Electrolyte, surface treatment method and characterization method of high strain rate rare earth magnesium alloy

Abstract

The invention discloses an electrolyte, a surface treatment method and a characterization method for a high strain rate rare earth magnesium alloy, which solves the technical problem in the prior art that the conventional electrolyte cannot effectively treat the surface of the high strain rate rare earth magnesium alloy, thereby affecting the characterization effect. The electrolyte is composed of anhydrous ethanol, distilled water, n-butanol, sodium thiocyanate, glacial acetic acid, citric acid and perchloric acid. The preparation method of the electrolyte comprises the following steps: firstly, anhydrous ethanol, distilled water and n-butanol are mixed; then citric acid is added; after the citric acid is completely dissolved, sodium thiocyanate is added; after the sodium thiocyanate is completely dissolved, glacial acetic acid is added; and finally perchloric acid is added. The surface treatment method comprises the steps of: electrolyzing the high strain rate rare earth magnesium alloy with the electrolyte. The characterization method comprises the following steps: performing SEM and EBSD tests on the electrolyzed high strain rate rare earth magnesium alloy.

Description

Technical Field

[0001] The invention relates to the technical field of characterization of high strain rate rare earth magnesium alloys, and in particular to an electrolyte, a surface treatment method and a characterization method of a high strain rate rare earth magnesium alloy. Background Art

[0002] The rare earth magnesium alloy prepared by adding an appropriate amount of rare earth elements to the magnesium alloy has significantly better properties than the magnesium alloy, such as finer alloy structure, better mechanical properties, heat resistance and corrosion resistance.

[0003] When the rare earth magnesium alloy is subjected to high strain rate strain (such as loading with a first-stage light gas gun), the rare earth magnesium alloy is prone to delamination. The second phase in the delamination pores will be stretched, causing the surface of the rare earth magnesium alloy to be blocked, thereby affecting the effect of characterizing the rare earth magnesium alloy under an electron microscope. Therefore, the surface of the high strain rate rare earth magnesium alloy needs to be treated before electron microscope characterization.

[0004] However, there are many methods for characterizing rare earth magnesium alloys with low and medium strain rates, but the characterization methods for rare earth magnesium alloys with high strain rates are not yet mature. Electrolytic treatment is a commonly used surface treatment method. The electrolyte used in existing magnesium alloys is usually composed of perchloric acid and anhydrous ethanol. The applicant of this application found that the traditional electrolyte cannot effectively treat the surface of high strain rate rare earth magnesium alloys. Summary of the invention

[0005] In a first aspect, the present invention aims to provide an electrolyte for electron microscopy characterization of high strain rate rare earth magnesium alloys, so as to solve the technical problem in the prior art that conventional electrolytes cannot effectively treat the surface of high strain rate rare earth magnesium alloys.

[0006] In order to achieve the purpose of the first aspect, the present invention provides an electrolyte for electron microscopy characterization of high strain rate rare earth magnesium alloys, and the technical solution is as follows:

[0007] The electrolyte used for electron microscope characterization of high strain rate rare earth magnesium alloy is composed of anhydrous ethanol, distilled water, n-butanol, sodium thiocyanate, glacial acetic acid, citric acid and perchloric acid.

[0008] Furthermore, the electrolyte is composed of 700-900 mL of anhydrous ethanol, 16-20 mL of distilled water, 80-120 mL of n-butanol, 40-45 g of sodium thiocyanate, 8-12 mL of glacial acetic acid, 70-80 g of citric acid and 18-23 mL of perchloric acid.

[0009] Furthermore, the high strain rate rare earth magnesium alloy contains Nd, Zn, Zr, Cu and Ni.

[0010] Furthermore, the high strain rate rare earth magnesium alloy is obtained by impacting a rare earth magnesium alloy sample with a first-stage light gas gun.

[0011] Secondly, the purpose of the present invention is to provide a method for preparing an electrolyte for electron microscopy characterization of high strain rate rare earth magnesium alloys, so as to solve the technical problem in the prior art that an electrolyte capable of effectively treating the surface of high strain rate rare earth magnesium alloys cannot be obtained.

[0012] In order to achieve the purpose of the second aspect, the present invention provides a method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy, and the technical scheme is as follows:

[0013] The invention discloses a method for preparing an electrolyte for electron microscope characterization of a high strain rate rare earth magnesium alloy, comprising the following steps: firstly, anhydrous ethanol, distilled water and n-butanol are mixed; then, citric acid is added; after the citric acid is completely dissolved, sodium thiocyanate is added; after the sodium thiocyanate is completely dissolved, glacial acetic acid is added; and finally, perchloric acid is added.

[0014] In a third aspect, the present invention aims to provide a surface treatment method for high strain rate rare earth magnesium alloys to solve the technical problem in the prior art that the surface of high strain rate rare earth magnesium alloys is difficult to effectively treat.

[0015] In order to achieve the purpose of the third aspect, the present invention provides a surface treatment method for a high strain rate rare earth magnesium alloy, and the technical solution is as follows:

[0016] The surface treatment method of a high strain rate rare earth magnesium alloy comprises the steps of: obtaining the electrolyte described in the first aspect, or obtaining the electrolyte prepared by the preparation method described in the second aspect; and electrolyzing the high strain rate rare earth magnesium alloy using the obtained electrolyte.

[0017] Furthermore, the method further comprises pre-treating the high strain rate rare earth magnesium alloy before electrolysis, wherein the pre-treatment comprises polishing and cleaning.

[0018] Furthermore, the polishing uses 1000#, 1600#, 2000#, and 3000# sandpaper in sequence; and the cleaning uses anhydrous ethanol for ultrasonic cleaning.

[0019] Furthermore, during electrolysis, the temperature is -15 to -30°C, the voltage is 15 to 18V, the current is 0.05 to 0.08A, and the duration is 80 to 120s.

[0020] In a fourth aspect, the present invention aims to provide a method for characterizing a high strain rate rare earth magnesium alloy, so as to solve the technical problem that high strain rate rare earth magnesium alloy is difficult to characterize in the prior art.

[0021] In order to achieve the purpose of the fourth aspect, the present invention provides a characterization method for a high strain rate rare earth magnesium alloy, and the technical solution is as follows:

[0022] The characterization method of the high strain rate rare earth magnesium alloy comprises the following steps: treating the high strain rate rare earth magnesium alloy by the surface treatment method described in the third aspect; and performing SEM and EBSD tests.

[0023] It has been verified that the electrolyte of the present invention is simple and easy to obtain, and can quickly treat the surface of high strain rate rare earth magnesium alloy, significantly improving the characterization effect.

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings constituting a part of the present invention are used to assist in understanding the present invention. The contents provided in the drawings and their related descriptions in the present invention can be used to explain the present invention, but do not constitute improper limitations on the present invention. In the drawings:

[0026] Figure 1 This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in Example 1 of the present invention.

[0027] Figure 2 This is an IPF diagram obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in Example 1 of the present invention.

[0028] Figure 3 This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in Example 2 of the present invention.

[0029] Figure 4 This is an IPF map obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in Example 2 of the present invention.

[0030] Figure 5 This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in Example 3 of the present invention.

[0031] Figure 6 This is an IPF diagram obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in Example 3 of the present invention.

[0032] Figure 7 This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in Example 4 of the present invention.

[0033] Figure 8This is an IPF diagram obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in Example 4 of the present invention. DETAILED DESCRIPTION

[0034] The present invention is described clearly and completely below in conjunction with the accompanying drawings. A person skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that:

[0035] The technical solutions and technical features provided in each part of the present invention, including the following description, may be combined with each other if there is no conflict.

[0036] In addition, the embodiments of the present invention involved in the following description are generally only part of the embodiments of the present invention, rather than all of the embodiments. Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] About the terms and units in the present invention: The terms "include", "have" and any variations thereof in the description and claims of the present invention and related parts are intended to cover non-exclusive inclusions.

[0038] The term "strain rate" refers to the change in strain (deformation) of a material with respect to time; the term "low strain rate" refers to a strain rate of 10 -4 -10 -1 s -1 The term "medium strain rate" refers to a strain rate of 10 2 -10 4 s -1 The term "high strain rate" refers to a strain rate of 10 5 -10 8 s -1 .

[0039] The term "first-stage light gas gun" refers to an experimental gun that directly uses light gas (hydrogen or helium) in a compressed state as the propelling fluid to drive the test projectile to accelerate in the bore and make the projectile obtain the required high speed at the muzzle.

[0040] The notation "EBSD" stands for electron backscatter diffraction.

[0041] The symbol "SEM" means scanning electron microscope.

[0042] In the following specific implementation, the composition of the rare earth magnesium alloy sample used is: 2.76% Nd, 0.36% Zn, 0.46% Zr, 0.016% Cu, 0.023% Ni, and the rest is Mg. The high strain rate rare earth magnesium alloy used is obtained by impacting the rare earth magnesium alloy sample with a first-stage light gas gun.

[0043] The specific implementation mode of the electrolyte for electron microscope characterization of high strain rate rare earth magnesium alloy of the present invention is composed of anhydrous ethanol, distilled water, n-butanol, sodium thiocyanate, glacial acetic acid, citric acid and perchloric acid.

[0044] Under the same electrolysis process, when the electrolyte consists of 700-900 mL of anhydrous ethanol, 16-20 mL of distilled water, 80-120 mL of n-butanol, 40-45 g of sodium thiocyanate, 8-12 mL of glacial acetic acid, 70-80 g of citric acid and 18-23 mL of perchloric acid, the electrolyte has the best surface treatment effect, among which:

[0045] The specific value of anhydrous ethanol can be, but is not limited to, 700 mL, 720 mL, 740 mL, 760 mL, 780 mL, 800 mL, 820 mL, 840 mL, 860 mL, 880 mL or 900 mL, wherein the most preferred value is 800 mL;

[0046] The distilled water may be, but is not limited to, 16 mL, 16.5 mL, 17 mL, 17.5 mL, 18 mL, 18.5 mL, 19 mL, 19.5 mL or 20 mL, wherein the most preferred value is 18.5 mL;

[0047] The specific value of n-butanol can be, but is not limited to, 80 mL, 85 mL, 90 mL, 95 mL, 100 mL, 105 mL, 110 mL, 115 mL or 120 mL, wherein the most preferred value is 100 mL;

[0048] The specific value of sodium thiocyanate can be, but is not limited to, 40g, 40.5g, 41g, 41.5g, 42g, 42.5g, 43g, 43.5g, 44g, 44.5g or 45g, wherein the most preferred value is 42g;

[0049] The specific value of glacial acetic acid can be, but is not limited to, 8 mL, 8.5 mL, 9 mL, 9.5 mL, 10 mL, 10.5 mL, 11 mL, 11.5 mL or 12 mL, wherein the most preferred value is 10 mL;

[0050] The citric acid may be, but is not limited to, 70 g, 71 g, 72 g, 73 g, 74 g, 75 g, 76 g, 77 g, 78 g, 79 g or 80 g, wherein the most preferred value is 75 g;

[0051] The specific value of perchloric acid can be, but is not limited to, 18 mL, 19 mL, 20 mL, 21 mL, 22 mL or 23 mL, wherein the most preferred value is 20 mL.

[0052] The specific implementation of the preparation method of the electrolyte includes the following steps: firstly, anhydrous ethanol, distilled water and n-butanol are mixed; then citric acid is added; after the citric acid is completely dissolved, sodium thiocyanate is added; after the sodium thiocyanate is completely dissolved, glacial acetic acid is added; and finally perchloric acid is added. The special adding sequence can make each component evenly dispersed, so that each component can fully exert its effect, which is helpful to improve the electrolysis effect.

[0053] In order to improve the preparation efficiency of the electrolyte, stirring is preferably used in each process, and the stirring time is preferably 0.5 to 2 hours.

[0054] The specific implementation of the surface treatment method of the high strain rate rare earth magnesium alloy of the present invention comprises the steps of:

[0055] (1) pretreating the high strain rate rare earth magnesium alloy, wherein the pretreatment includes polishing and cleaning;

[0056] The polishing is to polish the surface of the high strain rate rare earth magnesium alloy with sandpaper of 1000#, 1600#, 2000# and 3000# in sequence, wherein the sandpaper is preferably white sandpaper, and the 2000# and 3000# white sandpapers are preferably wetted and then polished to a bright finish by water grinding;

[0057] The cleaning is performed by ultrasonic cleaning with anhydrous ethanol.

[0058] (2) obtaining the above-mentioned electrolyte consisting of 700-900 mL of anhydrous ethanol, 16-20 mL of distilled water, 80-120 mL of n-butanol, 40-45 g of sodium thiocyanate, 8-12 mL of glacial acetic acid, 70-80 g of citric acid and 18-23 mL of perchloric acid;

[0059] (3) electrolyzing a high strain rate rare earth magnesium alloy using the obtained electrolyte;

[0060] The temperature during electrolysis is -15 to -30°C, the voltage is 15 to 18V, the current is 0.05 to 0.08A, and the duration is 80 to 120s. When the electrolysis is completed, the surface treatment of the high strain rate rare earth magnesium alloy is completed.

[0061] Compared with the prior art, the electrolyte of the present invention can not only effectively treat the surface of the high strain rate rare earth magnesium alloy, but also requires a very short electrolysis time, which can significantly improve the efficiency of surface treatment and characterization.

[0062] The specific implementation of the characterization method of the high strain rate rare earth magnesium alloy of the present invention comprises the following steps: performing SEM and EBSD tests on the high strain rate rare earth magnesium alloy that has completed the surface treatment. Since the surface of the high strain rate rare earth magnesium alloy has been successfully treated by the electrolyte of the present invention, the crystal phase of the high strain rate rare earth magnesium alloy can be successfully photographed by SEM and EBSD, thereby obtaining information such as interface (grain boundary) parameters and detecting plastic strain.

[0063] The beneficial effects of the present invention are further illustrated by specific examples. In the following examples, the temperature during electrolysis is -25°C, the voltage is 16V, the current is 0.06A, and the duration is 100s.

[0064] Example 1

[0065] The electrolyte of this embodiment is composed of 800 mL of anhydrous ethanol, 18.5 mL of distilled water, 100 mL of n-butanol, 40-42 g of sodium thiocyanate, 10 mL of glacial acetic acid, 75 g of citric acid and 20 mL of perchloric acid.

[0066] Figure 1 This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment. Figure 2 This is the IPF map obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment.

[0067] Example 2

[0068] The electrolyte of this embodiment is composed of perchloric acid and anhydrous ethanol, and the mass fraction of perchloric acid is 10%.

[0069] Figure 3 This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment. Figure 4 This is the IPF map obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment.

[0070] Example 3

[0071] The electrolyte of this embodiment is composed of 800 mL of anhydrous ethanol, 18.5 mL of distilled water, 100 mL of n-butanol, 40-10 mL of glacial acetic acid, 75 g of citric acid and 20 mL of perchloric acid. Compared with the electrolyte of embodiment 1, the electrolyte of this embodiment does not contain sodium thiocyanate.

[0072] Figure 5This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment. Figure 6 This is the IPF map obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment.

[0073] Example 4

[0074] The electrolyte of this embodiment is composed of 800 mL of anhydrous ethanol, 18.5 mL of distilled water, 100 mL of n-butanol, 40-42 g of sodium thiocyanate, 75 g of citric acid and 20 mL of perchloric acid. Compared with the electrolyte of embodiment 1, the electrolyte of this embodiment does not contain glacial acetic acid.

[0075] Figure 7 This is a SEM photograph of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment. Figure 8 This is the IPF map obtained by EBSD testing of the high strain rate rare earth magnesium alloy after surface treatment in this embodiment.

[0076] exist Figure 1-8 In the figure, the SEM image and IPF image correspond to the same position on the surface of the high strain rate rare earth magnesium alloy.

[0077] contrast Figure 1 , 3 , 5, 7, we can see that only Figure 1 The grains of the high strain rate rare earth magnesium alloy are shown, and the grain boundaries between the grains are obvious, indicating that the electrolyte of Example 1 effectively treats the surface of the high strain rate rare earth magnesium alloy.

[0078] Likewise, compared Figure 2 , 4 , 6, 8, we can see that Figure 2 The black area in the graph has less agglomeration and a smaller area, which is more helpful for analyzing and obtaining accurate interface (grain boundary) parameters, further illustrating that the electrolyte of Example 1 effectively treats the surface of the high strain rate rare earth magnesium alloy.

[0079] By comparing Example 1 with Examples 3-4, it can be seen that sodium thiocyanate and glacial acetic acid play an important role in the electrolyte of the present invention, and neither of them can be missing.

[0080] The above is a description of the relevant contents of the present invention. A person skilled in the art will be able to implement the present invention based on these descriptions. Based on the above contents of the present invention, all other embodiments obtained by a person skilled in the art without creative work shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy, characterized in that: The electrolyte is composed of 700-900 mL of anhydrous ethanol, 16-20 mL of distilled water, 80-120 mL of n-butanol, 40-45 g of sodium thiocyanate, 8-12 mL of glacial acetic acid, 70-80 g of citric acid and 18-23 mL of perchloric acid; The preparation method comprises the following steps: First, anhydrous ethanol, distilled water, and n-butanol are mixed; Then add citric acid; After the citric acid is completely dissolved, add sodium thiocyanate; After sodium thiocyanate is completely dissolved, add glacial acetic acid; The perchloric acid was added last.

2. The method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy according to claim 1, characterized in that: The high strain rate rare earth magnesium alloy contains Nd, Zn, Zr, Cu and Ni.

3. The method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy according to claim 1, characterized in that: The high strain rate rare earth magnesium alloy is obtained by impacting a rare earth magnesium alloy sample with a first-stage light gas gun.

4. The method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy according to claim 1, characterized in that: The electrolyte is used for electrolysis of high strain rate rare earth magnesium alloy.

5. The method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy according to claim 4, characterized in that: The invention also comprises pre-treating the high strain rate rare earth magnesium alloy before electrolysis, wherein the pre-treatment comprises polishing and cleaning.

6. The method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy according to claim 5, characterized in that: The polishing uses 1000#, 1600#, 2000#, and 3000# sandpaper in sequence; the cleaning uses anhydrous ethanol for ultrasonic cleaning.

7. The method for preparing an electrolyte for electron microscopy characterization of a high strain rate rare earth magnesium alloy according to claim 4, characterized in that: During electrolysis, the temperature is -15 to -30°C, the voltage is 15 to 18V, the current is 0.05 to 0.08A, and the duration is 80 to 120s.

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