Method for displaying gamma'strengthening phase of high-temperature alloy
By using a corrosion agent made of a mixture of phosphoric acid solution, Cr2O3 and water for electrolytic corrosion, the problem of difficult to clearly display the more microscopic γ′ reinforced phase in high-temperature alloys in the prior art is solved, and an efficient and clear display effect is achieved, which promotes further analysis of the γ′ reinforced phase.
Patent Information
- Application Number
- CN202510019561.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-07
- Publication Date
- 2025-04-11
AI Technical Summary
The prior art is difficult to clearly display the more microscopic nano-micrometer-sized secondary γ′ phase and triad γ′ phase in high-temperature alloys, and there is a situation where the γ′ reinforced phase is corroded to form a pit, which affects further analysis.
The electrolytic corrosion is carried out using a corrosion agent made of a mixture of phosphoric acid solution, Cr2O3 and water. Through the coordination of Cr2O3 with phosphoric acid, the current and time of electrolytic corrosion are reduced, the corrosion efficiency is improved, and the clear display of the γ′ strengthened phase is promoted.
It realizes a clear display of the more microscopic secondary γ′ phase and the triad γ′ phase in high-temperature alloys, which is simple, safe and efficient in operation, and reduces the blur of phase boundaries, which is conducive to further analysis and research.
Smart Images
Figure CN119804077A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of physical and chemical detection, and in particular to a method for displaying a γ′ strengthening phase of a high-temperature alloy. Background Art
[0002] The γ′ strengthening phase is an important precipitation strengthening phase in high-temperature alloys. Its chemical formula is Ni3(Al, Ti), and it is sometimes expressed as L12-type compounds such as Ni3Al and Ni3Ti. It is an intermetallic compound formed by the combination of aluminum atoms that are easily enriched around dislocations in the interface area and nickel and titanium (or other elements, such as tantalum) atoms in the matrix. The γ′ strengthening phase is of great significance in improving the strength, fatigue resistance, creep and other properties of high-temperature alloys. The more microscopic secondary γ′ phase or tertiary γ′ phase of the γ′ strengthening phase is usually formed after heat treatment.
[0003] At present, the microstructure etchants specified in the high-temperature alloy standards, such as the etchants composed of a mixture of copper sulfate, hydrochloric acid, and anhydrous ethanol, can only display the structure under a light microscope. For the more microscopic γ′ strengthening phase, especially the secondary γ′ phase and tertiary γ′ phase of nanometer and micrometer size in high-temperature alloy forgings, the display effect is poor. There is even a situation where the γ′ strengthening phase is corroded to form pits, which makes it difficult to further analyze the γ′ strengthening phase.
[0004] In the prior art, CN113049347A discloses a metallographic etchant for precipitation-strengthening high-temperature alloys and a method for using the same, which specifically discloses a metallographic etchant composed of an acid substance and an organic corrosion inhibitor for displaying a γ′ strengthening phase. However, the metallographic etchant provided can only clearly display the primary γ′ strengthening phase, and the display of the secondary γ′ phase and the tertiary γ′ phase is still relatively vague. Summary of the invention
[0005] In order to solve the above technical problems, the present invention provides a method for displaying the γ′ strengthening phase of a high-temperature alloy, which effectively solves the problem of unclear corrosion display of the secondary γ′ phase or the tertiary γ′ phase of the more microscopic nanometer-micrometer scale of the γ′ strengthening phase of the high-temperature alloy.
[0006] The technical solution of the present invention to solve the above technical problems is as follows:
[0007] A method for displaying a γ′ strengthening phase of a high-temperature alloy, comprising:
[0008] Placing the sample to be tested in a corrosive agent for electrolytic corrosion;
[0009] The samples after electrolytic corrosion were taken out and tested to show the γ′ strengthening phase;
[0010] The corrosive agent is a mixture of phosphoric acid solution, Cr2O3 and water.
[0011] In a specific embodiment of the present invention, the volume ratio of the phosphoric acid solution to water is 10-50:50-90.
[0012] In a specific embodiment of the present invention, the mass volume ratio of Cr2O3 to phosphoric acid solution is 2-10:10-50; wherein the unit of mass volume ratio is g / mL.
[0013] In a specific embodiment of the present invention, the concentration of the phosphoric acid solution is 75-85 wt %.
[0014] In a specific embodiment of the present invention, the current of the electrolytic corrosion is 0.5-1.5A.
[0015] In a specific embodiment of the present invention, the electrolytic corrosion time is 10 to 60 seconds.
[0016] In a specific embodiment of the present invention, the γ′ strengthening phase is a secondary γ′ phase and / or a tertiary γ′ phase of a high temperature alloy forging.
[0017] In a specific embodiment of the present invention, the detection is performed using a scanning electron microscope.
[0018] In a specific embodiment of the present invention, before the electrolytic corrosion of the sample to be tested, the surface of the sample to be tested is ground and polished.
[0019] In a specific embodiment of the present invention, the grinding and polishing process uses sandpaper and / or flannel cloth.
[0020] In the etchant of the present invention, Cr2O3 cooperates with phosphoric acid to carry out electrolytic corrosion, which can reduce the current and time of electrolytic corrosion and improve the efficiency of electrolytic corrosion; Cr2O3 can dissolve in a solution of phosphoric acid and water and generate chromic acid, which increases the secondary γ′ phase and tertiary γ′ phase grain boundary corrosion of the γ′ strengthening phase and promotes the clear display of the secondary γ′ phase and tertiary γ′ phase under a scanning electron microscope with a high magnification.
[0021] The beneficial effects of the present invention are:
[0022] 1. The present invention solves the problem of corrosion display of secondary γ′ phase and tertiary γ′ phase with a more microscopic nanometer size of γ′ strengthening phase, and can clearly display the secondary γ′ phase and tertiary γ′ phase, with simple, safe, efficient and high reproducibility operation;
[0023] 2. In the corrosive agent of the present invention, phosphoric acid can corrode high-temperature alloys, which is beneficial to the corrosion display of the secondary γ′ phase which is more microscopic than the γ′ strengthening phase. Cr2O3 can promote the corrosion display of the tertiary γ′ phase and reduce the blurring of the phase boundary, which is beneficial to the further analysis and research of the secondary γ′ phase and the tertiary γ′ phase which are more microscopic than the γ′ strengthening phase. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 This is a morphological photograph of the microstructure of the GH4698 high-temperature alloy forging under 50kx in Example 1 of the present invention;
[0025] Figure 2 This is a morphology photograph of the microstructure of the GH4033 high-temperature alloy forging under 100kx in Example 2 of the present invention;
[0026] Figure 3 This is a morphology photograph of the microstructure of the GH4698 high-temperature alloy forging of the comparative example 1 of the present invention under 30kx;
[0027] Figure 4 This is a morphological photograph of the microstructure of the GH4698 high-temperature alloy forging of the comparative example 2 of the present invention under 30kx. DETAILED DESCRIPTION
[0028] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.
[0029] A method for displaying a γ′ strengthening phase of a high-temperature alloy, comprising:
[0030] Placing the sample to be tested in a corrosive agent for electrolytic corrosion;
[0031] The samples after electrolytic corrosion were taken out and tested to show the γ′ strengthening phase;
[0032] The corrosive agent is a mixture of phosphoric acid solution, Cr2O3 and water.
[0033] In some examples, the volume ratio of the phosphoric acid solution to water is 10-50:50-90.
[0034] In some examples, the mass volume ratio of Cr2O3 to phosphoric acid solution is 2-10:10-50; wherein the unit of mass volume ratio is g / mL.
[0035] In some examples, the concentration of the phosphoric acid solution is 75-85 wt %.
[0036] In some examples, the current of the electrolytic corrosion is 0.5-1.5A.
[0037] In some examples, the electrolytic corrosion time is 10 to 60 seconds.
[0038] In some examples, the γ′ strengthening phase is a secondary γ′ phase and / or a tertiary γ′ phase of a high temperature alloy forging.
[0039] In some examples, the detecting is performed using a scanning electron microscope.
[0040] In some examples, before the electrolytic corrosion of the sample to be tested, the surface of the sample to be tested is ground and polished.
[0041] In some examples, the grinding and polishing process uses sandpaper and / or velvet cloth.
[0042] In order to further demonstrate the effect of the etchant of the present invention on improving the γ′ strengthening phase display of high temperature alloys, the following examples and comparative examples are provided:
[0043] Example 1
[0044] This embodiment provides a method for displaying a γ′ strengthening phase of a high-temperature alloy, comprising the following steps:
[0045] The surface to be tested of the GH4698 high temperature alloy forging specimen was polished with sandpaper and flannel cloth;
[0046] Take 40 mL of 85 wt % phosphoric acid solution, 90 mL of deionized water, and 6 g of analytically pure chromium trioxide (Cr2O3) and mix them to obtain an etchant;
[0047] The polished sample was placed in an etchant and electrolytically corroded for 50 seconds at a current of 1.2A, and then taken out;
[0048] Clean the surface of the specimen to be tested with sewage ethanol;
[0049] Scanning electron microscopy was used to examine the tested surface, showing the γ′ strengthening phase of the high-temperature alloy forging.
[0050] The morphology of the microstructure of the GH4698 high-temperature alloy forging in this example under 50kx is shown in the figure. Figure 1 shown.
[0051] Example 2
[0052] This embodiment provides a method for displaying a γ′ strengthening phase of a high-temperature alloy, comprising the following steps:
[0053] The surface to be tested of the GH4033 high temperature alloy forging specimen was polished with sandpaper and flannel cloth;
[0054] Take 40 mL of 85 wt % phosphoric acid solution, 90 mL of deionized water, and 4 g of analytically pure chromium trioxide (Cr2O3) and mix them to obtain an etchant;
[0055] The polished sample was placed in an etchant and etched for 60 seconds at a current of 0.5A, then taken out;
[0056] Clean the surface of the specimen to be tested with sewage ethanol;
[0057] Scanning electron microscopy was used to examine the tested surface, showing the γ′ strengthening phase of the high-temperature alloy forging.
[0058] The morphology of the microstructure of the GH4033 high-temperature alloy forging in this example at 100kx is shown in the figure. Figure 2 shown.
[0059] Comparative Example 1
[0060] This comparative example provides a method for displaying a γ′ strengthening phase in a high-temperature alloy, comprising the following steps:
[0061] The surface to be tested of the GH4698 high temperature alloy forging specimen was polished with sandpaper and flannel cloth;
[0062] Take 40 mL of 85 wt % phosphoric acid solution and 90 mL of deionized water and mix them to obtain an etchant;
[0063] The polished sample was placed in an etchant and electrolytically corroded for 120 seconds at a current of 1.6A, and then taken out;
[0064] Clean the surface of the specimen to be tested with sewage ethanol;
[0065] Scanning electron microscopy was used to examine the tested surface, showing the γ′ strengthening phase of the high-temperature alloy forging.
[0066] The morphology of the microstructure of the GH4698 high-temperature alloy forging in this comparative example at 30kx is shown in the figure. Figure 3 shown.
[0067] Comparative Example 2
[0068] This embodiment provides a method for displaying a γ′ strengthening phase of a high-temperature alloy, comprising the following steps:
[0069] The surface to be tested of the GH4698 high temperature alloy forging specimen was polished with sandpaper and flannel cloth;
[0070] Take 1.5 g of analytical pure CuSO4, 40 mL of analytical pure hydrochloric acid, and 20 mL of anhydrous ethanol and mix them to obtain a corrosive agent;
[0071] Place the polished sample in the corrosive agent for 30 seconds and take it out;
[0072] Clean the surface of the specimen to be tested with sewage ethanol;
[0073] Scanning electron microscopy was used to examine the tested surface, showing the γ′ strengthening phase of the high-temperature alloy forging.
[0074] The morphology of the microstructure of the GH4698 high-temperature alloy forging in this comparative example at 30kx is shown in the figure. Figure 4 shown.
Claims
1. A method for displaying a γ′ strengthening phase of a high temperature alloy, characterized in that: include: Placing the sample to be tested in a corrosive agent for electrolytic corrosion; The samples after electrolytic corrosion were taken out and tested to show the γ′ strengthening phase; The corrosive agent is a mixture of phosphoric acid solution, Cr2O3 and water.
2. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 1, characterized in that: The volume ratio of the phosphoric acid solution to water is 10-50:50-90.
3. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 1, characterized in that: The mass volume ratio of the Cr2O3 to the phosphoric acid solution is 2-10:10-50.
4. The method for displaying the γ′ strengthening phase of a high-temperature alloy according to any one of claims 1 to 3, characterized in that: The concentration of the phosphoric acid solution is 75-85 wt %.
5. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 1, characterized in that: The current of the electrolytic corrosion is 0.5-1.5A.
6. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 1, characterized in that: The electrolytic corrosion time is 10 to 60 seconds.
7. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 1, characterized in that: The γ′ strengthening phase is a secondary γ′ phase and / or a tertiary γ′ phase of a high temperature alloy forging.
8. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 1, characterized in that: The detection was performed using a scanning electron microscope.
9. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 1, characterized in that: Before the electrolytic corrosion of the test sample, the surface of the test sample is ground and polished.
10. The method for displaying the γ′ strengthening phase of a high temperature alloy according to claim 9, characterized in that: The grinding and polishing process uses sandpaper and / or flannel cloth.