Environmentally friendly titanium alloy polishing liquid and polishing method thereof

Abstract

The present invention relates to the technical field of metal polishing, and specifically provides an environmentally friendly titanium alloy polishing liquid and a polishing method thereof, wherein the environmentally friendly titanium alloy polishing liquid is composed of the following components: 77-87% by mass of plant extracts, 2-6% by mass of 1g natural sponge fragments, 2-4% by mass of 3g bamboo pieces, and pure water to make up the balance. The core idea of ​​the present invention is to use milder plant-derived acids such as citric acid, and to achieve chemical polishing by ultrasonic assistance, increasing the reaction temperature, and extending the reaction time while being environmentally friendly. At the same time, extracts of bayberry leaves and papaya fruits are used to take into account both corrosion inhibition and stable reaction environment, and finally take into account lower surface roughness, higher glossiness, lower weight loss, and lower water pollution.

Description

Technical Field

[0001] The invention relates to the technical field of metal polishing, and in particular to an environmentally friendly titanium alloy polishing liquid and a polishing method thereof. Background Art

[0002] Titanium alloys are generally in need of polishing treatment because they are damaged and contaminated during processing and transportation, resulting in scale, rust, oil stains, and sandblasting residues. Polishing fluid is a special solution for micro-finishing the surface of titanium alloys, which can improve the surface quality of titanium alloy workpieces. Existing polishing fluids mostly use the dissolution, mechanical stripping, and reduction effects of inorganic acids to improve the surface properties of titanium alloys. However, inorganic acids such as hydrofluoric acid and nitric acid not only volatilize and are harmful to the human body during use, but also aluminum-iron-titanium and other abrasives are polluted by heavy metals during post-treatment. Oxidants such as nitrates are directly discharged after use, which also causes great eutrophication pollution to water bodies. In order to avoid damage to the water ecology, the cost of post-treatment such as ion exchange has to be increased, which hinders the promotion of titanium alloy technology.

[0003] Therefore, it is necessary to develop a low-toxic, environmentally friendly titanium alloy polishing liquid and a polishing method thereof, which can achieve better surface roughness improvement and gloss improvement effects while using environmentally friendly green raw materials, and have lower weight loss and water pollution. Summary of the invention

[0004] In order to solve the above problems, the present invention aims to provide an environmentally friendly titanium alloy polishing liquid and a polishing method thereof.

[0005] In one aspect, the present invention provides an environmentally friendly titanium alloy polishing liquid, wherein the environmentally friendly titanium alloy polishing liquid is composed of the following components:

[0006] 77-87% by weight of plant extract, 2-6% by weight of 1g natural sponge fragments, 2-4% by weight of 3g bamboo chips and the balance of pure water;

[0007] The preparation method of the plant extract:

[0008] Take 82-90% of fresh lemon fruit, 5-8% of bayberry leaves and the rest of papaya fruit, cut into 1 cm 3 The pieces are put into a flash extractor, and one times the mass of 85% ethanol aqueous solution is added. The extraction speed is 4000r / min and then filtered through a 100-mesh filter to obtain a coarse filtration extract; the coarse filtration extract is reduced pressure and concentrated at 45-53°C and a vacuum degree of 800mbar to 0.2 times the mass of the coarse filtration extract to obtain the plant extract.

[0009] Furthermore, the mass fraction of the plant extract is 83%.

[0010] Furthermore, the mass fraction of the natural sponge fragments is 4%.

[0011] Furthermore, the mass fraction of the bamboo chips is 3%.

[0012] Furthermore, the mass fraction of the lemon fruit is 88%.

[0013] Furthermore, the mass fraction of the bayberry leaves is 6%.

[0014] Furthermore, the crude filtration extract is concentrated under reduced pressure at 51° C. and a vacuum degree of 800 mbar to 0.2 times the mass of the crude filtration extract.

[0015] On the other hand, the present invention provides a polishing method of the environmentally friendly titanium alloy polishing liquid as described above, wherein the polishing method of the environmentally friendly titanium alloy polishing liquid is:

[0016] Step 1: A titanium alloy plate with a surface roughness of 300 nm and a surface gloss of 350 GU after being polished with 10×5×0.5 cm sandpaper of TC4 grade is washed with pure water, blown dry, and then placed in a PP pickling tank, and the environmentally friendly titanium alloy polishing liquid is poured into the PP pickling tank to immerse the titanium alloy plate and stir evenly;

[0017] Step 2: Heat the temperature of the environmentally friendly titanium alloy polishing liquid to 55-62°C, replace the environmentally friendly titanium alloy polishing liquid every 1 hour under 40KHz, 2500W ultrasonic action, after cleaning for 3 hours, take out the titanium alloy plate, wash it twice with pure water, and then dry it at 60°C for 1 hour to complete polishing.

[0018] Furthermore, in the step 2, the temperature of the environmentally friendly titanium alloy polishing liquid is heated to 59°C.

[0019] The present invention can bring the following beneficial effects:

[0020] Generally speaking, higher temperatures can increase the number and activity of hydrogen ions ionized by the acid solution, thereby increasing the rate of the redox reaction and increasing the solubility of titanium ions in the acid solution, thereby macroscopically improving the chemical polishing effect; however, the commonly used chemical polishing solutions for titanium alloys, hydrofluoric acid and nitric acid, do not use higher process temperatures due to their violent reactions, active properties and high volatility. For example, Wang Jianchao et al. adopted a pickling process of 15~35°C and 1~2min in "Pickling Process for TC4 Titanium Alloy Before Welding", and used corrosion inhibitors to avoid excessive corrosion; the present invention creatively uses milder plant-derived acids such as citric acid, and while being environmentally friendly, achieves chemical polishing through ultrasonic assistance, increased reaction temperature and prolonged reaction time, while using bayberry leaves and papaya fruits to take into account both corrosion inhibition and a stable reaction environment.

[0021] J.Mol. Liq. found in "Walnut shell extract as a sustainable, efficient and green corrosion inhibitor for low-carbon steel in 3.5 wt% NaCl solution: detailed atomic-level calculation and electrochemical study" that coumaric acid, ferulic acid, syringic acid, vanillic acid, juglone and myricetin attached to the surface of iron metal help prevent corrosion and can form a protective layer over a long period of time; the present invention is boldly designed to extract myricetin from bayberry leaves to achieve mild corrosion inhibition of titanium alloy without hindering polishing, and the feasibility has been verified experimentally.

[0022] The core idea of ​​the present invention is to utilize milder plant-derived acids such as citric acid, and realize chemical polishing by ultrasonic assistance, increasing the reaction temperature and prolonging the reaction time while being environmentally friendly. At the same time, extracts of bayberry leaves and papaya fruits are used to take into account both corrosion inhibition and stabilizing the reaction environment, ultimately achieving lower surface roughness, higher gloss, lower weight loss and lower water pollution.

[0023] The present invention uses citric acid and other organic acid substances extracted from lemon fruits to corrode and remove the oxide layer on the surface of the titanium alloy and reduce the roughness. At the same time, the oxidizing property of the organic acid substances themselves can form a passivation oxide film to avoid excessive corrosion. The phenolic compounds with antioxidant properties extracted from papaya fruits control the oxidation rate of organic acids while protecting the activity of organic acids extracted from lemon fruits. Furthermore, biopolysaccharides such as cellulose in the plant extract of the present invention can play the role of a dispersant and improve the stability of the polishing liquid system.

[0024] The natural sponge fragments and bamboo pieces of the present invention have a hardness of one low and one high. With the frequency-converting ultrasonic wave-assisted cleaning of the present invention, while the natural sponge fragments peel off and take away the oxide layer damaged by the organic acid, the bamboo pieces polish the surface of the titanium alloy, exposing a larger area of ​​protrusions through more friction, making the surface of the titanium alloy smoother.

[0025] The component ratio of the plant extract, natural sponge fragments and bamboo pieces of the present invention is unique, and the corrosion effect is poor when the plant extract is less, and the mechanical polishing effect is poor when the natural sponge fragments and bamboo pieces are less; the component ratio of the lemon fruit, bayberry leaf and papaya fruit of the present invention is unique, and the oxidation corrosion effect is poor when the lemon fruit is less, and the system stability is poor when the bayberry leaf and papaya fruit are less; the temperature of the reduced pressure concentration of the present invention protects the activity of organic acids and phenols while removing part of the water and volatile substances; the use temperature of the environmentally friendly titanium alloy polishing liquid of the present invention improves the corrosion and polishing effects while avoiding the decrease of the biological activity of the polishing liquid or the instability of the system to produce agglomeration precipitation.

[0026] Under the above cooperation, the oxide film on the surface of titanium alloy is continuously dissolved, and the passivation oxide film is continuously formed. The microscopic raised parts of the surface are dissolved first, and the dissolution rate is greater than the dissolution rate of the concave parts; and the dissolution of the oxide film and the formation of the oxide film are always carried out at the same time, but the rates are different, achieving the dual effects of chemical corrosion and mechanical grinding, and as a result, a better surface roughness improvement effect and surface peeling effect are achieved while using environmentally friendly materials. DETAILED DESCRIPTION

[0027] In order to more clearly explain the overall concept of the present invention, the overall scheme of the present invention is described in detail in the form of embodiments below; in the following description, a large number of specific details are given to provide a more thorough understanding of the present invention; however, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details; in other examples, in order to avoid confusion with the present invention, some technical features known in the art are not described.

[0028] The model of the flash extractor was JHBE-50T; the pH value of the lemon fruit was measured to be 2.4, the ratio of acidic substances was citric acid: malic acid: tartaric acid = 19:3:1, and the ORAC value was measured to be 9046 micromoles; the bayberry leaves were purchased from the 8-year-old bayberry leaves of Jiujiang Chaiyuan Agricultural and Forestry Development Co., Ltd., and the myricetin content was measured to be 92 mg / g; the papaya fruit was purchased from Zhangzhou Shizhika Agricultural Development Co., Ltd., and the total polyphenol content was 47 mg / g, and the total flavonoids content was 78 mg / g; the natural sponge fragments were purchased from Sumikuma Trading Company, Yangxi Street, Jiande City, and cut into 1g specifications by themselves; the bamboo pieces were purchased from Wanzhu Bamboo Products (Anhui) Co., Ltd., the variety was nanmu, and the hardness was measured to be 3.4 Mohs hardness; the SR2000 roughness meter was purchased from Changzhou Jonah Electromechanical Technology Co., Ltd.; the CS-380 gloss meter was purchased from Caipu Technology Co., Ltd. Unless otherwise specified, all raw material components in the following examples can be purchased through commercial channels, the experimental instruments used are conventional laboratory experimental instruments, and the performance testing methods are the testing methods known in the art.

[0029] The preferred implementation is as follows:

[0030] Embodiment 1:

[0031] Environmentally friendly titanium alloy polishing fluid with the following components:

[0032] 83% by weight of plant extract, 4% by weight of 1g natural sponge fragments, 3% by weight of 3g bamboo chips and the balance of pure water;

[0033] The plant extract was prepared by the following method:

[0034] Take 88% of fresh lemon fruit, 6% of bayberry leaves and the rest of papaya fruit, cut into 1 cm 3 The pieces are put into a flash extractor, and one times the mass of 85% ethanol aqueous solution is added. The extraction speed is 4000 r / min for 30 seconds, and then filtered through a 100-mesh filter to obtain a coarse filtration extract; the coarse filtration extract is reduced pressure and concentrated to 0.2 times the mass of the coarse filtration extract at 51° C. and a vacuum degree of 800 mbar to obtain the plant extract;

[0035] Polishing is done by:

[0036] Step 1: A titanium alloy plate with a surface roughness of 300 nm and a surface gloss of 350 GU after being polished with 10×5×0.5 cm sandpaper of TC4 grade is washed with pure water, blown dry, and then placed in a PP pickling tank, and the environmentally friendly titanium alloy polishing liquid is poured into the PP pickling tank to immerse the titanium alloy plate and stir evenly;

[0037] Step 2: Heat the temperature of the environmentally friendly titanium alloy polishing liquid to 59°C, replace the environmentally friendly titanium alloy polishing liquid every 1 hour under 40KHz, 2500W ultrasonic action, after cleaning for 3 hours, take out the titanium alloy plate, wash it twice with pure water, and then dry it at 60°C for 1 hour to complete polishing.

[0038] Embodiment 2-15:

[0039] The only difference between Example 2 and Example 1 is that the mass fraction of the plant extract is 77%;

[0040] The only difference between Example 3 and Example 1 is that the mass fraction of the plant extract is 87%;

[0041] The only difference between Example 4 and Example 1 is that the mass fraction of the natural sponge fragments is 2%;

[0042] The only difference between Example 5 and Example 1 is that the mass fraction of the natural sponge fragments is 6%;

[0043] The only difference between Example 6 and Example 1 is that the mass fraction of the bamboo chips is 2%;

[0044] The only difference between Example 7 and Example 1 is that the mass fraction of the bamboo chips is 4%;

[0045] The only difference between Example 8 and Example 1 is that the mass fraction of lemon fruit is 82%;

[0046] The only difference between Example 9 and Example 1 is that the mass fraction of lemon fruit is 90%;

[0047] The only difference between Example 10 and Example 1 is that the mass fraction of bayberry leaves is 5%;

[0048] The only difference between Example 11 and Example 1 is that the mass fraction of bayberry leaves is 8%;

[0049] The difference between Example 12 and Example 1 is that the crude filtrate extract is concentrated under reduced pressure at 45° C. and a vacuum degree of 800 mbar to 0.2 times the mass of the crude filtrate extract;

[0050] The difference between Example 13 and Example 1 is that the crude filtrate extract is concentrated under reduced pressure at 53° C. and a vacuum degree of 800 mbar to 0.2 times the mass of the crude filtrate extract;

[0051] The only difference between Example 14 and Example 1 is that the temperature of the environmentally friendly titanium alloy polishing liquid in step 2 is heated to 55° C.;

[0052] The only difference between Example 15 and Example 1 is that the temperature of the environmentally friendly titanium alloy polishing liquid in step 2 is heated to 62° C.;

[0053] Comparative Examples 1-17:

[0054] The difference between Comparative Example 1 and Example 1 is that the mass fraction of the plant extract is 70%;

[0055] The only difference between Comparative Example 2 and Example 1 is that the mass fraction of the plant extract is 90%;

[0056] The only difference between Comparative Example 3 and Example 1 is that the mass fraction of natural sponge fragments is 0%;

[0057] The only difference between Comparative Example 4 and Example 1 is that the mass fraction of natural sponge fragments is 10%;

[0058] The difference between Comparative Example 5 and Example 1 is that the mass fraction of bamboo chips is 0%;

[0059] The only difference between Comparative Example 6 and Example 1 is that the mass fraction of the bamboo chips is 6%;

[0060] The only difference between Comparative Example 7 and Example 1 is that the mass fraction of lemon fruit is 70%;

[0061] The only difference between Comparative Example 8 and Example 1 is that the mass fraction of lemon fruit is 94%;

[0062] The difference between Comparative Example 9 and Example 1 is that the mass fraction of bayberry leaves is 0%;

[0063] The difference between Comparative Example 10 and Example 1 is that the mass fraction of bayberry leaves is 12%;

[0064] The difference between Comparative Example 11 and Example 1 is that the crude filtrate extract is concentrated under reduced pressure at 40° C. and a vacuum degree of 800 mbar to 0.2 times the mass of the crude filtrate extract;

[0065] The difference between Comparative Example 12 and Example 1 is that the crude filtrate extract is concentrated under reduced pressure at 60° C. and a vacuum degree of 800 mbar to 0.2 times the mass of the crude filtrate extract;

[0066] The difference between Comparative Example 13 and Example 1 is that the temperature of the environmentally friendly titanium alloy polishing liquid in step 2 is heated to 45° C.;

[0067] The difference between Comparative Example 14 and Example 1 is that the temperature of the environmentally friendly titanium alloy polishing liquid in step 2 is heated to 70° C.;

[0068] The difference between Comparative Example 15 and Example 1 is only that the polishing method does not have ultrasonic action;

[0069] The difference between Comparative Example 16 and Example 1 is that the plant extract uses a commercially available aqua regia polishing liquid of equal mass, whose components are HCl 60-70 g / L, HNO3 100-200 g / L, HF 70-90 g / L, the polishing temperature is reduced to 35°C, and the polishing time is 5 min;

[0070] The only difference between Comparative Example 17 and Example 1 is that the polishing liquid uses an equal mass of commercially available aqua regia polishing liquid, whose components are HCl 60~70g / L, HNO3 100~200g / L, HF 70~90g / L, the polishing temperature is reduced to 35°C, and the polishing time is 5min.

[0071] Blank control group: The blank control group differs from Example 1 only in that an environmentally friendly titanium alloy polishing liquid is replaced with pure water of equal mass.

[0072] Take the polished titanium alloy plates of each example, mark a 10×5 cm surface of each titanium alloy plate as surface A, and perform the following tests:

[0073] Surface roughness improvement effect test:

[0074] The surface roughness Ra was measured using an SR2000 roughness meter. The A surface of the titanium alloy plate was placed vertically upward on the inclination adjustment table and adjusted to a horizontal level. The rectangular coordinate measurement method was used to measure the coordinate points of the surface contour of the measured part through the X-axis and Z1-axis sensors. The coordinate point data measured by the sensor was transmitted to the upper PC through the electrical components. The software performed mathematical operations on the collected original coordinate data, marked the required engineering measurement items, and viewed the output roughness results on the screen. The test results are shown in Table 1. The unit of the test results is nm, and the integer digits are retained.

[0075] Surface gloss improvement effect test:

[0076] The surface gloss was measured using a CS-380 gloss meter. The A surface of the titanium alloy plate was placed vertically upward on a horizontal plane, and the measuring angle was set to 60°. After calibration, the measuring aperture of the instrument was placed close to the center of the A surface to be measured, and "measurement" was clicked. After waiting for 2 seconds, the screen numbers were read. The test results are shown in Table 1. The unit of the test results is GU, and the integer digits are retained.

[0077] Weight loss test:

[0078] The weight difference of the titanium alloy plate before and after polishing was weighed and calculated. The results are shown in Table 1. The unit of the test result is mg, and the integer significant figures are retained.

[0079] Water pollution test:

[0080] The polishing wastewater of each example was discharged into a separate 15m 2 The fish in the pond were 1m deep and contained 1kg of green dust algae. The initial chlorophyll a concentration in the water was 10.3μg / L. A week later, water samples were taken and the mass concentration of chlorophyll a was detected and calculated according to the method of "Determination of Chlorophyll a (B)" in Chapter 1 of Part 5 of the fourth edition of "Water and Wastewater Monitoring and Analysis Methods". The results are shown in Table 1. The unit of the test result is μg / L, and one significant figure after the decimal point is retained.

[0081] Table 1: Surface roughness improvement effect test, surface gloss improvement effect, weight loss and water pollution test of each example:

[0082]

[0083] It can be seen from the data in Table 1 that, compared with other examples except the blank control group, the embodiments of the present invention, especially the environmentally friendly titanium alloy polishing liquid and the polishing method of Example 1 of the present invention, have lower surface roughness Ra, higher surface gloss, lower weight loss and lower water chlorophyll a concentration; Obviously, the embodiments of the present invention, especially the environmentally friendly titanium alloy polishing liquid and the polishing method of Example 1 of the present invention, have better surface roughness improvement effect, surface gloss improvement effect, small titanium alloy plate loss and low water pollution.

[0084] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An environmentally friendly titanium alloy polishing liquid, characterized in that: The environmentally friendly titanium alloy polishing liquid is composed of the following components: 77-87% by weight of plant extract, 2-6% by weight of 1g natural sponge fragments, 2-4% by weight of 3g bamboo chips and the balance of pure water; The preparation method of the plant extract: Take 82-90% of fresh lemon fruit, 5-8% of bayberry leaves and the rest of papaya fruit, cut into 1 cm 3 The pieces are put into a flash extractor, and one times the mass of 85% ethanol aqueous solution is added. The extraction speed is 4000r / min and then filtered through a 100-mesh filter to obtain a coarse filtration extract; the coarse filtration extract is reduced pressure and concentrated at 45-53°C and a vacuum degree of 800mbar to 0.2 times the mass of the coarse filtration extract to obtain the plant extract.

2. The environmentally friendly titanium alloy polishing liquid according to claim 1, characterized in that: The mass fraction of the plant extract is 83%.

3. The environmentally friendly titanium alloy polishing liquid according to claim 1, characterized in that: The mass fraction of the natural sponge fragments is 4%.

4. The environmentally friendly titanium alloy polishing liquid according to claim 1, characterized in that: The mass fraction of the bamboo chips is 3%.

5. The environmentally friendly titanium alloy polishing liquid according to claim 1, characterized in that: The mass fraction of the lemon fruit is 88%.

6. The environmentally friendly titanium alloy polishing liquid according to claim 1, characterized in that: The mass fraction of the bayberry leaves is 6%.

7. The environmentally friendly titanium alloy polishing liquid according to claim 1, characterized in that: The crude filtrate extract was concentrated under reduced pressure at 51° C. and a vacuum degree of 800 mbar to 0.2 times the mass of the crude filtrate extract.

8. A polishing method for an environmentally friendly titanium alloy polishing liquid as claimed in any one of claims 1 to 7, characterized in that: The polishing method of the environmentally friendly titanium alloy polishing liquid is: Step 1: A titanium alloy plate with a surface roughness of 300 nm and a surface gloss of 350 GU after being polished with 10×5×0.5 cm sandpaper of TC4 grade is washed with pure water, blown dry, and then placed in a PP pickling tank, and the environmentally friendly titanium alloy polishing liquid is poured into the PP pickling tank to immerse the titanium alloy plate and stir evenly; Step 2: Heat the temperature of the environmentally friendly titanium alloy polishing liquid to 55-62°C, replace the environmentally friendly titanium alloy polishing liquid every 1 hour under 40KHz, 2500W ultrasonic action, after cleaning for 3 hours, take out the titanium alloy plate, wash it twice with pure water, and then dry it at 60°C for 1 hour to complete polishing.

9. The polishing method of the environmentally friendly titanium alloy polishing liquid according to claim 8, characterized in that: In the step 2, the temperature of the environmentally friendly titanium alloy polishing liquid is heated to 59°C.

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