough grinding, and then use 120# sandpaper to grind the surface of the wheel hub until the surface roughness of the wheel hub is Ra 0.05;

[0039] S6, cleaning and drying: cleaning the wheel hub obtained in S5 with high-pressure water, wherein the high-pressure water used is deionized water, and drying the surface after cleaning;

[0040] S7, dielectric powder coating: spray a layer of translucent dielectric powder coating on the surface of the wheel hub obtained in S6 by electrostatic spraying;

[0041] S8, coating: placing the wheel hub obtained in S7 in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 60V, the current is 50A, the coating time is 220S, the temperature in the vacuum coating chamber is controlled to be 60°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 200mm, the deposition thickness on the wheel hub surface is controlled to be 1um, and the air pressure in the vacuum coating chamber is controlled to be 0.1Pa;

[0042] S9, spray painting: spray the surface of the hub obtained in S8 with a finishing varnish, wherein the finishing varnish is selected from one of amino varnish, acrylic varnish, and polyurethane varnish, and dry it after spraying, and control the drying temperature to be 120° C. and the drying time to be 20 min.

[0043] Among them, the primer coating in S4 is a mixture of epoxy resin, hydroxyalkylamide and polyetheretherketone resin in a mass ratio of 5:1:1.

[0044] The medium powder in S7 includes 100 parts of phenolic epoxy resin, 20 parts of curing agent, 2 parts of leveling agent and 1 part of accelerator.

[0045] Wherein, the curing agent is selected from polyether amine curing agents.

[0046] Among them, the leveling agent is isophorone.

[0047] Wherein, the accelerator is accelerator TBTD.

[0048] The abrasive in S5 is a mixture of brown corundum abrasive and black silicon carbide abrasive.

[0049] Among them, the coating material in S8 is an alloy coating material, including aluminum, nickel and chromium, and argon gas is injected for protection during coating.

[0050] Among them, before the wheel hub is coated, the pretreatment of the wheel hub in this process is relatively sufficient, and the means adopted are different from the traditional means. The stability of the subsequent coating can be increased by degreasing pretreatment, pickling and passivation of the wheel hub, and the configured degreasing agent is different from the traditional degreasing agent; and after the wheel hub is passivated, the present process adopts a primer powder coating process on its surface, which adopts a multi-target continuous magnetron sputtering method, and then adds a grinding process and a cleaning and drying process, and then adopts a dielectric powder coating and a coating process. Compared with the traditional process, it is found in practice that the scrap rate of the coating is reduced; and the present process adopts a multi-target continuous magnetron sputtering method, and then adds a grinding process and a cleaning and drying process, and then adopts a dielectric powder coating and a coating process, which makes the coating difficult to fall off and improves the life of the coating.

[0051] Example 2

[0052] refer to Figure 1 , a vacuum electroplating PVD coating process, specifically comprising the following steps:

[0053] The specific steps include:

[0054] S1. Wheel hub degreasing pretreatment: Select the following weight components: 35 parts of 10% potassium silicate solution, 25 parts of tolyltriazole, 25 parts of pyrrolidone, 32 parts of 10% disodium hydrogen phosphate solution and 12 parts of 15% sodium carbonate solution, and mix them to make a degreasing agent, then place the aluminum alloy wheel hub in the degreasing agent for degreasing, control the degreasing temperature to 41°C, and the degreasing time to 16 minutes;

[0055] S2, pickling: immerse the aluminum alloy wheel hub obtained in S1 in phosphoric acid for pickling for 5 minutes;

[0056] S3, passivation: the aluminum alloy wheel hub obtained in S2 is placed in a chromium-free passivation solution composed of epoxysilane and fluorozirconic acid in a mass ratio of 1:1 for passivation;

[0057] S4, coating with primer powder: placing the substrate in S3 in a vacuum coating chamber and coating the primer powder on its surface by multi-target continuous magnetron sputtering, controlling the vacuum degree in the vacuum coating chamber to 0.0042 Pa and the temperature to 32°C;

[0058] S5. Grinding: Place abrasives in the vibration grinder, so that the vibration grinder drives the abrasives to move relative to the wheel hub for rough grinding, and then use 120# sandpaper to grind the surface of the wheel hub until the surface roughness of the wheel hub is Ra 0.05;

[0059] S6, cleaning and drying: cleaning the wheel hub obtained in S5 with high-pressure water, wherein the high-pressure water used is deionized water, and drying the surface after cleaning;

[0060] S7, dielectric powder coating: spray a layer of translucent dielectric powder coating on the surface of the wheel hub obtained in S6 by electrostatic spraying;

[0061] S8, coating: placing the wheel hub obtained in S7 in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 64V, the current is 55A, the coating time is 230S, the temperature in the vacuum coating chamber is controlled to be 60°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 200mm, the deposition thickness on the wheel hub surface is controlled to be 1um, and the air pressure in the vacuum coating chamber is controlled to be 0.1Pa;

[0062] S9, spray painting: spray the surface of the hub obtained in S8 with a finishing varnish, wherein the finishing varnish is selected from one of amino varnish, acrylic varnish, and polyurethane varnish, and dry it after spraying, and control the drying temperature to be 122° C. and the drying time to be 20 min.

[0063] Among them, the primer coating in S4 is a mixture of epoxy resin, hydroxyalkylamide and polyetheretherketone resin in a mass ratio of 5:1:1.

[0064] The medium powder in S7 includes 100 parts of phenolic epoxy resin, 20 parts of curing agent, 2 parts of leveling agent and 1 part of accelerator.

[0065] Wherein, the curing agent is selected from polyamide curing agents.

[0066] Wherein, the leveling agent is diacetone alcohol.

[0067] Wherein, the accelerator is accelerator DCBS.

[0068] Among them, the abrasive in S5 is brown corundum abrasive.

[0069] Among them, the coating material in S8 is an alloy coating material, including aluminum, nickel and chromium, and argon gas is injected for protection during coating.

[0070] Example 3

[0071] refer to Figure 1 , a vacuum electroplating PVD coating process, specifically comprising the following steps:

[0072] The specific steps include:

[0073] S1. Wheel hub degreasing pretreatment: Select the following weight components: 38 parts of 10% potassium silicate solution, 28 parts of tolyltriazole, 30 parts of pyrrolidone, 38 parts of 10% disodium hydrogen phosphate solution and 15 parts of 15% sodium carbonate solution, and mix them to make a degreasing agent, then place the aluminum alloy wheel hub in the degreasing agent for degreasing, control the degreasing temperature to 45°C, and the degreasing time to 16 minutes;

[0074] S2, pickling: immerse the aluminum alloy wheel hub obtained in S1 in phosphoric acid for pickling for 5 minutes;

[0075] S3, passivation: the aluminum alloy wheel hub obtained in S2 is placed in a chromium-free passivation solution composed of epoxysilane and fluorozirconic acid in a mass ratio of 1:1 for passivation;

[0076] S4, coating with primer powder: placing the substrate in S3 in a vacuum coating chamber and coating the primer powder on its surface by multi-target continuous magnetron sputtering, controlling the vacuum degree in the vacuum coating chamber to 0.0042 Pa and the temperature to 32°C;

[0077] S5. Grinding: Place abrasives in the vibration grinder, so that the vibration grinder drives the abrasives to move relative to the wheel hub for rough grinding, and then use 120# sandpaper to grind the surface of the wheel hub until the surface roughness of the wheel hub is Ra 0.05;

[0078] S6, cleaning and drying: cleaning the wheel hub obtained in S5 with high-pressure water, wherein the high-pressure water used is deionized water, and drying the surface after cleaning;

[0079] S7, dielectric powder coating: spray a layer of translucent dielectric powder coating on the surface of the wheel hub obtained in S6 by electrostatic spraying;

[0080] S8, coating: placing the wheel hub obtained in S7 in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 70V, the current is 60A, the coating time is 230S, the temperature in the vacuum coating chamber is controlled to be 60°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 240mm, the deposition thickness on the wheel hub surface is controlled to be 1um, and the air pressure in the vacuum coating chamber is controlled to be 0.1Pa;

[0081] S9, spray painting: spray the surface of the hub obtained in S8 with a finishing varnish, wherein the finishing varnish is selected from one of amino varnish, acrylic varnish, and polyurethane varnish, and dry it after spraying, and control the drying temperature to be 122° C. and the drying time to be 20 min.

[0082] Among them, the primer coating in S4 is a mixture of epoxy resin, hydroxyalkylamide and polyetheretherketone resin in a mass ratio of 5:1:1.

[0083] The medium powder in S7 includes 100 parts of phenolic epoxy resin, 20 parts of curing agent, 2 parts of leveling agent and 1 part of accelerator.

[0084] Wherein, the curing agent is selected from polyamide curing agents.

[0085] Among them, the leveling agent is Solvesso150.

[0086] Wherein, the promoter is promoter TETD.

[0087] Among them, the abrasive in S5 is brown corundum abrasive.

[0088] Among them, the coating material in S8 is an alloy coating material, including aluminum, nickel and chromium, and argon gas is injected for protection during coating.

[0089] Example 4

[0090] refer to Figure 1 , a vacuum electroplating PVD coating process, specifically comprising the following steps:

[0091] The specific steps include:

[0092] S1. Wheel hub degreasing pretreatment: Select the following weight components: 40 parts of 10% potassium silicate solution, 30 parts of tolyltriazole, 20 parts of pyrrolidone, 38 parts of 10% disodium hydrogen phosphate solution and 15 parts of 15% sodium carbonate solution, and mix them to make a degreasing agent, then place the aluminum alloy wheel hub in the degreasing agent for degreasing, control the degreasing temperature to 45°C, and the degreasing time to 16 minutes;

[0093] S2, pickling: immerse the aluminum alloy wheel hub obtained in S1 in phosphoric acid for pickling for 5 minutes;

[0094] S3, passivation: the aluminum alloy wheel hub obtained in S2 is placed in a chromium-free passivation solution composed of epoxysilane and fluorozirconic acid in a mass ratio of 1:1 for passivation;

[0095] S4, coating with primer powder: placing the substrate in S3 in a vacuum coating chamber and coating the primer powder on its surface by multi-target continuous magnetron sputtering, controlling the vacuum degree in the vacuum coating chamber to 0.0042 Pa and the temperature to 32°C;

[0096] S5. Grinding: Place abrasives in the vibration grinder, so that the vibration grinder drives the abrasives to move relative to the wheel hub for rough grinding, and then use 120# sandpaper to grind the surface of the wheel hub until the surface roughness of the wheel hub is Ra 0.05;

[0097] S6, cleaning and drying: cleaning the wheel hub obtained in S5 with high-pressure water, wherein the high-pressure water used is deionized water, and drying the surface after cleaning;

[0098] S7, dielectric powder coating: spray a layer of translucent dielectric powder coating on the surface of the wheel hub obtained in S6 by electrostatic spraying;

[0099] S8, coating: placing the wheel hub obtained in S7 in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 70V, the current is 60A, the coating time is 230S, the temperature in the vacuum coating chamber is controlled to be 60°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 240mm, the deposition thickness on the wheel hub surface is controlled to be 1um, and the air pressure in the vacuum coating chamber is controlled to be 0.1Pa;

[0100] S9, spray painting: spray the surface of the hub obtained in S8 with a finishing varnish, wherein the finishing varnish is selected from one of amino varnish, acrylic varnish, and polyurethane varnish, and dry it after spraying, and control the drying temperature to be 122° C. and the drying time to be 20 min.

[0101] Among them, the primer coating in S4 is a mixture of epoxy resin, hydroxyalkylamide and polyetheretherketone resin in a mass ratio of 5:1:1.

[0102] The medium powder in S7 includes 100 parts of phenolic epoxy resin, 20 parts of curing agent, 2 parts of leveling agent and 1 part of accelerator.

[0103] Wherein, the curing agent is selected from polyether amine curing agents.

[0104] Among them, the leveling agent is isophorone.

[0105] Wherein, the accelerator is accelerator NOBS.

[0106] Among them, the abrasive in S5 is brown corundum abrasive.

[0107] Among them, the coating material in S8 is an alloy coating material, including aluminum, nickel and chromium, and argon gas is injected for protection during coating.

[0108] Example 5

[0109] refer to Figure 1 , a vacuum electroplating PVD coating process, specifically comprising the following steps:

[0110] The specific steps include:

[0111] S1. Wheel hub degreasing pretreatment: Select the following weight components: 40 parts of 10% potassium silicate solution, 30 parts of tolyltriazole, 20 parts of pyrrolidone, 40 parts of 10% disodium hydrogen phosphate solution and 10 parts of 15% sodium carbonate solution, and mix them to make a degreasing agent, then place the aluminum alloy wheel hub in the degreasing agent for degreasing, control the degreasing temperature to 45°C, and the degreasing time to 16 minutes;

[0112] S2, pickling: immerse the aluminum alloy wheel hub obtained in S1 in phosphoric acid for pickling for 5 minutes;

[0113] S3, passivation: the aluminum alloy wheel hub obtained in S2 is placed in a chromium-free passivation solution composed of epoxysilane and fluorozirconic acid in a mass ratio of 1:1 for passivation;

[0114] S4, coating with primer powder: placing the substrate in S3 in a vacuum coating chamber and coating the primer powder on its surface by multi-target continuous magnetron sputtering, controlling the vacuum degree in the vacuum coating chamber to 0.0042 Pa and the temperature to 32°C;

[0115] S5. Grinding: Place abrasives in the vibration grinder, so that the vibration grinder drives the abrasives to move relative to the wheel hub for rough grinding, and then use 120# sandpaper to grind the surface of the wheel hub until the surface roughness of the wheel hub is Ra 0.05;

[0116] S6, cleaning and drying: cleaning the wheel hub obtained in S5 with high-pressure water, wherein the high-pressure water used is deionized water, and drying the surface after cleaning;

[0117] S7, dielectric powder coating: spray a layer of translucent dielectric powder coating on the surface of the wheel hub obtained in S6 by electrostatic spraying;

[0118] S8, coating: placing the wheel hub obtained in S7 in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 70V, the current is 50A, the coating time is 230S, the temperature in the vacuum coating chamber is controlled to be 80°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 240mm, the deposition thickness on the wheel hub surface is controlled to be 2um, and the air pressure in the vacuum coating chamber is controlled to be 0.1Pa;

[0119] S9, spray painting: spray the surface of the hub obtained in S8 with a finishing varnish, wherein the finishing varnish is selected from one of amino varnish, acrylic varnish, and polyurethane varnish, and dry it after spraying, and control the drying temperature to be 122° C. and the drying time to be 20 min.

[0120] Among them, the primer coating in S4 is a mixture of epoxy resin, hydroxyalkylamide and polyetheretherketone resin in a mass ratio of 5:1:1.

[0121] The medium powder in S7 includes 100 parts of phenolic epoxy resin, 20 parts of curing agent, 2 parts of leveling agent and 1 part of accelerator.

[0122] The surface hardness and peel strength of the wheel hubs obtained in Examples 1 to 5 were tested, and a common wheel hub using vapor deposition was selected as a control group for the experiment. The experimental results are shown in the following table (the control group is used as a reference):

[0123] Table 1

[0124] Surface hardness Peel strength cost Pollutant isolation capability Control group 100％ 100％ 100％ 100％ Example 1 130％ 125％ 46％ 130％ Example 2 133％ 126％ 46％ 124％ Example 3 131％ 137％ 45％ 135％ Example 4 140％ 138％ 50％ 135％ Example 5 150％ 146％ 39％ 138％

[0125] Analysis shows that embodiment 5 is a better embodiment among the above five embodiments.

[0126] 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 vacuum electroplating PVD coating process, characterized in that: The specific steps include: S1. Wheel hub degreasing pretreatment: select the following weight components: 30-40 parts of 10% potassium silicate solution, 20-30 parts of tolyltriazole, 20-30 parts of pyrrolidone, 30-40 parts of 10% disodium hydrogen phosphate solution and 10-15 parts of 15% sodium carbonate solution, and mix them to make a degreasing agent, then place the aluminum alloy wheel hub in the degreasing agent for degreasing, control the degreasing temperature to 40-45°C, and the degreasing time to 15-20min; S2, pickling: immersing the aluminum alloy wheel hub obtained in S1 in phosphoric acid for pickling for 5-10 minutes; S3, passivation: the aluminum alloy wheel hub obtained in S2 is placed in a chromium-free passivation solution composed of epoxysilane and fluorozirconic acid in a mass ratio of 1:1 for passivation; S4, coating with primer powder: placing the substrate in S3 in a vacuum coating chamber and coating the primer powder on its surface by multi-target continuous magnetron sputtering, controlling the vacuum degree in the vacuum coating chamber to 0.004-0.0045 Pa and the temperature to 30-35° C.; S5. Grinding: Place abrasives in the vibration grinder, so that the vibration grinder drives the abrasives to move relative to the wheel hub for rough grinding, and then use 120# sandpaper to grind the surface of the wheel hub until the surface roughness of the wheel hub is Ra 0.05; S6, cleaning and drying: cleaning the wheel hub obtained in S5 with high-pressure water, wherein the high-pressure water used is deionized water, and drying the surface after cleaning; S7, coating with dielectric powder: spraying a layer of translucent dielectric powder coating on the surface of the hub obtained in S6 by electrostatic spraying; S8, coating: placing the wheel hub obtained in S7 in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 60-70V, the current is 50-60A, the coating time is 220-250S, the temperature in the vacuum coating chamber is controlled to be 60-80°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 200-240mm, the deposition thickness on the wheel hub surface is controlled to be 1-2um, and the air pressure in the vacuum coating chamber is controlled to be 0.1-2Pa; S9, spray painting: spray a finishing varnish on the surface of the hub obtained in S8, wherein the finishing varnish is selected from one of amino varnish, acrylic varnish, and polyurethane varnish, and dry after spraying, and control the drying temperature to be 120-125° C. and the drying time to be 20-25 min.

2. The vacuum electroplating PVD coating process according to claim 1, characterized in that: The primer coating in S4 is a mixture of epoxy resin, hydroxyalkylamide and polyetheretherketone resin in a mass ratio of 5:1:

1.

3. The vacuum electroplating PVD coating process according to claim 1, characterized in that: The medium powder in S7 includes 100-120 parts of phenolic epoxy resin, 20-30 parts of curing agent, 2-4 parts of leveling agent, and 1-3 parts of accelerator.

4. The vacuum electroplating PVD coating process according to claim 3, characterized in that: The curing agent is selected from polyetheramine curing agents and polyamide curing agents.

5. The vacuum electroplating PVD coating process according to claim 3, characterized in that: The leveling agent is one of isophorone, diacetone alcohol and Solvesso 150.

6. The vacuum electroplating PVD coating process according to claim 3, characterized in that: The accelerator is one of accelerator TBTD, accelerator NOBS, accelerator TETD and accelerator DCBS.

7. The vacuum electroplating PVD coating process according to claim 1, characterized in that: The abrasive in S5 is a mixture of one or more of brown corundum abrasive, black silicon carbide abrasive, green silicon carbide abrasive, cubic silicon carbide abrasive, and cerium silicon carbide abrasive.

8. The vacuum electroplating PVD coating process according to claim 1, characterized in that: During the S8 coating, the wheel hub obtained in the S7 is placed in a vacuum coating chamber for multi-arc ion coating, wherein the voltage of the arc ion coating power supply is 63-66V, the current is 54-58A, the coating time is 230-240S, the temperature in the vacuum coating chamber is controlled to be 63-70°C, the distance between the target material and the wheel hub in the vacuum coating chamber is controlled to be 230-240mm, the deposition thickness on the surface of the wheel hub is controlled to be 1-2um, and the air pressure in the vacuum coating chamber is controlled to be 0.1-2Pa.

9. The vacuum electroplating PVD coating process according to claim 1, characterized in that: The plating material in S8 is an alloy plating material including aluminum, nickel and chromium, and argon gas is injected during the plating process for protection.

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