CN111471997A

CN111471997A - Metal material containing layered double hydroxide composite coating and plating layer and preparation method thereof

Info

Publication number: CN111471997A
Application number: CN202010275518.1A
Authority: CN
Inventors: 谢治辉; 李艳秋
Original assignee: China West Normal University
Current assignee: China West Normal University
Priority date: 2020-04-09
Filing date: 2020-04-09
Publication date: 2020-07-31
Anticipated expiration: 2040-04-09
Also published as: CN111471997B

Abstract

The invention discloses a metal material containing a layered double hydroxide composite coating and plating layer and a preparation method thereof, wherein the preparation method comprises the following steps: (1) adding a basic coating layer on a base material; (2) the basic coating layer is treated to be compounded with the layered double hydroxide. The metal material obtained by the invention has higher corrosion resistance and corrosion and penetration resistance, and simultaneously has good electric conduction, heat conduction and magnetic conduction properties and good mechanical properties.

Description

Metal material containing layered double hydroxide composite coating and plating layer and preparation method thereof

Technical Field

The invention relates to the technical field of layered double hydroxides.

Background

In order to overcome the defects of the properties of some metal or nonmetal materials or endow the metal or nonmetal materials with special physicochemical properties, technical means of coating a certain coating on the surface of the materials are commonly used in the prior art. For example, in order to improve the hardness, corrosion resistance and friction and abrasion resistance of the magnesium alloy, coatings such as aluminum, aluminum oxide, tungsten carbide and the like are prepared on the surface of the magnesium alloy by using methods such as plasma spraying, laser remelting, cold spraying and the like; in order to improve the thermal shock resistance of a high-speed steel matrix, different CrTiAlN gradient coatings are prepared on the surface of the high-speed steel by adopting a magnetron sputtering technology; in order to improve the surface hardness and the electric conductivity of wood or plastic, a metal coating such as silver, copper and the like is formed on the surface of the wood or plastic by adopting a method combining chemical plating and electrodeposition; in order to improve the magnetic conductivity of the substrate material, alloy coatings such as Fe-Co, Ni-Fe, Ni-Co and the like are prepared.

After the coating is applied, the corrosion risk of the material as a whole will be largely borne by the coating, and it is therefore important to improve the corrosion resistance of the coating. On the other hand, when the coating itself has good corrosion resistance, it is necessary to block the penetration of corrosion into the substrate, i.e., to reduce microscopic defects of the coating such as pores and the like to reduce the risk of penetration of the corrosion medium from the coating to the substrate.

The prior art has worked somewhat in both of these respects, such as continuously using coatings with greater corrosion resistance to improve the corrosion resistance of the coating itself. Among them, the metal or alloy material with stronger corrosion ability usually accompanies the increase of cost, the increase of processing difficulty, the increase of bonding difficulty with the substrate material, the decrease of bonding effect, the decrease of material dimensional stability, etc.; the metal oxide, metal hydroxide or nonmetal with stronger corrosion capability generally reduces the electric conduction, magnetic conduction and thermal conduction performance of the material, and simultaneously has the problems of increased processing difficulty, increased bonding difficulty with the substrate material and reduced bonding effect.

In the aspect of reducing the porosity of the coating to block the penetration of corrosion, part of the prior art adopts a heat treatment mode for the coating, but the heat treatment mode cannot eliminate the pores and can cause certain influence on the thermal or mechanical properties of the whole material. In part of the prior art, a mode of properly enhancing the thickness of a plating layer is adopted so as to reduce the probability of forming through holes; however, in practical applications, the size of the workpiece is limited and the desired coating thickness cannot be achieved.

In addition, some of the prior arts hope to improve the corrosion resistance by passivating the coating material, which is typified by chromate passivation process, but the passivation material in the similar process often contains elements which are harmful to human body or ecology, such as chromium, and the like, so that the method is difficult to be popularized and applied.

Disclosure of Invention

The invention aims to provide a metal material containing a plating layer and layered double hydroxide. The material has high corrosion resistance and corrosion and penetration resistance, the surface materials have compact structures, the bonding performance between the surface materials and the substrate material is good, and the material has good electric conduction, heat conduction and magnetic conduction performance and good mechanical performance.

The invention also aims to provide a preparation method of the metal material.

The invention firstly provides the following technical scheme:

a preparation method of a metal material containing a layered double hydroxide composite coating layer comprises the following steps:

(1) adding a basic coating layer on a base material;

(2) the basic coating layer is treated to be compounded with the layered double hydroxide.

According to some embodiments of the invention, step (1) comprises pre-treatment of the substrate material. Such as mechanical grinding, degreasing, acid washing, and alkali washing of the substrate material.

According to some embodiments of the invention, the treatment of step (2) is selected from one or more of in-situ growth, co-deposition, electrochemical deposition, spin coating, and ion exchange.

Wherein the in-situ growth refers to a process that raw materials react with each other to form double hydroxide on the basic coating layer.

Co-deposition refers to the process of mixing two or more solutions to form a precipitate or slurry that can be deposited on a base material.

In one embodiment of the method for preparing the metal material containing the layered double hydroxide composite coating layer, a divalent and trivalent metal solution A is prepared, an alkaline solution B of sodium carbonate is prepared, the solution B is dropwise added into the solution A to form a slurry C, and the slurry C and the substrate material treated in the step (1) are placed in a reaction kettle for reaction.

According to some embodiments of the invention, the treatment of step (2) is hydrothermal.

According to some embodiments of the invention, the processing of step (2) comprises: dipping the metal material containing the basic coating layer in a hydrothermal deposition solution; wherein the hydrothermal deposition solution contains an anion and a metal cation selected from divalent metal cations and/or trivalent metal cations.

According to some embodiments of the invention, the divalent metal cation is selected from one or more of magnesium, nickel, cobalt, zinc and copper.

According to some embodiments of the invention, the trivalent metal cation is selected from one or more of aluminum ion, chromium ion, iron ion and scandium ion.

According to some embodiments of the invention, the anion is selected from one or more of carbonate, nitrate, chloride, hydroxide, sulfate, phosphate, molybdate, and benzenetetraoate.

According to some embodiments of the invention, the hydrothermal deposition solution contains magnesium nitrate, aluminum nitrate, and sodium nitrate.

Preferably, the pH of the hydrothermal deposition solution is 9-13;

preferably, the concentration of magnesium nitrate in the hydrothermal deposition solution is 12-18 g/L.

Preferably, the concentration of aluminum nitrate in the hydrothermal deposition solution is 20-35 g/L.

Preferably, the concentration of sodium carbonate in the hydrothermal deposition solution is 8-12 g/L.

According to some embodiments of the invention, the hydrothermal deposition solution contains basic nickel carbonate, aluminum nitrate, and sodium carbonate.

Preferably, the pH of the hydrothermal deposition solution is 9-13;

preferably, the concentration of the basic nickel carbonate in the hydrothermal deposition solution is 6-12 g/L.

According to some embodiments of the invention, the hydrothermal deposition solution comprises zinc nitrate and sodium nitrate.

Preferably, the pH of the hydrothermal deposition solution is 9-13.

Preferably, the concentration of zinc nitrate in the hydrothermal deposition solution is 0.5-2 g/L.

Preferably, the concentration of sodium nitrate in the hydrothermal deposition solution is 8-12 g/L.

According to some embodiments of the invention, the temperature of the impregnation is 80 to 150 ℃.

Preferably, the impregnation temperature is 90 to 130 ℃.

According to some embodiments of the invention, the time of the impregnation is between 6 and 48 hours.

Preferably, the time for the impregnation is 12 to 36 hours.

Or preferably, the time for the impregnation is 12-24 h.

According to some embodiments of the present invention, the hydrothermal deposition solution comprises a solution a and a solution B, wherein the solution a comprises ferric ions saturated with carbon dioxide and the solution B is an aqueous solution saturated with carbon dioxide and adjusted to a pH of 9.0 to 11 with sodium hydroxide.

According to some embodiments of the invention, the ferric ion is present at a concentration of 0.08-0.12 g/L.

According to some embodiments of the invention, the pH of solution a is 4.0 to 6.0.

According to some embodiments of the invention, the immersion temperature in solution A is 45-55 ℃.

According to some embodiments of the invention, the immersion time in solution a is 30-60 min.

According to some embodiments of the invention, the immersion temperature in solution B is 45-55 ℃.

According to some embodiments of the invention, the immersion time in solution B is 30-60 min.

According to some embodiments of the invention, the substrate material is selected from one or more of a metal, an alloy, and a metal and non-metal composite.

According to some embodiments of the invention, the substrate material is selected from one or more of zinc, magnesium, aluminum and alloys thereof.

According to some embodiments of the invention, the base coating material is selected from one or more of nickel, aluminum, copper, silver, cobalt, cadmium, tin, zinc, iron, chromium, titanium, lead, antimony, palladium, gold, aluminum, and alloys thereof.

According to some embodiments of the invention, the base coating layer is applied in an additive manner selected from one or more of electroplating, thermal spraying, diffusion coating, build-up welding, hot dip coating, electroless plating, physical vapor deposition, chemical vapor deposition, ion plating, vacuum evaporation, sputter coating and high energy beam surface modification.

The invention also provides a metal material prepared according to the preparation method or the preferred and specific embodiment.

The metal material comprises a composite coating layer compounded by a basic coating layer and a layered double hydroxide (L a layer double hydroxide, L '&gTt transition = L' &gTt L &lTt/T &gTt DH) with a nano structure, wherein the base coating layer, namely the metal coating layer, is modified by L DH through the composite coating layer, so that a covering layer with composite performance is formed on the surface of the metal material.

Drawings

FIG. 1 is a surface microscopic structure view of a composite coating layer of a product obtained in example 1 of the present invention;

FIG. 2 is a surface microscopic structure diagram (different magnification) of a composite coating layer of a product obtained in example 1 of the present invention;

FIG. 3 is a comparison graph of polarization curves of the product obtained in example 1 of the present invention and a nickel-plated magnesium alloy;

FIG. 4 is a comparison graph of the electrochemical impedance spectrum of the product obtained in example 1 of the present invention and a nickel-plated magnesium alloy.

Detailed Description

The present invention is described in detail below with reference to the following embodiments and the attached drawings, but it should be understood that the embodiments and the attached drawings are only used for the illustrative description of the present invention and do not limit the protection scope of the present invention in any way. All reasonable variations and combinations that fall within the spirit of the invention are intended to be within the scope of the invention.

The alkaline solution is one or more of 15-60 g/L sodium hydroxide solution, 5-20 g/L phosphate solution and 20-40 g/L carbonate solution;

the activating solution is 10-300m L/L hydrofluoric acid solution or 30-150 g/L ammonium bifluoride solution;

the chemical nickel plating solution comprises 20-30 g/L of nickel sulfate hexahydrate, 20-30 g/L of sodium hypophosphite, 2-10 g/L of citric acid or citrate, 5-15 g/L of ammonium bifluoride, 10-15m L/L or 5-15 g/L of hydrofluoric acid or alkali metal fluoride, 0.5-1.5 mg/L of thiourea and the pH value of ammonia water is adjusted to be 4.5-6.0.

Example 1

Preparing a metal material by:

(1) putting the polished magnesium alloy part into acetone, performing normal-temperature ultrasonic treatment for 10-15min, washing and soaking the polished magnesium alloy part for 10-15min by adopting the alkaline solution at the temperature of 55-65 ℃, then performing acid cleaning for 30-90s by adopting 100-500m L/L phosphoric acid solution, and then treating for 5-15min by adopting an activating solution;

(2) immersing the magnesium alloy part subjected to the step (1) into a chemical nickel plating solution, and plating for 60-120min at 80-90 ℃;

(3) and (3) soaking the magnesium alloy part subjected to the step (2) into the hydrothermal deposition solution, reacting at 90-130 ℃ for 12-36h, taking out the part after reaction, washing with distilled water, and drying at 65 ℃ overnight.

Wherein the hydrothermal deposition solution comprises 12-18 g/L of magnesium nitrate, 20-35 g/L of aluminum nitrate, 8-12 g/L of sodium carbonate and 9-13 of pH.

By characterizing the product obtained in this example, the microstructure shown in fig. 1-2 was obtained, and it can be seen that the product formed a uniformly penetrating, sheet-like L DH film layer on the surface of the base nickel layer.

Example 2

A magnesium alloy part containing a composite plating layer was obtained by the same procedures (1) to (3) as in example 1, wherein the composition of the hydrothermal deposition solution was 6 to 12 g/L of basic nickel carbonate, 20 to 35 g/L of aluminum nitrate, 8 to 12 g/L of sodium carbonate, and pH was 9 to 13.

Example 3

A magnesium alloy member after pretreatment was obtained by the same procedure (1) as in example 1, after which:

(2) immersing the component in nickel pre-plating solution, and plating for 5-10min by pulse current method with current density of 2-4A/dm²The duty ratio is 10-30%, the frequency is 2-100Hz, the temperature is 25 ℃, the electroplating solution comprises 80-120 g/L of nickel sulfate, 40-60 g/L of ammonium citrate, 40-45m L/L of 25-28% ammonia water, and the pH is 8-10, then the parts are continuously electroplated for 15-30min in the electroplating solution at the temperature of 45-65 ℃ by adopting a pulse current method, wherein the electroplating solution comprises 80-120 g/L of nickel sulfate, 40-60 g/L of ammonium citrate, 10-20 g/L of sodium carbonate, 10-20 g/L of ammonium bifluoride, and the pH is 5-8;

(3) a magnesium alloy member containing a composite plating layer was obtained by the same procedure (3) as in example 1, wherein the hydrothermal deposition solution used was the same as in example 2.

Example 4

Preparing a metal material by:

(1) putting the polished aluminum alloy part into acetone, performing normal temperature ultrasonic treatment for 10-15min, washing and soaking the aluminum alloy part for 10-15min at 55-65 ℃ by adopting the alkaline solution, then soaking the aluminum alloy part into a phosphorylation liquid, and performing acid washing at 50-60 ℃ for 15-30min, wherein the phosphorylation liquid comprises 10-15 g/L of sodium monohydrogen phosphate, 10-15 g/L of zinc nitrate, 3-5 g/L of sodium nitrite, 1-3 g/L of sodium fluoride, and the pH value is 4;

(2) - (3): the aluminum alloy part containing the composite coating is obtained by adopting the steps (2) and (3) which are the same as the steps in the example 1, wherein the hydrothermal deposition solution is the same as the step in the example 1.

Example 5

Preparing a metal material by:

(1) carrying out sand blasting treatment on the magnesium sheet by using clean, dry and non-greasy phosphorus cast iron sand and corundum sand with the granularity of about 0.5-1.5mm so as to clean and dry the surface of the magnesium sheet;

(2) preparing an aluminum coating on the surface of the magnesium sheet by a thermal spraying method, wherein an aluminum wire with the purity of more than 99.5 percent and the diameter of 3mm is used as a spraying material, and the gas working pressure is as follows: 0.4-0.5MPa of oxygen, 0.06-0.1MPa of acetylene, 0.5-0.7MPa of compressed air and 0.2-0.5MPa of inert protective gas;

(3) and (3) soaking the sample sprayed with the aluminum layer in a hydrothermal deposition solution at 90-95 ℃ for 12-24h, taking out the part after the reaction is finished, washing the part with distilled water, and drying the part at 65 ℃ overnight.

Wherein the hydrothermal deposition solution comprises zinc nitrate 0.5-2 g/L, sodium nitrate 8-12 g/L, and pH 9-13.

Example 6

Preparing a metal material by:

(1) putting the polished steel and iron parts into acetone, performing normal temperature ultrasonic treatment for 10-15min, soaking the steel and iron parts in the alkaline solution at 55-65 ℃ for 10-15min, and then performing acid pickling at 40-60 ℃ for 10-20min by using acid pickling, wherein the acid solution comprises the following components: 15% sulfuric acid and 0.1% thiourea, followed by immersion treatment with a plating assistant at 55-65 ℃ for 5-10 min: the plating assistant agent comprises the following components: 15 to 25 percent of ammonium chloride and 2.5 to 3.5 percent of zinc chloride;

(2) drying and preheating the pretreated steel piece to the temperature of 110-190 ℃, quickly immersing the steel piece into the zinc melt preheated to the temperature of 450-470 ℃ for 1-2min, and carrying out the next step after cooling to the room temperature;

(3) and (3) immersing the steel part subjected to the step (2) in the solution A at the temperature of 45-55 ℃ for 30-60min, then immersing the steel part in the solution B at the temperature of 45-55 ℃ for 30-60min, taking out the sample after the hydrothermal reaction, washing the sample with distilled water, and drying the sample at the temperature of 65 ℃ overnight.

Wherein the A solution is composed of carbon dioxide saturated ferric ion solution with the concentration of 0.08-0.12 g/L and the pH value is 4.0-6.0, and the B solution is composed of carbon dioxide saturated water solution with the pH value adjusted to 9.0-11 by sodium hydroxide.

The same microscopic characterization of the products of examples 2-6 as the product of example 1 all showed that a uniformly penetrating, laminar L DH film layer was formed on the surface of the base metal material.

The products of examples 1 to 6 were immersed in 3.5% by mass of NaCl solution using a three-electrode system in which the reference electrode was a saturated calomel electrode and the counter electrode was a platinum plate electrode, and corrosion resistance tests were conducted by a self-corrosion polarization curve and electrochemical impedance spectroscopy, whereby it was found that the self-corrosion current of the obtained products was reduced to 80nA/cm²The metal plating layer is reduced by more than 2 orders of magnitude relative to the material only containing the metal plating layer; the impedance modulus value of the obtained product at low frequency is improved by more than 1 order of magnitude relative to the material only containing the metal coating, which shows that the product of the invention has excellent corrosion resistance.

As can be seen in the comparison of the polarization curves of the product of example 1 shown in FIG. 3 and the magnesium alloy containing only nickel plating, the magnesium alloy containing a single nickel plating layer had a self-corrosion current density of about 8 μ A/cm²The product of example 1 reduced the self-corrosion current density to about 70nA/cm²The reduction is as much as 2 orders of magnitude.

Or as can be seen in the comparison of the EIS spectra of the product of example 1 and the magnesium alloy containing only nickel plating shown in fig. 4, the impedance mode value of the product of example 1 at low frequency is much higher, up to 1 order of magnitude or more, than that of the magnesium alloy containing a single nickel plating layer.

The above examples are merely preferred embodiments of the present invention, and the scope of the present invention is not limited to the above examples. All technical schemes belonging to the idea of the invention belong to the protection scope of the invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention, and such modifications and embellishments should also be considered as within the scope of the invention.

Claims

1. The preparation method of the metal material containing the layered double hydroxide composite coating layer is characterized by comprising the following steps of: the method comprises the following steps:

(1) adding a basic coating layer on a base material;

(2) treating the basic coating layer to enable the basic coating layer to be compounded with the layered double hydroxide;

preferably, the substrate material is pretreated first.

2. The method of claim 1, wherein: the treatment of the step (2) is selected from one or more of in-situ growth, codeposition, electrochemical deposition, spin coating and ion exchange; preferably, the treatment in step (2) is a hydrothermal method.

3. The method of claim 2, wherein: the processing of step (2) comprises:

dipping the metal material containing the basic coating layer in a hydrothermal deposition solution; wherein the hydrothermal deposition solution contains an anion and a metal cation selected from divalent metal cations and/or trivalent metal cations;

preferably, the divalent metal cation is selected from one or more of magnesium ion, nickel ion, cobalt ion, zinc ion and copper ion;

preferably, the trivalent metal cation is selected from one or more of aluminum ion, chromium ion, iron ion and scandium ion;

preferably, the anion is selected from one or more of carbonate, nitrate, chloride, hydroxide, sulphate, phosphate, molybdate and benzenetetraoate.

4. The production method according to claim 3, characterized in that: the hydrothermal deposition solution contains magnesium nitrate, aluminum nitrate, and sodium nitrate;

preferably, the pH of the hydrothermal deposition solution is 9-13;

preferably, the concentration of the magnesium nitrate is 12-18 g/L, and/or the concentration of the aluminum nitrate is 20-35 g/L, and/or the concentration of the sodium carbonate is 8-12 g/L.

5. The production method according to claim 3, characterized in that: the hydrothermal deposition solution contains basic nickel carbonate, aluminum nitrate and sodium carbonate;

preferably, the pH of the hydrothermal deposition solution is 9-13;

preferably, the concentration of the basic nickel carbonate is 6-12 g/L, and/or the concentration of the aluminum nitrate is 20-35 g/L, and/or the concentration of the sodium carbonate is 8-12 g/L.

6. The production method according to claim 3, characterized in that: the hydrothermal deposition solution contains zinc nitrate and sodium nitrate;

preferably, the pH of the hydrothermal deposition solution is 9-13;

preferably, the concentration of the zinc nitrate is 0.5-2 g/L, and/or the concentration of the sodium nitrate is 8-12 g/L.

7. The production method according to claims 3 to 6, characterized in that: the temperature of the impregnation is 80-150 ℃, preferably 90-130 ℃, and/or the time of the impregnation is 6-48h, preferably 12-36h or 12-24 h.

8. The production method according to claim 3, characterized in that: the hydrothermal deposition solution contains solution A and solution B, wherein the solution A contains ferric ions saturated by carbon dioxide, and the solution B is an aqueous solution saturated by carbon dioxide and adjusted to pH 9.0-11 by sodium hydroxide;

preferably, the concentration of the ferric ions is 0.08-0.12 g/L);

preferably, the pH of the solution a is 4.0 to 6.0;

preferably, the dipping temperature in the solution A is 45-55 ℃ and/or the dipping time is 30-60 min;

preferably, the dipping temperature in the liquid B is 45-55 ℃ and/or the dipping time is 30-60 min.

9. The production method according to any one of claims 1 to 8, characterized in that: the substrate material is selected from one or more of a metal, an alloy, and a metal and non-metal composite,

preferably, the base material is selected from one or more of zinc, magnesium, aluminum and alloys thereof;

preferably, the base coating material is selected from one or more of nickel, aluminum, copper, silver, cobalt, cadmium, tin, zinc, iron, chromium, titanium, lead, antimony, palladium, gold, aluminum and alloys thereof,

preferably, the addition mode of the basic coating layer is selected from one or more of electroplating, thermal spraying, diffusion coating, surfacing, hot dipping, chemical plating, physical vapor deposition, chemical vapor deposition, ion plating, vacuum evaporation, sputtering and high-energy beam surface modification.

10. A metal material produced by the production method according to any one of claims 1 to 9.