A method for judging the bonding state of an oxide layer to a substrate
By observing the indentation location of the oxide layer using a microhardness tester and microscope, the problem of the accuracy of the bonding between the oxide layer and the substrate was solved, providing a direct experimental basis.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- STATE POWER INVESTMENT CORPORATION RESEARCH INSTITUTE
- Filing Date
- 2024-12-12
- Publication Date
- 2026-06-12
AI Technical Summary
Existing technologies make it difficult to directly observe whether the oxide layer and the substrate will peel off and fail under stress, resulting in low accuracy in judging the bonding between the oxide layer and the substrate.
Multiple loading tests were conducted using a microhardness tester, and the indentation locations were observed using a metallographic microscope and a scanning electron microscope. The bonding between the oxide layer and the substrate was determined based on the degree of oxide layer peeling.
This allows for direct observation of whether the oxide layer will peel off from the substrate under stress, improving the accuracy and reliability of the judgment and providing an experimental basis for oxide layer growth and application.
Smart Images
Figure CN122193076A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of materials technology, specifically relating to a method for determining the bonding between the oxide layer and the substrate. Background Technology
[0002] In practical engineering applications, the formation of an oxide layer on a substrate surface has multiple characteristics and functions. For example, a dense oxide layer on the substrate surface can prevent oxygen or corrosive liquids from directly contacting the interior of the object, thereby effectively mitigating the oxidation process of the substrate and extending the service life of the workpiece. In addition, the oxide layer can also change certain physical properties of the workpiece, such as increasing hardness and wear resistance. Based on these functions, oxide layers are widely used in metal processing, ceramic production, semiconductor manufacturing, and metal protection.
[0003] The oxide layer formed on the substrate surface should have the following characteristics: (1) the oxide layer is dense, continuous, and without pores; (2) the oxide layer has a certain thickness and is well bonded to the substrate, and is not easily peeled off and fails. After the oxide layer is formed on the substrate surface, it is necessary to inspect the density, thickness, and bonding with the substrate of the oxide layer in order to understand whether the formed oxide layer is qualified. Among them, the density and thickness of the oxide layer can be directly observed and judged by characterization methods such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM). However, how to judge the bonding between the oxide layer and the substrate is particularly complicated. At present, the bonding strength between the oxide layer and the substrate is mainly judged by the following two methods: (1) the bonding between the oxide layer and the substrate is indirectly reflected by testing the strength or hardness of the oxide layer; (2) the interface between the oxide layer and the substrate is observed by characterization methods such as OM, SEM and TEM. If the oxide layer and the substrate are uniformly bonded at the interface, it is considered that the bonding between the oxide layer and the substrate is good.
[0004] However, both methods have their limitations. Method (1) generally assumes that the higher the strength or hardness of the oxide layer, the better the bond between the oxide layer and the substrate. However, this method only indirectly reflects the bond between the oxide layer and the substrate and cannot provide direct experimental evidence to prove that oxide layers with high strength or hardness are less prone to peeling failure in actual use. Therefore, this method is not very accurate. Method (2), which uses OM, SEM, and TEM to observe uniform bonding between the oxide layer and the substrate at the interface, primarily demonstrates good oxide layer growth. Whether it will peel off during actual use under stress is completely unknown, so this method is also not very accurate.
[0005] Therefore, exploring a new experimental method to directly observe whether the oxide layer will peel off from the substrate under stress can more intuitively reflect the bonding between the oxide layer and the substrate, and can provide an experimental and theoretical basis for the growth and subsequent application of the oxide layer. Summary of the Invention
[0006] This invention aims to at least partially address one of the technical problems in related technologies. To this end, embodiments of this invention propose a method for determining the bonding between the oxide layer and the substrate.
[0007] This invention provides a method for determining the bonding between an oxide layer and a substrate, comprising the following steps:
[0008] S1. Provide multiple test samples, the test samples including a substrate and an oxide layer disposed on the surface of the substrate;
[0009] S2. Select one of the test samples from the plurality of test samples, and perform a first microhardness test on the surface of the selected test sample using a microhardness tester, wherein the loading load of the first microhardness test includes N1, N2, N3, N4, and N5, where N1 <N2<N3<N4<N5;
[0010] S3. Use a metallographic microscope to observe the morphology of the indentation location of the test sample that has undergone the first microhardness test, and use the loading load that can clearly observe the microindentation as the standard loading load.
[0011] S4. A second microhardness test is performed on the surface of each of the test samples using the microhardness tester, wherein the loading load of the second microhardness test is the standard loading load;
[0012] S5. The morphology of the indentation location of the test sample that has undergone the second microhardness test is observed using the metallographic microscope and / or scanning electron microscope, respectively.
[0013] S6. Sort the oxide layer peeling conditions of different test samples, and sort the oxide layer and substrate bonding conditions of different test samples according to the sorting of oxide layer peeling conditions. The less severe the oxide layer peeling, the better the bonding condition between the oxide layer and the substrate.
[0014] The advantages and technical effects of the method in this embodiment of the invention are as follows:
[0015] (1) The method of the present invention can directly observe whether the oxide layer will peel off from the substrate under stress, and can more intuitively reflect the bonding between the oxide layer and the substrate, which can provide an experimental and theoretical basis for the growth of the oxide layer and its subsequent application.
[0016] (2) The method of the present invention is simple and convenient to operate, low in cost and accurate in judgment results.
[0017] In some embodiments, in step S1, the substrate includes at least one of metal, alloy, semiconductor and ceramic.
[0018] In some embodiments, in step S1, the substrates of the plurality of test samples are made of the same material.
[0019] In some embodiments, in step S1, the substrates of the plurality of test samples are all identical.
[0020] In some embodiments, in step S2, N1 = 5-20g, and / or, N2 = 80-120g, and / or, N3 = 180-220g, and / or, N4 = 480-520g, and / or, N5 = 900-1000g.
[0021] In some embodiments, in step S2, the loading load of the first microhardness test further includes N6, where N6 = 280-320g.
[0022] In some embodiments, in step S2, the loading load of the first microhardness test further includes N7, where N7 = 380–420 g.
[0023] In some embodiments, in step S2, the loading load of the first microhardness test further includes N8, where N8 = 580-620g.
[0024] In some embodiments, in step S2, the loading load of the first microhardness test further includes N9, where N9 = 680-720g.
[0025] In some embodiments, the loading load of the first microhardness test in step S2 further includes N. 10 N 10 =780~820g.
[0026] In some embodiments, in step S3, the morphology of the indentation location of the test sample that has undergone the first microhardness test is observed using a metallographic microscope, wherein the magnification of the metallographic microscope is 1000x or less.
[0027] In some embodiments, in step S3, the minimum load at which the microindentation can be clearly observed is used as the standard load. Attached Figure Description
[0028] Figure 1OM images of the microindentation at 500x and 1000x are shown when the load is set to 200g.
[0029] Figure 2 The SEM image of the micro-indentation area is shown when the heat preservation time is 30 min;
[0030] Figure 3 The SEM image of the micro-indentation area is shown when the heat preservation time is 45 min;
[0031] Figure 4 SEM images of the micro-indentation area are shown when the heat preservation time is 1 hour.
[0032] Figure 5 The SEM image of the micro-indentation area is shown when the heat preservation time is 2 hours. Detailed Implementation
[0033] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.
[0034] This invention provides a method for determining the bonding between an oxide layer and a substrate, comprising the following steps:
[0035] S1. Provide multiple test samples, the test samples including a substrate and an oxide layer disposed on the surface of the substrate;
[0036] S2. Select one of the test samples from the plurality of test samples, and perform a first microhardness test on the surface of the selected test sample using a microhardness tester, wherein the loading load of the first microhardness test includes N1, N2, N3, N4, and N5, where N1 <N2<N3<N4<N5;
[0037] S3. Use a metallographic microscope to observe the morphology of the indentation location of the test sample that has undergone the first microhardness test, and use the loading load that can clearly observe the microindentation as the standard loading load.
[0038] S4. A second microhardness test is performed on the surface of each of the test samples using the microhardness tester, wherein the loading load of the second microhardness test is the standard loading load;
[0039] S5. The morphology of the indentation location of the test sample that has undergone the second microhardness test is observed using the metallurgical microscope (OM) and / or scanning electron microscope (SEM).
[0040] S6. Sort the oxide layer peeling conditions of different test samples, and sort the oxide layer and substrate bonding conditions of different test samples according to the sorting of oxide layer peeling conditions. The less severe the oxide layer peeling, the better the bonding condition between the oxide layer and the substrate.
[0041] The method of this embodiment first obtains a standard loading load through steps S2 and S3. Although step S2 is the first microhardness test performed on one of the multiple test samples, the standard loading load obtained is basically applicable to each test sample because the bonding between the oxide layer and the substrate of the multiple test samples is not particularly different. After step S4, a second microhardness test is performed on the surface of each test sample. When step S5 is performed to observe the morphology of the indentation position on the surface of each test sample using OM and / or SEM, the indentation position is also clearly visible.
[0042] The method of this embodiment first obtains a standard loading load through steps S2 and S3. In step S3, the loading load on which the micro-indentation can be clearly observed is used as the standard loading load. For example, if the micro-indentation observed under conditions N1, N2, and N3 is blurry, but can be clearly observed under conditions N4 or N5, then N4 to N5 can be selected as the standard loading load, or N4 can be selected as the standard loading load. As another example, if the micro-indentation observed under conditions N1, N2, and N3 is blurry, but can be clearly observed under condition N4, but the test sample cracks under condition N5, then only N4 can be selected as the standard loading load.
[0043] The method of this embodiment of the invention performs a microhardness test on the surface of each test sample under the same standard loading load in step S4 to ensure that the stress on the oxide layer of each test sample is consistent. Then, in step S5, the morphology of the indentation locations formed on the surface of each test sample is observed using OM and / or SEM. Finally, in step S6, the bonding between the oxide layer and the substrate is determined based on the degree of oxide layer peeling at the indentation locations on the surfaces of different test samples. Since step S5 of the method of this embodiment of the invention can directly observe whether the oxide layer will peel off from the substrate under stress, it can more intuitively reflect the bonding between the oxide layer and the substrate, so the judgment result of step S6 is accurate and reliable.
[0044] In this embodiment of the invention, step S5 involves observing the morphology of the indentation locations formed on the surface of each test sample using OM and / or SEM. In step S3, OM is used for preliminary observation when selecting a suitable standard loading load. In subsequent step S5, SEM is used for more in-depth microscopic analysis when observing the indentation locations, or OM and SEM can be combined for analysis. Furthermore, when the bonding between the oxide layer and the substrate deteriorates further, oxide layer peeling can be observed using only OM. Therefore, step S5 utilizes OM and / or SEM for analysis.
[0045] In some embodiments, in step S1, the substrate includes, but is not limited to, at least one of metals, alloys, semiconductors, and ceramics. The method of this embodiment does not particularly limit the type of test sample to which it is applicable; the substrate material of these test samples can be any material in the related art, as long as it can be protected by an oxide layer.
[0046] In some embodiments, in step S1, the substrates of the multiple test samples are made of the same material. Using the same material for the substrate of each test sample ensures that the judgment result in step S6 is more accurate.
[0047] In some embodiments, in step S1, the substrates of the multiple test samples are all identical. Identical substrates for multiple test samples include, but are not limited to, using the same material, having the same thickness, and having the same shape, etc. Having identical substrates for multiple test samples can further improve the accuracy of the judgment result in step S6.
[0048] The selected load values of the loading loads N1 to N5 in step S2 of the method embodiment of the present invention may vary due to differences in the composition and microstructure of the test sample. It is sufficient to ensure that the loads do not cause large-area cracking of the test sample and are easily observable under OM (Obstacle Course). Regarding how to set the specific values of the loading loads N1 to N5 in step S2, the following example illustrates this: For example, for a test sample using a zirconium-based alloy as a substrate, in step S2, N1 = 5–20 g, and / or, N2 = 80–120 g, and / or, N3 = 180–220 g, and / or, N4 = 480–520 g, and / or, N5 = 900–1000 g.
[0049] The loading load for the first microhardness test set in step S2 of the method embodiment of the present invention may include, but is not limited to, N1, N2, N3, N4, N5, etc. The standard loading load may include the range N1 to N5, but this does not mean that the loading load for the first microhardness test set in step S2 cannot be other ranges. Optionally, the loading load for the first microhardness test may also include N6, where N6 = 280–320 g. Optionally, the loading load for the first microhardness test may also include N7, where N7 = 380–420 g. Optionally, the loading load for the first microhardness test may also include N8, where N8 = 580–620 g. Optionally, the loading load for the first microhardness test may also include N9, where N9 = 680–720 g. Optionally, the loading load for the first microhardness test may also include N... 10 N 10 =780~820g.
[0050] In some embodiments, in step S3, the morphology of the indentation location of the test sample that has undergone the first microhardness test is observed using a metallographic microscope, wherein the magnification of the metallographic microscope is 1000x or less. Because metallographic observation can still be understood as macroscopic observation, the observation of the micro-indentation in step S3 needs to be performed at a relatively appropriate magnification, and it is not recommended to observe at excessively high magnification, as too much microscopic detail is not meaningful.
[0051] In some embodiments, in step S3, the minimum loading load at which the microindentation can be clearly observed is used as the standard loading load. For example, if the microindentation observed under conditions N1, N2, and N3 is indistinct, but the microindentation can be clearly observed under conditions N4 or N5, then N4 to N5 can be selected as the standard loading load, or N4 can be selected as the standard loading load. Preferably, the minimum loading load N4 at which the microindentation can be clearly observed is used as the standard loading load.
[0052] The present invention will now be described in detail with reference to the embodiments and accompanying drawings.
[0053] Example 1
[0054] A method for determining the bonding between the oxide layer and the substrate by microhardness loading is performed according to the following steps:
[0055] (1) By selecting different heat preservation times, oxide layers of varying thicknesses are formed on multiple substrate surfaces:
[0056] First, zirconium-based alloy samples measuring 10mm × 8mm × 2mm were cut using a wire EDM machine to form four substrates. Then, each of the four substrates was sequentially subjected to a heat treatment to form an oxide layer on its surface. The heat treatment temperature was set at 550℃. The heat treatment time for the first substrate was 30 minutes, for the second substrate 45 minutes, for the third substrate 1 hour, and for the fourth substrate 2 hours, resulting in the fourth set of test samples.
[0057] (2) Set the loading load of the microhardness tester to N1=10g, N2=100g, N3=200g, N4=500g and N5=800g in sequence, and conduct the first microhardness test on the surface of any group of test samples.
[0058] (3) Use a metallographic microscope to observe the morphology of the surface indentation position of the test sample that has undergone the first microhardness test, and take the minimum loading load that can clearly observe the microindentation as the standard loading load.
[0059] When the applied load was 10g or 100g, no obvious micro-indentations were observed at magnifications of 500x and 1000x. When the applied load was 200g, the OM results were as follows: Figure 1 As shown in the left image, the location of the indentation is as follows: Figure 1 As shown by the arrow in the left image, the peeling around the micro-indentation is still blurry and difficult to observe at 500x magnification. When magnified to 1000x, the OM result is as follows... Figure 1 As shown in the right figure, the location of the indentation is as follows: Figure 1 As shown by the arrow in the right image, the peeling around the microindentation remains blurry and difficult to observe even at 1000x magnification. When the load is 500g, the microindentation size is moderate, facilitating subsequent observation. When the load is 1000g, the test sample cracks. Therefore, 500g is chosen as the standard load.
[0060] (4) The surface of the four test samples was subjected to a second microhardness test in sequence. The loading load of the second microhardness test of the four test samples was 500g.
[0061] (5) The morphology of the indentation sites on the surfaces of the four groups of test samples that underwent the second microhardness test was observed using OM and SEM characterization methods. The OM results of the four groups of test samples are not shown. The SEM results of the first group of test samples are shown below. Figure 2 As shown, the SEM results of the second group of test samples are as follows: Figure 3 As shown, the SEM results of the third group of test samples are as follows: Figure 4 As shown, the SEM results of the fourth group of test samples are as follows: Figure 5As shown, in the SEM images of each test sample, the left image has a smaller magnification, while the right image has a larger magnification.
[0062] (5) Determine the bonding between the oxide layer and the substrate under different heat preservation times based on the peeling of the oxide layer at the indentation location, and select the optimal heat preservation time accordingly.
[0063] Depend on Figure 2 It can be seen that when the holding time is 30 minutes, the oxide layer in the indentation area is tightly bonded, and no oxide layer peeling behavior is observed. When the holding time is 45 minutes, slight oxide layer peeling behavior occurs in the indentation area, and oxide layer cracking is observed, such as... Figure 3 As shown by the middle arrow, when the heat preservation time was increased to 1 hour, the oxide layer exhibited significant peeling and flaking behavior, as shown... Figure 4 As indicated by the middle arrow, when the heat preservation time was further increased to 2 hours, the peeling and detachment of the oxide layer intensified further, as shown in the image. Figure 5 As indicated by the middle arrow.
[0064] Therefore, the experimental results show that when the holding time is 30 min, the oxide layer bonds well with the substrate and is not prone to peeling failure under external force. When the holding time is 45 min, the oxide layer begins to peel off and cracking can be observed, indicating poor bonding between the oxide layer and the substrate. When the holding time is further increased to 1 h and 2 h, the peeling off of the oxide layer intensifies, and the bonding between the oxide layer and the substrate is the worst, making it unsuitable for practical industrial applications.
[0065] In summary, the experimental results show that when the holding temperature is 550℃, the optimal holding time for the zirconium-based alloy used in this embodiment to form a well-bonded oxide layer is 30 minutes.
[0066] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0067] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A method for determining the bonding between an oxide layer and a substrate, characterized in that, Includes the following steps: S1. Provide multiple test samples, the test samples including a substrate and an oxide layer disposed on the surface of the substrate; S2. Select one of the test samples from the plurality of test samples, and perform a first microhardness test on the surface of the selected test sample using a microhardness tester, wherein the loading load of the first microhardness test includes N1, N2, N3, N4, and N5, where N1 <N2<N3<N4<N5; S3. Use a metallographic microscope to observe the morphology of the indentation location of the test sample that has undergone the first microhardness test, and use the loading load that can clearly observe the microindentation as the standard loading load. S4. A second microhardness test is performed on the surface of each of the test samples using the microhardness tester, wherein the loading load of the second microhardness test is the standard loading load; S5. The morphology of the indentation location of the test sample that has undergone the second microhardness test is observed using the metallographic microscope and / or scanning electron microscope, respectively. S6. Sort the oxide layer peeling conditions of different test samples, and sort the oxide layer and substrate bonding conditions of different test samples according to the sorting of oxide layer peeling conditions. The less severe the oxide layer peeling, the better the bonding condition between the oxide layer and the substrate.
2. The method according to claim 1, characterized in that, In step S1, the substrate includes at least one of metal, alloy, semiconductor and ceramic.
3. The method according to claim 1, characterized in that, In step S1, the substrates of the multiple test samples are all made of the same material.
4. The method according to claim 3, characterized in that, In step S1, the substrates of the multiple test samples are all identical.
5. The method according to claim 1, characterized in that, In step S2, N1 = 5-20g, and / or, N2 = 80-120g, and / or, N3 = 180-220g, and / or, N4 = 480-520g, and / or, N5 = 900-1000g.
6. The method according to claim 1 or 5, characterized in that, In step S2, the loading load of the first microhardness test further includes N6, where N6 = 280-320g; and / or, the loading load of the first microhardness test further includes N7, where N7 = 380-420g.
7. The method according to claim 1 or 5, characterized in that, In step S2, the loading load of the first microhardness test further includes N8, where N8 = 580–620 g; and / or, the loading load of the first microhardness test further includes N9, where N9 = 680–720 g; and / or, the loading load of the first microhardness test further includes N... 10 N 10 =780~820g.
8. The method according to claim 1, characterized in that, In step S3, the morphology of the indentation location of the test sample that has undergone the first microhardness test is observed using a metallographic microscope, wherein the magnification of the metallographic microscope is less than 1000x.
9. The method according to claim 1, characterized in that, In step S3, the minimum loading load that allows for clear observation of micro-indentations is used as the standard loading load.