阅读说明：本技术 一种提高金属磷化处理中磷化膜连续致密性的预处理工艺 (Pretreatment process for improving continuous compactness of phosphating film in metal phosphating treatment ) 是由 苗雪峰 于 2020-07-27 设计创作，主要内容包括：本发明公开了一种提高金属磷化处理中磷化膜连续致密性的预处理工艺,涉及金属表面处理技术领域,具体工艺如下：1)将金属工件放置于容器中,将配置的混合液倒入容器中,进行加热处理以及退火处理；2)将待处理的金属工件作为基体材料进行溅射处理；3)配制涂膜溶液；4)将预处理金属工件浸入到涂膜溶液中,提拉浸渍后进行热处理即可。本发明提供的金属工件的预处理工艺,一方面可以保证金属工件表面磷化膜的顺利形成,同时可以使金属工件磷化后表面晶体生长均一性得到提升,使得磷化膜结构层次紧密、均匀,从而有助于提高磷化处理的效果,有助于实现金属工件表面形成连续致密结构的磷化膜,从而提高了金属工件的耐腐蚀性能。(The invention discloses a pretreatment process for improving continuous compactness of a phosphating film in metal phosphating treatment, which relates to the technical field of metal surface treatment and comprises the following specific steps: 1) placing the metal workpiece in a container, pouring the prepared mixed liquid into the container, and carrying out heating treatment and annealing treatment; 2) taking a metal workpiece to be treated as a base material to carry out sputtering treatment; 3) preparing a coating solution; 4) and (3) immersing the pretreated metal workpiece into the coating solution, and carrying out heat treatment after the metal workpiece is subjected to pulling and immersion. The pretreatment process for the metal workpiece provided by the invention can ensure the smooth formation of the phosphating film on the surface of the metal workpiece, and can improve the uniformity of surface crystal growth after the metal workpiece is phosphated, so that the phosphating film has compact and uniform structure, the phosphating treatment effect is improved, the continuous compact structure phosphating film is formed on the surface of the metal workpiece, and the corrosion resistance of the metal workpiece is improved.)

1. A pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating is characterized by comprising the following specific steps of:

1) respectively ultrasonically cleaning a metal workpiece for 20-30min by using acetone, distilled water and ethanol after acid cleaning, drying after cleaning, placing the metal workpiece in a container, dissolving a proper amount of thioacetamide in deionized water, stirring for 15-20min, adding a proper amount of potassium tartrate, continuously stirring for 30-40min, adding a proper amount of ethanol into the mixed solution while stirring, then quickly pouring the mixed solution into the container, carrying out constant-temperature heating treatment at the temperature of 150-160 ℃ for 15-18h, cooling to room temperature after the reaction is finished, taking out the metal workpiece, repeatedly washing the metal workpiece by using deionized water, and annealing to obtain a metal workpiece to be treated;

2) horizontally placing a metal workpiece to be treated on a magnetron sputtering platform as a base material, pre-sputtering for 2-3min, then sequentially sputtering tantalum, nickel chromium and iron, and setting the vacuum degree of a deposition system to be 3 multiplied by 10^-4-8×10^-4Pa, setting the temperature of the substrate at 200-250 ℃ in the deposition processAfter the sputtering treatment is finished, obtaining a pretreated metal workpiece;

3) weighing a proper amount of ferric chloride, adding the ferric chloride into absolute ethyl alcohol, stirring to dissolve, adding a proper amount of acetylacetone, stirring uniformly, heating in a water bath at 50-60 ℃, adding a proper amount of epoxy chloroethane under the stirring condition, and stirring for 5-6 hours under heat preservation to obtain a coating solution;

4) dipping the pretreated metal workpiece into the coating solution by adopting a pulling and dipping method, controlling the pulling speed to be 8-10cm/min, repeatedly pulling for 2-3 times, drying the pretreated metal workpiece at 110 ℃ of 100-.

2. The pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating according to claim 1, wherein in the process step 1), the acid washing step is as follows: soaking with 120-160g/L hydrochloric acid for 3-5min, soaking with 150-180g/L hydrochloric acid for 5-7min, soaking with 100-130g/L hydrochloric acid for 3-5min, and washing with high-pressure water until the eluate is neutral.

3. The pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating treatment according to claim 1, wherein in the process step 1), the mass-to-volume ratio of thioacetamide to deionized water is 4-5 g/mL; the molar ratio of thioacetamide to potassium tartrate is 2: 1; the ethanol and the deionized water have equal volume.

4. The pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating as claimed in claim 1, wherein in the process step 1), the stirring rotating speed is all 100-150 r/min; the temperature of the annealing treatment is 300-320 ℃, and the treatment time is 30-35 min; the temperature rise rate of the annealing treatment is 4-6 ℃/min.

5. The pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating as claimed in claim 1, wherein in the process step 2), the sputtering gas is pure argon; in the sputtering deposition process, the thickness of the tantalum and the nickel-chromium is 50-80nm, and the thickness of the iron is 500-550 nm.

6. The pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating as claimed in claim 1, wherein in the process step 3), the mass-to-volume ratio of ferric trichloride to absolute ethyl alcohol is 1:6-8 g/mL; the molar ratio of the acetylacetone to the ferric trichloride is 2: 1; the addition amount of the epoxy chloroethane is 5-8% of the volume of the absolute ethyl alcohol.

7. The pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating as claimed in claim 1, wherein in the process step 3), the stirring rotating speed is 100-130 r/min.

8. The pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating treatment according to claim 1, wherein in the process step 4), the environment condition of the pulling and dipping method is 20-24 ℃ at room temperature and 70-75% of relative humidity; the drying time is 1-2 h.

Technical Field

The invention belongs to the technical field of metal surface treatment, and particularly relates to a pretreatment process for improving continuous compactness of a phosphating film in metal phosphating.

Background

Before the metal is sprayed and coated, the surface of the metal needs to be subjected to conversion treatment so as to generate a conversion coating. The conversion film comprises a phosphating film, a passivation film, an organic film, a rare earth conversion film, a sol silane film and the like. The preparation of the phosphate film is to put metal parts into a salt solution containing Zn, Ni, Mn, Fe and other specific acid phosphates as main components, simultaneously add various composite additives, and generate a phosphate conversion film with a certain thickness and difficult water solubility on the surfaces of the metal parts through chemical treatment. The purpose of the phosphorization is mainly as follows: the base metal is protected, and the metal is prevented from being corroded to a certain extent; the primer is used for priming before painting, and the adhesive force and the corrosion resistance of a paint film layer are improved; plays a role in friction reduction and lubrication in the metal cold working process.

Disclosure of Invention

The invention aims to provide a pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating treatment aiming at the existing problems.

The invention is realized by the following technical scheme:

a pretreatment process for improving the continuous compactness of a phosphating film in metal phosphating treatment comprises the following specific steps:

1) respectively ultrasonically cleaning a metal workpiece for 20-30min by using acetone, distilled water and ethanol after acid cleaning, drying after cleaning, placing the metal workpiece in a container, dissolving thioacetamide in deionized water according to the mass-to-volume ratio of 4-5g/mL, stirring for 15-20min at the speed of 150r/min, adding a proper amount of potassium tartrate according to the molar ratio of 2:1 of the thioacetamide to the potassium tartrate, continuously stirring for 30-40min, adding ethanol with the same volume as the mixed solution while stirring, then quickly pouring the mixed solution into the container, carrying out constant-temperature heating treatment for 15-18h at the temperature of 150 ℃ and 160 ℃, cooling to room temperature after reaction is finished, taking out the metal workpiece, repeatedly cleaning by using the deionized water, controlling the heating rate of annealing treatment to be 4-6 ℃/min, annealing at 300-320 ℃ for 30-35min to obtain a metal workpiece to be treated; according to the invention, thioacetamide is used as a sulfur source, potassium tartrate is used as an antimony source, antimony sulfide particles are tightly connected with one another to form an antimony sulfide particle film in a cellular shape on the surface of a metal workpiece through a hydrothermal reaction, and the formed particle film can effectively fill grooves and gaps on the surface of the metal workpiece, so that the smoothness of the surface of the metal workpiece is improved, and the antimony sulfide particles form uniformly distributed arched bulges on the surface of the film, can be used as deposition sites of nano particles in subsequent sputtering deposition, and is beneficial to improving the bonding strength between a deposition layer and the antimony sulfide particle film; after subsequent annealing treatment, the compact state of the bottom of the antimony sulfide granular film is favorably improved, and the antimony sulfide granular film is well contacted with a metal workpiece, so that the bonding strength between the antimony sulfide granular film and the metal workpiece can be improved;

2) horizontally placing a metal workpiece to be treated on a magnetron sputtering platform as a base material, adopting argon as sputtering lifting, firstly pre-sputtering for 2-3min, then sequentially sputtering tantalum, nickel-chromium and iron, and setting the vacuum degree of a deposition system to be 3 multiplied by 10^-4-8×10^{- 4}Pa, setting the temperature of the matrix to be 200-550 ℃ in the deposition process, and obtaining a pretreated metal workpiece with the thickness of 50-80nm of tantalum and nickel-chromium and the thickness of 500-550nm of iron after the sputtering treatment is finished; in the application, the metal workpiece is subjected to pre-sputtering treatment, so that pollutants on the surface of the metal workpiece can be removed, and then the metal workpiece is subjected to gold sputtering treatmentBelong to work piece surface and sputter deposit tantalum in proper order, nickel chromium and iron, deposit under high temperature, make atomic surface diffusion length increase, promote crystallization, make deposit layer surface smooth, the sedimentary deposit is after with the contact of bonderizing liquid, can take place interface migration in interface department, because the sedimentary deposit is the multilayer structure who forms by nanocrystalline grain close arrangement, the resistance effect is exerted to the grain boundary after the multilayer nanocrystalline grain of intensive arrangement and grain boundary contact, the migration of grain boundary has been hindered, make metal work piece bonderizing back surface crystalline grain growth restrain, thereby the overgrowth of crystalline grain has been restrained, make work piece bonderizing back surface crystal growth homogeneity obtain promoting, bonderizing membrane structure level is inseparable, it is even, thereby help improving the effect of bonderizing, the iron on sedimentary deposit top layer can dissolve in the bonderizing liquid simultaneously, participate in the formation of bonderizing membrane, thereby can compensate metal work piece surface because contain the phenomenon that the nano-deposition layer leads to (ii) occurs;

3) adding ferric chloride into absolute ethyl alcohol according to the mass-to-volume ratio of 1:6-8g/mL, stirring and dissolving at 130r/min of 100-;

4) immersing the pretreated metal workpiece into the coating solution by adopting a pulling and dipping method in an environment with the room temperature of 20-24 ℃ and the relative humidity of 70-75%, controlling the pulling speed to be 8-10cm/min, repeatedly pulling for 2-3 times, drying the pretreated metal workpiece for 1-2h at the temperature of 100-110 ℃, pretreating for 30-40min at the temperature of 200-220 ℃, thermally treating for 30-40min at the temperature of 450-500 ℃, and naturally cooling to the room temperature to finish the pretreatment process of the metal workpiece; according to the invention, the film consisting of the iron oxide is formed on the surface of the pretreated metal workpiece through the film drawing and heat treatment, the formed compact iron oxide film can block air, and the phenomenon that iron in a deposition layer is oxidized by oxygen in the air to influence the phosphating effect is avoided, so that the treated metal workpiece can be placed for a period of time and then subjected to phosphating treatment, and the film drawing times are less, so that the formed film is thinner and can be dissolved easily in phosphating solution to disappear.

Further, the pickling step is as follows: soaking with 120-160g/L hydrochloric acid for 3-5min, soaking with 150-180g/L hydrochloric acid for 5-7min, soaking with 100-130g/L hydrochloric acid for 3-5min, and washing with high-pressure water until eluate is neutral

Compared with the prior art, the invention has the following advantages:

according to the pretreatment process of the metal workpiece, provided by the invention, the antimony sulfide particle film is formed on the surface of the metal workpiece through hydrothermal reaction, the deposition layer is formed through sputtering deposition, and the iron oxide film is formed through pulling the coating film, so that the formed multilayer structure can ensure the smooth formation of the phosphating film on the surface of the metal workpiece, and the uniformity of surface crystal growth after phosphating the metal workpiece can be improved, so that the phosphating film has compact and uniform structure, the phosphating treatment effect is improved, the phosphating film with a continuous compact structure is formed on the surface of the metal workpiece, and the corrosion resistance of the metal workpiece is improved.

Detailed Description

The present invention will be further described with reference to specific embodiments.