Titanium alloy polishing solution

Abstract

The invention relates to a titanium alloy polishing solution which comprises the following components in parts by mass: 3-5 parts of fluoride, 1-3 parts of a complexing agent, 8-15 parts of strong acid, 10-15 parts of an oxidizing agent, 1-2 parts of a stabilizer, 5-15 parts of a corrosion inhibitor and 45-72 parts of water. Complex of the whole materials has the advantages of being good in stability and durability, metal workpieces can be polished only through a simple container, the surfaces of the treated workpieces are smoother and finer, the light emitting rate is high, and the service life of the workpieces is prolonged. The titanium alloy immersion chemical polishing liquid does not need to be matched with polishing equipment or polishing machinery to polish metal workpieces like the existing polishing liquid in the market, can be used without professional operators, is simple to operate, basically has no requirements on the equipment, has good universality, fills the blank of titanium alloy immersion chemical polishing, and has good application prospects. And the problems of low smoothness, uneven corrosion, over-corrosion, acid mist and the like of a product polished by the existing chemical polishing solution in the market are also solved.

Description

Technical Field

[0001] The invention relates to the field of polishing liquid, in particular to a titanium alloy polishing liquid. Background Art

[0002] Titanium alloys are widely used in modern society due to their high strength, low density, strong corrosion resistance, high temperature resistance, low temperature resistance, good biocompatibility and good environmental protection. They play an irreplaceable role in important fields such as aircraft structural parts, engine parts, ship propellers, and biological stents in the aerospace field. They are also used in daily sports equipment, electronic equipment, and car brackets.

[0003] The current application status of titanium alloys shows a trend of diversification and high-end development. With the continuous advancement of science and technology and the rapid development of industry, the application field of titanium alloys will be further expanded, and its position in modern industry will become more important. As titanium alloys are increasingly widely used, the production and processing requirements for titanium alloys are also constantly increasing. The progress of each technology has directly promoted the depth and breadth of the application of titanium alloys. Among them, the polishing of titanium alloy workpieces is one of the important applications in the field of titanium alloy processing. The polishing of titanium alloys can improve the finish and increase the attractiveness, eliminate surface defects and improve the overall quality of the product, reduce the friction coefficient and extend the service life, enhance corrosion resistance, improve biocompatibility and reduce the risk of rejection, and meet the requirements of optical and electronic performance.

[0004] Commonly used titanium alloy polishing methods include mechanical polishing, electrolytic polishing, ultrasonic polishing and chemical polishing. The advantages and disadvantages of the above polishing methods are as follows: Mechanical polishing is simple to operate, and a certain degree of finish can be achieved in a short time using abrasives and polishing tools. However, it is easy to cause oxidation or deformation of the titanium alloy surface, and it is difficult to obtain a uniform polishing effect for parts with complex shapes.

[0005] Electropolishing can achieve very high surface finish and has good effect on complex shapes. However, electropolishing equipment and operation technology are demanding and the cost is high.

[0006] Ultrasonic polishing uses the energy generated by sound wave vibration to make the abrasive rub against the surface of titanium alloy, thereby achieving a full range of polishing effects. However, the polishing equipment is expensive and the polishing time is long.

[0007] Chemical polishing is to put the cleaned workpiece into the chemical polishing liquid to obtain a certain degree of finish in a short time. The polishing equipment requirements are simple. However, problems such as over-polishing corrosion and harmful gas generation are prone to occur.

[0008] The application of chemical polishing in titanium alloys is extremely rare. There are mainly problems such as low surface finish of the product after polishing, uneven corrosion, over-corrosion, and acid mist when using chemical polishing for titanium alloys. Currently, the popular polishing methods for titanium alloys on the market are mechanical polishing, electrolytic polishing, or a combination of mechanical polishing and electrolytic polishing. Since the current polishing fluids generally need to be used in conjunction with special polishing equipment (i.e., mechanical polishing) to polish workpieces, and the operation of the polishing equipment requires professional operators, which has requirements for the operators. It cannot achieve the polishing of metal workpieces with just a simple container, resulting in deficiencies such as high polishing costs, complex polishing processes, troublesome polishing, large limitations in use, and poor versatility. In addition, the formula of the current polishing fluids generally uses a single one or a combination of two or more of the traditional strong acids such as nitric acid, hydrochloric acid, and hydrofluoric acid as corrosion agents to remove impurities on the surface of the workpiece. Although it has good corrosion penetration, its volatile property will generate a large amount of acid mist under the condition of reaction heat generation. This not only seriously affects the operating environment and pollutes the environment, but also is not environmentally friendly. It also has extremely poor stability and durability. Therefore, there is an urgent hope in this field to provide a new route for the chemical polishing of titanium alloys. Summary of the Invention

[0009] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a polishing fluid for titanium alloys.

[0010] To solve the above technical problems, the present invention adopts the following technical solutions: The polishing fluid for titanium alloys includes the following components by mass parts: Fluoride: 3 - 5 parts; Complexing agent: 1 - 3 parts; Strong acid: 8 - 15 parts; Oxidizing agent: 10 - 15 parts; Stabilizer: 1 - 2 parts; Corrosion inhibitor: 5 - 15 parts; Water: 45 - 72 parts.

[0011] By adopting the above technical scheme, the compounding principle of the titanium alloy polishing liquid of the present invention is as follows: by adding a corrosion inhibitor to the components, the corrosion inhibitor can effectively prevent uneven corrosion and over-corrosion in the acid system during the reaction process through the combined action of mechanisms such as blocking the reaction, changing the electrochemical properties and ion adsorption, so that the surface of the polished titanium alloy is smoother and more delicate, so as to meet higher quality requirements; at the same time, an oxidant is added to the components to cooperate with the strong acid, and the oxidant reacts with the metal surface to form an oxide film, which can cover the original microscopic unevenness of the surface of the object, and the solubility of the strong acid makes the more convex microscopic surface oxide film dissolve first, so that the repeated action of the strong acid at the microscopic level makes the titanium alloy surface have a very good light output rate; the addition of the stabilizer can keep the oxidizability of the system highly efficient, so as to greatly improve the polishing liquid. Durability and stability; by adding fluoride to the components, the combination of strong acid and fluoride can prevent the generation of acid mist, which effectively solves the problem that chemical polishing of titanium alloys will produce a large amount of acid mist, affecting the operating environment and polluting the environment; that is, the polishing liquid obtained by compounding fluoride, chelating agent, strong acid, oxidant, stabilizer, corrosion inhibitor and water does not generate acid mist during use, has little foam and no overflow risk, and has high durability. It can realize the polishing of metal workpieces with only a simple container, does not require the aid of polishing machinery or polishing equipment, is simple to use, has basically no requirements for equipment and operators, has good universality, and effectively solves the main problems of chemical polishing currently available on the market in the treatment of titanium alloys, such as low finish of polished products, uneven corrosion, over-corrosion, acid mist, poor stability and poor durability.

[0012] Preferably, the fluoride comprises one or a mixture of sodium fluoride and potassium fluoride.

[0013] By adopting the above technical solution, the addition of fluoride can provide fluoride ions to make the polishing liquid more permeable and soluble, and provide extremely strong dissolving ability for insoluble metal oxide scales and impurities.

[0014] Preferably, the complexing agent is citric acid.

[0015] By adopting the above-mentioned technical scheme, the addition of chelating agents can form complexes with the oxides on the surface of titanium alloys. These complexes play an important role in the chemical polishing process. By combining with the metal ions in the oxide layer, they become soluble in the solution, allowing the polishing reaction to proceed smoothly, which helps to remove the oxide layer, pollutants and other impurities on the surface of titanium alloys.

[0016] Preferably, the strong acid comprises one or a mixture of sulfuric acid and trifluoromethanesulfonic acid.

[0017] By adopting the above technical scheme, the addition of non-volatile strong acid can not only react with oxides, pollutants and other impurities on the surface of titanium alloy, but also dissolve the uneven parts first, so as to improve the roughness of the surface of titanium alloy and enhance the glossiness of the surface of titanium alloy, making the surface of titanium alloy smoother. The combination of strong acid and fluoride can prevent the generation of acid mist, which effectively solves the problem that chemical polishing of titanium alloy will generate a large amount of acid mist, which affects the operating environment and pollutes the environment.

[0018] Preferably, the oxidant is hydrogen peroxide.

[0019] By adopting the above technical scheme, the oxidant and the strong acid are combined to react with the metal surface to form an oxide film. This oxide film can cover the original microscopic unevenness of the surface of the object. Then the solubility of the strong acid causes the more convex microscopic surface oxide film to dissolve first. The repeated action of the strong acid and the microscopic surface makes the titanium alloy surface smoother and brighter, so as to solve the current problems of chemical polishing of titanium alloy, such as low finish of the polished product, uneven corrosion and over-corrosion.

[0020] Preferably, the stabilizer includes one or a mixture of two of sodium stannate and glycine.

[0021] By adopting the above-mentioned technical scheme, the addition of the stabilizer can not only effectively stabilize the easy decomposition property of the oxidant, but also effectively prevent the generation of acidic gas, thereby improving the stability and durability of the polishing liquid quality, thereby solving the problem that the polishing liquid on the market has extremely poor stability and durability and causes great damage to the environment.

[0022] Preferably, the corrosion inhibitor includes one or a mixture of two or more of polyethylene glycol, thiourea and ethylenediaminetetramethylenephosphonic acid.

[0023] By adopting the above technical solution, during the polishing process, the acid will react chemically with the metal, which can easily cause excessive corrosion of the metal. This product adds a corrosion inhibitor, which works together through mechanisms such as blocking the reaction, changing the electrochemical properties and ion adsorption to prevent the acid from over-corroding the metal, making the product shine more evenly. This effectively solves the problems of low finish, uneven corrosion and excessive corrosion of titanium alloys currently on the market after chemical polishing.

[0024] Preferably, the present invention also provides a method for preparing a titanium alloy polishing liquid: Step (1): adding the aforementioned number of complexing agents into a container containing the aforementioned number of water to dissolve the complexing agent, and stirring until the complexing agent is completely dissolved.

[0025] Step (2): Add the aforementioned amounts of strong acid and fluoride into a container respectively, and stir until the strong acid and fluoride are completely dissolved.

[0026] Step (3): Add the aforementioned portions of corrosion inhibitor, stabilizer and oxidant into a container respectively, and stir until the corrosion inhibitor, stabilizer and oxidant are completely dissolved to prepare a titanium alloy polishing liquid.

[0027] The titanium alloy polishing liquid prepared by the above-mentioned components and preparation method produces less foam and no acid mist when polishing titanium alloy, is easy to operate, and does not cause over-corrosion and uneven corrosion. The polished titanium alloy surface has excellent polishing finish.

[0028] Compared with the existing polishing liquid, the beneficial effects of the present invention are: 1. The present invention adds an oxidant to the components, and the oxidant provides a very good light output rate; at the same time, it adds a corrosion inhibitor to the components, and the corrosion inhibitor can very effectively prevent uneven corrosion and over-corrosion in the acid system during the reaction process, so that the surface of the polished metal workpiece is smoother and more delicate to meet higher quality requirements. The product washed with the titanium alloy polishing liquid made by the components and preparation method of the present invention has high smoothness and no problems of over-corrosion and uneven corrosion.

[0029] 2. By adding strong acid and fluoride to the components, the combination of strong acid and fluoride can make the present invention produce no acid mist during use, less foam, no overflow risk, high durability, so that it can effectively solve the problem that the polishing liquid components on the market generally use one or more of the traditional strong acids such as nitric acid, hydrochloric acid and hydrofluoric acid as the etchant, which will produce a large amount of acid mist in the case of heat generation due to its volatile characteristics, affecting the operating environment and polluting the environment. At the same time, by adding a stabilizer to the components, the stabilizer can keep the oxidizability of the entire system highly efficient, so as to greatly improve the durability and stability of the polishing liquid.

[0030] 3. The present invention is a chemical titanium alloy polishing liquid containing fluoride, chelating agent, strong acid, oxidant, stabilizer, corrosion inhibitor and water. The titanium alloy polishing liquid produced by the formula and preparation method of the present invention can polish metal workpieces with only a simple container. It does not need to be used in conjunction with polishing equipment or polishing mechanism like the polishing liquid on the market to polish the surface of the metal workpiece. It can be used without professional operators, is simple to operate, has basically no requirements for equipment, and has good universality. It not only fills the gap in immersion chemical polishing of titanium alloys, but also effectively solves the main problems of existing chemical polishing, such as low smoothness of polished products, uneven corrosion, over-corrosion and generation of acid mist. DETAILED DESCRIPTION

[0031] The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention. Example 1

[0032] This embodiment discloses a titanium alloy polishing liquid, which comprises the following components in parts by mass: Fluoride: 3 parts; Complexing agent: 2 parts; Strong acid: 8 parts; Oxidant: 10 parts; Stabilizer: 2 parts; Corrosion inhibitor: 15 parts; Water: 60 parts.

[0033] The fluoride is a mixture of sodium fluoride and potassium fluoride, and the weight ratio of sodium fluoride to potassium fluoride is 1:1.

[0034] Wherein, the complexing agent is citric acid.

[0035] The strong acid is a mixture of sulfuric acid and trifluoromethanesulfonic acid, and the weight ratio of sulfuric acid to trifluoromethanesulfonic acid is 7:1.

[0036] Wherein, the oxidant is hydrogen peroxide, and the stabilizer is sodium stannate.

[0037] The corrosion inhibitor is a mixture of polyethylene glycol, thiourea and ethylenediaminetetramethylenephosphonic acid, and the weight ratio of polyethylene glycol, thiourea and ethylenediaminetetramethylenephosphonic acid is 3:1:1.

[0038] The preparation method of the titanium alloy polishing liquid comprises: step (1): adding the above-mentioned number of complexing agents into a container containing the above-mentioned number of water to dissolve the complexing agents, and stirring until the complexing agents are completely dissolved.

[0039] Step (2): Add the above-mentioned amounts of strong acid and fluoride into a container respectively, and stir until the strong acid and fluoride are completely dissolved.

[0040] Step (3): Add the above-mentioned amounts of corrosion inhibitor, stabilizer and oxidant into a container respectively, and stir until the corrosion inhibitor, stabilizer and oxidant are completely dissolved to prepare a titanium alloy polishing liquid. Example 2

[0041] This embodiment discloses a titanium alloy polishing liquid, which comprises the following components in parts by mass: Fluoride: 3 parts; Complexing agent: 3 parts; Strong acid: 10 parts; Oxidant: 12 parts; Stabilizer: 2 parts; Corrosion inhibitor: 11 parts; Water: 59 parts.

[0042] Wherein, the fluoride is sodium fluoride, and the complexing agent is citric acid.

[0043] Wherein, the strong acid is sulfuric acid.

[0044] Wherein, the oxidant is hydrogen peroxide, and the stabilizer is glycine.

[0045] The corrosion inhibitor is a mixture of polyethylene glycol and ethylenediaminetetramethylenephosphonic acid, and the weight ratio of polyethylene glycol to ethylenediaminetetramethylenephosphonic acid is 8:1.

[0046] The preparation method of the titanium alloy polishing liquid comprises: step (1): adding the above-mentioned number of complexing agents into a container containing the above-mentioned number of water to dissolve the complexing agents, and stirring until the complexing agents are completely dissolved.

[0047] Step (2): Add the above-mentioned amounts of strong acid and fluoride into a container respectively, and stir until the strong acid and fluoride are completely dissolved.

[0048] Step (3): Add the above-mentioned amounts of corrosion inhibitor, stabilizer and oxidant into a container respectively, and stir until the corrosion inhibitor, stabilizer and oxidant are completely dissolved to prepare a titanium alloy polishing liquid. Example 3

[0049] This embodiment discloses a titanium alloy polishing liquid, which comprises the following components in parts by mass: Fluoride: 4 parts; Complexing agent: 3 parts; Strong acid: 12 parts; Oxidant: 13 parts; Stabilizer: 1 part; Corrosion inhibitor: 10 parts; Water: 57 parts.

[0050] Wherein, the fluoride is potassium fluoride, and the complexing agent is citric acid.

[0051] Wherein, the strong acid is trifluoromethanesulfonic acid.

[0052] The oxidant is hydrogen peroxide, the stabilizer is a mixture of sodium stannate and glycine, and the weight ratio of sodium stannate to glycine is 1:1.

[0053] The corrosion inhibitor is a mixture of polyethylene glycol and ethylenediaminetetramethylenephosphonic acid, and the weight ratio of polyethylene glycol to ethylenediaminetetramethylenephosphonic acid is 8:1.

[0054] The preparation method of the titanium alloy polishing liquid comprises: step (1): adding the above-mentioned number of complexing agents into a container containing the above-mentioned number of water to dissolve the complexing agents, and stirring until the complexing agents are completely dissolved.

[0055] Step (2): Add the above-mentioned amounts of strong acid and fluoride into a container respectively, and stir until the strong acid and fluoride are completely dissolved.

[0056] Step (3): Add the above-mentioned amounts of corrosion inhibitor, stabilizer and oxidant into a container respectively, and stir until the corrosion inhibitor, stabilizer and oxidant are completely dissolved to prepare a titanium alloy polishing liquid. Example 4

[0057] This embodiment discloses a titanium alloy polishing liquid, which comprises the following components in parts by mass: Fluoride: 5 parts; Complexing agent: 3 parts; Strong acid: 15 parts; Oxidant: 15 parts; Stabilizer: 2 parts; Corrosion inhibitor: 15 parts; Water: 45 parts.

[0058] The fluoride is a mixture of sodium fluoride and potassium fluoride, and the weight ratio of sodium fluoride to potassium fluoride is 1:1.

[0059] Wherein, the complexing agent is citric acid.

[0060] The strong acid is a mixture of sulfuric acid and trifluoromethanesulfonic acid, and the weight ratio of sulfuric acid to trifluoromethanesulfonic acid is 14:1.

[0061] The oxidant is hydrogen peroxide, the stabilizer is a mixture of sodium stannate and glycine, and the weight ratio of sodium stannate to glycine is 10:1.

[0062] The corrosion inhibitor is a mixture of polyethylene glycol, thiourea and ethylenediaminetetramethylenephosphonic acid, and the weight ratio of polyethylene glycol, thiourea and ethylenediaminetetramethylenephosphonic acid is 13:1:1.

[0063] The preparation method of the titanium alloy polishing liquid comprises: step (1): adding the above-mentioned number of complexing agents into a container containing the above-mentioned number of water to dissolve the complexing agents, and stirring until the complexing agents are completely dissolved.

[0064] Step (2): Add the above-mentioned amounts of strong acid and fluoride into a container respectively, and stir until the strong acid and fluoride are completely dissolved.

[0065] Step (3): Add the above-mentioned amounts of corrosion inhibitor, stabilizer and oxidant into a container respectively, and stir until the corrosion inhibitor, stabilizer and oxidant are completely dissolved to prepare a titanium alloy polishing liquid. Example 5

[0066] This embodiment discloses a polishing liquid, which comprises the following components in parts by mass: Complexing agent: 3 parts; Corrosive agent: 15 parts; Oxidant: 15 parts; Stabilizer: 2 parts; Corrosion inhibitor: 15 parts; Water: 50 parts.

[0067] Wherein, the complexing agent is citric acid.

[0068] The etchant is a mixture of hydrofluoric acid and nitric acid, and the weight ratio of the hydrofluoric acid to the nitric acid is 1:1.

[0069] The oxidant is hydrogen peroxide, the stabilizer is a mixture of sodium stannate and glycine, and the weight ratio of sodium stannate to glycine is 10:1.

[0070] The corrosion inhibitor is a mixture of thiourea and ethylenediaminetetramethylenephosphonic acid, and the weight ratio of thiourea to ethylenediaminetetramethylenephosphonic acid is 1:1.

[0071] The preparation method of the polishing liquid is as follows: Step (1): adding the above-mentioned number of complexing agents into a container containing the above-mentioned number of water to dissolve the complexing agents, and stirring until the complexing agents are completely dissolved.

[0072] Step (2): Add the above-mentioned amount of corrosive agent into a container and stir until the corrosive agent is completely dissolved.

[0073] Step (3): Add the above-mentioned amounts of corrosion inhibitor, stabilizer and oxidant into a container respectively, and stir until the corrosion inhibitor, stabilizer and oxidant are completely dissolved to prepare a titanium alloy polishing liquid.

[0074] The method for polishing titanium alloy workpieces is as follows: first, five titanium alloy workpieces with the same glossiness to be polished are subjected to neutral degreasing pretreatment, water washing, and drying, and then the mass at this time is recorded as m. 1 Then, the five titanium alloy workpieces are directly put into the polishing liquid prepared by Example 1-5 and immersed in polishing for 2 minutes. After the time is up, the five titanium alloy workpieces are taken out and washed and dried under the same conditions respectively, and then the mass at this time is recorded as m 2 The results of various measurements are shown in the following table:

[0075] The mass parts in Examples 1-4 of the present invention are all within the required range of the titanium alloy polishing liquid disclosed in the present invention. From the data in the above table, it can be seen that the appearance of the titanium alloy workpieces treated with the titanium alloy polishing liquid prepared in Examples 1-4 of the present invention is uniform and smooth, among which the titanium alloy workpiece of Example 4 has the highest gloss (light output rate) after chemical polishing; while Example 5 (the polishing liquid currently on the market) does not contain fluoride, and it uses traditional hydrofluoric acid and nitric acid as corrosive agents, and its corrosion degree after polishing is the highest, and its light output rate is the lowest. This shows that the titanium alloy polishing liquid made from the above ingredients and preparation method produces less foam and no acid mist when polishing titanium alloy, and there will be no over-corrosion and uneven corrosion. The titanium alloy workpiece has excellent surface polishing finish, and the corrosion resistance and durability are significantly improved. It also achieves the goal of polishing the metal workpiece with only a simple container. It does not need to be used in conjunction with special polishing equipment, is simple to operate, has basically no requirements for equipment, and has good universality. It overcomes the problems of low polishing product finish, uneven corrosion, over-corrosion and acid mist generation in the current chemical polishing liquid on the market, and fills the gap in immersion chemical polishing of titanium alloys.

[0076] The present invention is not limited to the above-mentioned optimal implementation mode. Any other products identical or similar to the present invention obtained by anyone under the inspiration of the present invention shall fall within the protection scope of the present invention.

Claims

1. A titanium alloy polishing liquid, characterized in that: The titanium alloy polishing liquid comprises the following components in parts by mass: Fluoride: 3-5 parts; Complexing agent: 1-3 parts; Strong acid: 8-15 parts; Oxidant: 10-15 parts; Stabilizer: 1-2 parts; Corrosion inhibitor: 5-15 parts; Water: 45-72 parts; The strong acid includes one of sulfuric acid and trifluoromethanesulfonic acid or a mixture of the two.

2. The titanium alloy polishing liquid according to claim 1, characterized in that: The fluoride includes one of sodium fluoride and potassium fluoride or a mixture of the two.

3. The titanium alloy polishing liquid according to claim 1, characterized in that: The complexing agent is citric acid.

4. The titanium alloy polishing liquid according to claim 1, characterized in that: The oxidant is hydrogen peroxide.

5. The titanium alloy polishing liquid according to claim 1, characterized in that: The stabilizer includes one or a mixture of sodium stannate and glycine.

6. The titanium alloy polishing liquid according to claim 1, characterized in that: The corrosion inhibitor comprises one or a mixture of two or more of polyethylene glycol, thiourea and ethylenediaminetetramethylenephosphonic acid.

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