Radiation hardening coefficient generation method, radiation hardening evaluation method

Abstract

The application discloses a kind of irradiation hardening coefficient generation method, irradiation hardening evaluation method, it is related to irradiation hardening technical field.Coefficient generation method includes: to test sample is ion irradiation, and according to ion irradiation parameter simulation obtains irradiation damage depth distribution atlas;After ion irradiation, the test sample and the control sample of test sample are carried out nanoindentation test, and the first load displacement curve of test sample and the second load displacement curve of control sample are obtained;According to the first, second load displacement curve obtains the first, second simulation load displacement curve;According to the first load displacement curve, the first simulation load displacement curve and the second load displacement curve, the second simulation load displacement curve obtains the first elastic-plastic transition point, the second elastic-plastic transition point;According to the first elastic-plastic transition point, the second elastic-plastic transition point and irradiation damage depth distribution atlas obtains irradiation hardening coefficient.Thereby, it can be quantitatively evaluated to irradiation hardening.

Description

Technical Field

[0001] This invention relates to the field of radiation hardening technology, and in particular to a method for generating radiation hardening coefficient and a method for evaluating radiation hardening. Background Technology

[0002] With the development of fission and fusion reactors, the demand for structural materials capable of withstanding high-dose neutron irradiation (>100 dPa) is increasing. To simulate the neutron irradiation environment of reactors, ion irradiation has become a common method for simulating neutron irradiation damage due to its high efficiency, low cost, and lack of residual radioactivity. Since the damage layer caused by ion irradiation is relatively shallow, nanoindentation techniques are often used to assess its hardening behavior. However, during indentation, the stress field penetrates multiple irradiation-level damage regions, making it difficult to quantitatively assess radiation hardening. Summary of the Invention

[0003] This invention aims to at least partially address one of the technical problems in related art. To this end, the present invention provides a method for generating the irradiation hardening coefficient to support the quantitative assessment of irradiation hardening.

[0004] The second objective of this invention is to provide a method for evaluating radiation hardening.

[0005] To achieve the above objectives, a first aspect of the present invention provides a method for generating an irradiation hardening coefficient. The method includes: irradiating a test sample with ions and simulating an irradiation damage depth distribution map of the test sample based on ion irradiation parameters; performing nanoindentation tests on the irradiated test sample and a control sample of the test sample to obtain a first load-displacement curve of the test sample and a second load-displacement curve of the control sample; obtaining a first simulated load-displacement curve based on the first load-displacement curve and a second simulated load-displacement curve based on the second load-displacement curve; obtaining a first elastoplastic transition point based on the first load-displacement curve and the first simulated load-displacement curve, and obtaining a second elastoplastic transition point based on the second load-displacement curve and the second simulated load-displacement curve; and obtaining an irradiation hardening coefficient based on the first elastoplastic transition point, the second elastoplastic transition point, and the irradiation damage depth distribution map.

[0006] The radiation hardening coefficient generation method according to embodiments of the present invention supports quantitative evaluation of radiation hardening by generating the radiation hardening coefficient.

[0007] In addition, the irradiation hardening coefficient generation method according to embodiments of the present invention may also have the following additional technical features:

[0008] According to one embodiment of the present invention, obtaining the first elastoplastic transition point based on the first load-displacement curve and the first simulated load-displacement curve includes: obtaining a first target point with the largest abscissa among the points on the first load-displacement curve and the first simulated load-displacement curve where both the abscissa and ordinate are equal, and using the first target point as the first elastoplastic transition point; obtaining the second elastoplastic transition point based on the second load-displacement curve and the second simulated load-displacement curve includes: obtaining a second target point with the largest abscissa among the points on the second load-displacement curve and the second simulated load-displacement curve where both the abscissa and ordinate are equal, and using the second target point as the second elastoplastic transition point.

[0009] According to one embodiment of the present invention, obtaining the radiation hardening coefficient based on the first elastoplastic transition point, the second elastoplastic transition point, and the irradiation damage depth distribution map includes: obtaining a first elastic penetration depth of a first load and an indenter corresponding to the first elastoplastic transition point, and obtaining a second elastic penetration depth of a second load and an indenter corresponding to the second elastoplastic transition point; obtaining a first critical shear stress based on the first load and the first elastic penetration depth, and obtaining a second critical shear stress based on the second load and the second elastic penetration depth; and obtaining the radiation hardening coefficient based on the first critical shear stress, the second critical shear stress, and the irradiation damage depth distribution map.

[0010] According to one embodiment of the present invention, obtaining the radiation hardening coefficient based on the first critical shear stress, the second critical shear stress, and the irradiation damage depth distribution map includes: obtaining the critical shear stress change based on the first critical shear stress and the second critical shear stress, and obtaining the first irradiation damage of the test sample based on the irradiation damage depth distribution map; and obtaining the radiation hardening coefficient based on the critical shear stress change and the first irradiation damage.

[0011] According to an embodiment of the present invention, the first critical shear stress and the second critical shear stress are obtained according to the following formula:

[0012] ,

[0013] ,

[0014] in, This refers to the first critical shear stress mentioned above. Let P1 be the first load and P2 be the second load, where P1 is the second critical shear stress. This is the first elastic penetration depth. This is the second elastic penetration depth. The first effective radius of the portion of the indenter that contacts the test sample. The second effective radius is the portion of the indenter that contacts the control sample.

[0015] According to one embodiment of the present invention, obtaining the first irradiation damage of the test sample based on the irradiation damage depth distribution map includes: obtaining the depth of the elastoplastic transition of the test sample after ion irradiation; and substituting the depth of the elastoplastic transition into the irradiation damage depth distribution map to obtain the first irradiation damage.

[0016] According to one embodiment of the present invention, obtaining a first simulated load-displacement curve based on the first load-displacement curve includes: selecting a first preset number of first data points from the elastic portion of the first load-displacement curve, and obtaining a third load and a first indentation depth based on the first data points; obtaining a first effective Young's modulus based on the third load and the first indentation depth; and obtaining the first simulated load-displacement curve based on the first effective Young's modulus. Obtaining a second simulated load-displacement curve based on the second load-displacement curve includes: selecting a second preset number of second data points from the elastic portion of the second load-displacement curve, and obtaining a fourth load and a second indentation depth based on the second data points; obtaining a second effective Young's modulus based on the fourth load and the second indentation depth; and obtaining the second simulated load-displacement curve based on the second effective Young's modulus.

[0017] According to an embodiment of the present invention, the first effective Young's modulus and the second effective Young's modulus are obtained according to the following formula:

[0018] ,

[0019] ,

[0020] in, For the first load, The third elastic penetration depth, This is the first effective Young's modulus. The first effective radius of the portion of the indenter that contacts the test sample. , The depth of the first indentation. The displacement of the nanoindenter used in the aforementioned nanoindentation test due to the compliance of the load frame. For the second load, This is the second effective Young's modulus. The second effective radius of the portion of the indenter that contacts the control sample. This represents the fourth elastic penetration depth. , This is the second indentation depth.

[0021] According to one embodiment of the present invention, the radiation hardening coefficient is obtained according to the following formula:

[0022] ,

[0023] in, The radiation hardening coefficient is... This is the first type of irradiation damage. This represents the change in hardness. , The change in critical shear stress, i.e. = .

[0024] To achieve the above objectives, a second aspect of the present invention provides a method for evaluating radiation hardening, the method comprising: obtaining a second radiation damage to an article to be evaluated; and obtaining an evaluation result of radiation hardening of the article to be evaluated based on the second radiation damage and a radiation hardening coefficient, wherein the radiation hardening coefficient is a coefficient generated according to the above-described method for generating radiation hardening coefficient.

[0025] According to the radiation hardening assessment method of the present invention, the radiation hardening coefficient generated by the above-described radiation hardening coefficient generation method can be used to quantitatively assess radiation hardening.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] Figure 1 This is a flowchart of the method for generating the irradiation hardening coefficient according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of the irradiation damage depth distribution pattern of an example of the present invention;

[0029] Figure 3 This is a schematic diagram of a first load-displacement curve, a first simulated load-displacement curve, a second load-displacement curve, and a second simulated load-displacement curve, according to an example of the present invention.

[0030] Figure 4 This is a schematic diagram illustrating the depth of elastoplastic transition in an example of the present invention;

[0031] Figure 5 This is a flowchart of the irradiation hardening evaluation method according to an embodiment of the present invention;

[0032] Figure 6This is a schematic diagram of an embodiment of the radiation hardening evaluation method of the present invention. Detailed Implementation

[0033] The following description, with reference to the accompanying drawings, describes a method for generating an irradiation hardening coefficient and an irradiation hardening evaluation method according to embodiments of the present invention. Throughout the description, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described with reference to the accompanying drawings are exemplary and should not be construed as limiting the present invention.

[0034] Figure 1 This is a flowchart of the method for generating the irradiation hardening coefficient according to an embodiment of the present invention.

[0035] like Figure 1 As shown, the method for generating the irradiation hardening coefficient is characterized by comprising:

[0036] S11, the test sample is subjected to ion irradiation, and the irradiation damage depth distribution spectrum of the test sample is simulated based on the ion irradiation parameters.

[0037] Specifically, in order to achieve a quantitative assessment of radiation hardening, the test sample is first subjected to ion irradiation.

[0038] After ionizing the test sample, the irradiation damage depth distribution spectrum of the test sample can be simulated based on the ion irradiation parameters. Specifically, the irradiation damage of the test sample is calculated using SRIM or other simulation tools based on the actual irradiation parameters used during ion irradiation, and the irradiation damage depth distribution spectrum is obtained.

[0039] The above-mentioned radiation damage depth distribution map can be found in [reference needed]. Figure 2 The example shown is in Figure 2 In the example shown, the horizontal axis represents depth, in μm. Figure 2 The left vertical axis represents irradiation damage (dpa), and the right vertical axis represents Cu concentration, meaning that copper ions were used for irradiation.

[0040] S12, nanoindentation tests were performed on the test sample after ion irradiation and the control sample of the test sample to obtain the first load-displacement curve of the test sample and the second load-displacement curve of the control sample.

[0041] Specifically, after ionizing the test sample, nanoindentation tests were performed on the test sample and the control sample of the test sample.

[0042] To perform nanoindentation testing, it is necessary to select an indenter. A spherical indenter with a larger radius can be selected to conduct subsequent nanoindentation testing, thus avoiding the discrete elastoplastic transition caused by dislocation source activation, i.e., the load-displacement jump phenomenon.

[0043] Furthermore, the indenter and load frame compliance of the spherical indenter nanoindenter are calibrated to obtain the displacement of the nanoindenter and the effective radius of the indenter due to the load frame compliance when performing the above-mentioned nanoindentation test. The aforementioned load frame is the load frame of the nanoindenter, including the device for applying the load to the nanoindenter.

[0044] Finally, nanoindentation tests were performed on the irradiated test samples and the unirradiated control samples using a continuous stiffness measurement mode to obtain accurate first load-displacement curves and second load-displacement curves. Specific results can be found in [reference needed]. Figure 3 The example shown is in Figure 3 In the diagram, squares represent no irradiation, meaning the line formed by squares is the second load-displacement curve mentioned above, and circles represent irradiation, meaning the line formed by circles is the first load-displacement curve mentioned above. Figure 3 In the figure, the horizontal axis represents the indentation depth in nm, and the vertical axis represents the load in mN.

[0045] S13, obtain the first simulated load-displacement curve based on the first load-displacement curve, and obtain the second simulated load-displacement curve based on the second load-displacement curve.

[0046] In one specific embodiment, obtaining a first simulated load-displacement curve based on a first load-displacement curve includes: selecting a first preset number of first data points from the elastic portion of the first load-displacement curve, and obtaining a third load and a first indentation depth based on the first data points; obtaining a first effective Young's modulus based on the third load and the first indentation depth; and obtaining a first simulated load-displacement curve based on the first effective Young's modulus.

[0047] The elastic portion of the first load-displacement curve can be determined using the following method:

[0048] First, take the logarithm of the x-axis and y-axis of the first load displacement curve to obtain the logarithmic value of the first x-axis and the logarithmic value of the first y-axis. Then, based on the logarithmic values ​​of the first x-axis and the first y-axis, obtain the first logarithmic curve.

[0049] The above-mentioned logarithmic transformation of the abscissa and ordinate of the first load displacement curve can be achieved by selecting multiple points on the first load displacement curve. For each point, the abscissa is the indentation depth and the ordinate is the load. Assuming that the symbol h represents the indentation depth corresponding to the point and the symbol P represents the load corresponding to the point, the logarithmic value of the first ordinate corresponding to the point is logP and the logarithmic value of the first abscissa corresponding to the point is logh.

[0050] After obtaining the corresponding first logarithmic value of the abscissa and the first logarithmic value of the ordinate for each point, the first logarithmic value of the abscissa is used as the new abscissa, and the first logarithmic value of the ordinate is used as the new ordinate, resulting in the first logarithmic curve. For example, a point in a preset logarithmic coordinate system can be obtained based on each corresponding first logarithmic value of the abscissa and the first logarithmic value of the ordinate, thereby transforming the point selected from the first load-displacement curve to this logarithmic coordinate system. After transforming multiple points selected from the first load-displacement curve to this logarithmic coordinate system, the first logarithmic curve is plotted in this logarithmic coordinate system.

[0051] After obtaining the first logarithmic curve, the slope of the first logarithmic curve is obtained, and the portion of the first logarithmic curve whose slope falls within a first preset slope range is obtained, thus obtaining the first part of the curve. The first preset slope range can be 1.45 to 1.55.

[0052] After obtaining the first part of the curve, the part of the first load-displacement curve that corresponds to the first part of the curve is obtained to obtain the second part of the curve, thereby obtaining the elastic part of the first load-displacement curve.

[0053] Alternatively, the elastic portion of the first load displacement curve can also be obtained by the following method: obtaining the portion of the first load displacement curve whose slope is proportional to the first half of the horizontal axis or whose slope divided by the third power of the vertical axis is a constant, thus obtaining the elastic portion of the first load displacement curve.

[0054] Specifically, after obtaining the first load-displacement curve, the relationship between the first parameter and the second parameter in the first load-displacement curve can be obtained.

[0055] When the first parameter is the slope of the first load-displacement curve and the second parameter is the half-power of the abscissa of the first load-displacement curve, the elastic part of the first load-displacement curve is the part of the first load-displacement curve where the first parameter and the second parameter are proportional.

[0056] When the first parameter is the slope of the first load-displacement curve and the second parameter is the third power of the ordinate of the first load-displacement curve, the elastic part of the first load-displacement curve is the part where the division of the first parameter and the second parameter on the first load-displacement curve results in a constant.

[0057] Alternatively, the elastic portion of the first load-displacement curve can also be obtained as follows: During the nanoindentation test, when the indenter is pressed into multiple preset depths, a small amount of unloading is performed. If the unloading process is completely reversible, it indicates that no plasticity has occurred at the current indentation depth. If there is a residual depth after unloading, it indicates that plasticity has occurred at that indentation depth. Thus, the indentation depth corresponding to the elastic region can be obtained, and the elastic portion of the first load-displacement curve can be obtained based on this indentation depth.

[0058] Alternatively, the first simulated load-displacement curve obtained from the first load-displacement curve can be achieved using methods such as the indentation work decomposition method and the maximum shear stress criterion.

[0059] After obtaining the elastic portion of the first load displacement curve, the elastic portion is sampled to obtain a first preset number of first data points, such as 150.

[0060] Therefore, the first preset number of first data points can be all located in the elastic part of the first load-displacement curve, thereby achieving the first simulated load-displacement curve by fitting based on the elastic part of the first load-displacement curve, avoiding errors in the fitting result caused by including the plastic part of the first load-displacement curve in the fitting, which would lead to errors in the final radiation hardening coefficient calculation result.

[0061] The method for obtaining the third load and the first indentation depth can be as follows: for each first data point, the abscissa of the first data point is taken as the first indentation depth corresponding to the first data point, and the ordinate of the first data point is taken as the third load corresponding to the first data point.

[0062] The method for obtaining the third elastic penetration depth can be as follows: subtract the displacement caused by the load frame compliance of the nanoindenter used in the nanoindentation test from the first indentation depth to obtain the third elastic penetration depth.

[0063] Furthermore, the first effective radius of the contact area between the indenter and the test sample during nanoindentation testing and the displacement caused by the load frame compliance were obtained in advance through the aforementioned indenter and load frame compliance calibration. .

[0064] Furthermore, the aforementioned first effective Young's modulus can be obtained by the following formula:

[0065] ,

[0066] in, For the third load, The third elastic penetration depth, The first effective Young's modulus, The first effective radius of the contact area between the indenter and the test sample. ,in, The first indentation depth, The displacement of the nanoindenter used for nanoindentation testing due to the compliance of the load frame.

[0067] Furthermore, since the number of first data points is a first preset number, all of these first preset number of first data points can be substituted into the above calculation formula, and the first effective Young's modulus can be obtained by fitting the calculation results. Therefore, the first preset number of first effective Young's moduli can be obtained. Select one from the options to obtain the first effective Young's modulus used in the final calculation. .

[0068] After obtaining the aforementioned first effective Young's modulus Then, based on the first effective Young's modulus The first simulated load-displacement curve is obtained, and the final first simulated load-displacement curve is shown below:

[0069] ,

[0070] in, The vertical axis represents the first simulated load-displacement curve. is the abscissa of the first simulated load-displacement curve.

[0071] Therefore, it is possible to describe the elastic part of the first load-displacement curve based on Hertz theory, and extrapolate based on the elastic part to obtain the first simulated load-displacement curve in which the entire curve is elastic. This facilitates the subsequent determination of the elastoplastic transition point on the first load-displacement curve based on the first simulated load-displacement curve.

[0072] Optionally, the first preset number of first data points obtained from the first load displacement curve can also be data points selected from a small portion of the data starting from the curve's starting point.

[0073] In one specific embodiment, obtaining the second simulated load-displacement curve based on the second load-displacement curve includes: selecting a second preset number of second data points from the elastic portion of the second load-displacement curve, and obtaining a fourth load and a second indentation depth based on the second data points; obtaining a second effective Young's modulus based on the fourth load and the second indentation depth; and obtaining the second simulated load-displacement curve based on the second effective Young's modulus.

[0074] Specifically, after obtaining the second load-displacement curve, the fourth load and the second indentation depth are obtained based on the second load-displacement curve, and the fourth elastic penetration depth is obtained based on the second indentation depth.

[0075] The method for selecting a second preset number of second data points from the elastic portion of the second load-displacement curve can be referenced to the method for selecting a first preset number of first data points from the elastic portion of the first load-displacement curve. The second preset slope range can be set to be consistent with the first preset slope range, and the second preset number can be set to be consistent with the first preset number.

[0076] The method for obtaining the fourth load and the second indentation depth can be as follows: for each second data point, the abscissa of the second data point is taken as the second indentation depth corresponding to the second data point, and the ordinate of the second data point is taken as the fourth load corresponding to the second data point.

[0077] The above-mentioned method for obtaining the fourth elastic penetration depth can be as follows: subtract the displacement caused by the load frame compliance of the nanoindenter used in the above-mentioned nanoindentation test from the second indentation depth to obtain the fourth elastic penetration depth.

[0078] Furthermore, the second effective radius of the contact portion between the indenter and the control sample during nanoindentation testing of the control sample was obtained in advance through the aforementioned indenter and load frame compliance calibration.

[0079] Furthermore, the aforementioned second effective Young's modulus can be obtained according to the following formula:

[0080] ,

[0081] in, For the fourth load, The second effective Young's modulus, The second effective radius of the contact area between the indenter and the control sample. This represents the fourth elastic penetration depth. ,in, This is the second indentation depth.

[0082] Furthermore, since the number of second data points is the second preset number, that is, the second preset number of second effective Young's moduli can be obtained. Therefore, the second preset number of second effective Young's moduli can be obtained. Select one from the options to obtain the second effective Young's modulus used in the final calculation. .

[0083] After obtaining the aforementioned second effective Young's modulus Then, based on the second effective Young's modulus The second simulated load-displacement curve is obtained, and the final second simulated load-displacement curve is shown below:

[0084] ,

[0085] in, The vertical axis represents the second simulated load-displacement curve. This represents the abscissa of the second simulated load-displacement curve.

[0086] Therefore, it is possible to describe the elastic part of the second load-displacement curve based on Hertz theory, and extrapolate based on the elastic part to obtain the second simulated load-displacement curve in which the entire curve is elastic. This facilitates the subsequent determination of the elastoplastic transition point on the second load-displacement curve based on the second simulated load-displacement curve.

[0087] For specific results, please refer to Figure 3 The example shown is in Figure 3 In the diagram, the dashed line that partially overlaps with the second load displacement curve is the second simulated load displacement curve, and the dashed line that partially overlaps with the first load displacement curve is the first simulated load displacement curve.

[0088] S14. Obtain the first elastic-plastic transition point based on the first load-displacement curve and the first simulated load-displacement curve, and obtain the second elastic-plastic transition point based on the second load-displacement curve and the second simulated load-displacement curve.

[0089] In one specific embodiment, obtaining the first elastoplastic transition point based on the first load displacement curve and the first simulated load displacement curve includes: obtaining the first target point with the largest abscissa among the points on the first load displacement curve and the first simulated load displacement curve where both the abscissa and ordinate are equal, i.e., the point where the first simulated load displacement curve deviates from the first load displacement curve, and taking the first target point as the first elastoplastic transition point.

[0090] The above-mentioned determination of the second elastic-plastic transition point of the second simulated load-displacement curve based on the second load-displacement curve includes: obtaining the second target point with the largest abscissa among the points on the second load-displacement curve and the second simulated load-displacement curve where both the abscissa and ordinate are equal, that is, the point where the second simulated load-displacement curve deviates from the second load-displacement curve, and taking the second target point as the second elastic-plastic transition point.

[0091] S15, the radiation hardening coefficient is obtained based on the first elastic-plastic transition point, the second elastic-plastic transition point, and the irradiation damage depth distribution map.

[0092] In one specific embodiment, the above-mentioned method of obtaining the radiation hardening coefficient based on the first elastic-plastic transition point, the second elastic-plastic transition point, and the irradiation damage depth distribution map includes: obtaining the first elastic penetration depth of the first load and the indenter corresponding to the first elastic-plastic transition point, and obtaining the second elastic penetration depth of the second load and the indenter corresponding to the second elastic-plastic transition point; obtaining the first critical shear stress based on the first load and the first elastic penetration depth, and obtaining the second critical shear stress based on the second load and the second elastic penetration depth; and obtaining the radiation hardening coefficient based on the first critical shear stress, the second critical shear stress, and the irradiation damage depth distribution map.

[0093] Specifically, since the first elastic-plastic transition point and the second elastic-plastic transition point are obtained according to... Figure 3 The load-displacement curve shown indicates that, therefore, after obtaining the first elastic-plastic transition point, the first elastic-plastic transition point is at... Figure 3 The vertical axis in the figure represents the first load mentioned above, and is based on the first elastic-plastic transition point at... Figure 3 The x-axis in the graph gives the first elastic penetration depth. Similarly, after obtaining the second elastic-plastic transition point, the second elastic-plastic transition point is located at... Figure 3 The vertical axis in the figure represents the second load mentioned above, and is based on the second elastic-plastic transition point at... Figure 3 The horizontal coordinate in the figure gives the second elastic penetration depth mentioned above.

[0094] Furthermore, the first critical shear stress and the second critical shear stress can be obtained according to the following formula:

[0095] ,

[0096] ,

[0097] in, This refers to the first critical shear stress mentioned above. Let P1 be the first load and P2 be the second load, where P1 is the second critical shear stress. The first elastic penetration depth, This represents the second elastic penetration depth.

[0098] Optionally, the above-mentioned method of obtaining the radiation hardening coefficient based on the first critical shear stress, the second critical shear stress, and the irradiation damage depth distribution map includes: obtaining the critical shear stress change based on the first critical shear stress and the second critical shear stress, and obtaining the first irradiation damage of the test sample based on the irradiation damage depth distribution map; and obtaining the radiation hardening coefficient based on the critical shear stress change and the first irradiation damage.

[0099] Specifically, after obtaining the first critical shear stress and the second critical shear stress, the change in critical shear stress can be obtained according to the following formula:

[0100] ,

[0101] in, This represents the change in critical shear stress.

[0102] In one specific embodiment, obtaining the first irradiation damage of the test sample based on the irradiation damage depth distribution map includes: obtaining the depth of the elastoplastic transition of the test sample after ion irradiation; and substituting the depth of the elastoplastic transition into the irradiation damage depth distribution map to obtain the first irradiation damage.

[0103] As an example, the aforementioned elastoplastic transition depth can be expressed as 0.48a, where a is the contact radius. The specific calculation method for a is to multiply the aforementioned first elastic penetration depth by the aforementioned first effective radius, and then take the square root of the result to obtain the contact radius a. Furthermore, the elastoplastic transition depth 0.48a can also be compared with the aforementioned critical shear stress. The results of the association can be found in [link to relevant documentation]. Figure 4 The example shown, Figure 4 The horizontal axis represents the depth of the elastoplastic transition, measured in nm, while the vertical axis represents the change in critical shear stress, measured in GPa.

[0104] After obtaining 0.48a, you can substitute this 0.48a into... Figure 2 The radiation damage depth distribution map shown gives the corresponding radiation damage dpa, which is the first radiation damage dpa1.

[0105] Moreover, after obtaining the critical shear stress change... After the first irradiation damage dpa1, the irradiation hardening coefficient can be obtained.

[0106] The change in hardness can be obtained first using the following formula:

[0107] ,

[0108] in, This represents the change in hardness.

[0109] Obtain the change in hardness After the first irradiation damage dpa1, the irradiation hardening coefficient can be obtained according to the following formula:

[0110] ,

[0111] Where K is the irradiation hardening coefficient and dpa1 is the first irradiation damage.

[0112] In summary, the radiation hardening coefficient generation method of this invention involves ion irradiating a test sample and obtaining an irradiation damage depth distribution map of the test sample based on the irradiation parameters; performing nanoindentation tests on the ion-irradiated test sample and a control sample to obtain a first load-displacement curve for the test sample and a second load-displacement curve for the control sample; obtaining a first simulated load-displacement curve based on the first load-displacement curve and a second simulated load-displacement curve based on the second load-displacement curve; obtaining a first elastoplastic transition point based on the first load-displacement curve and the first simulated load-displacement curve, and obtaining a second elastoplastic transition point based on the second load-displacement curve and the second simulated load-displacement curve; and obtaining the radiation hardening coefficient based on the first elastoplastic transition point, the second elastoplastic transition point, and the irradiation damage depth distribution map. This allows for a quantitative assessment of radiation hardening.

[0113] Furthermore, this invention proposes a method for evaluating irradiation hardening.

[0114] Figure 5 This is a flowchart of the irradiation hardening evaluation method according to an embodiment of the present invention.

[0115] like Figure 5 As shown, the irradiation hardening assessment method includes:

[0116] S51, Obtain the second radiation damage to the item to be evaluated.

[0117] S52, the radiation hardening assessment results of the article to be evaluated are obtained based on the second irradiation damage and the irradiation hardening coefficient.

[0118] Wherein, the irradiation hardening coefficient is a coefficient generated according to the irradiation hardening coefficient generation method of the above embodiments.

[0119] In some embodiments of the present invention, the radiation hardening evaluation results are obtained according to the following formula:

[0120]

[0121] in, This represents the radiation hardening assessment result, where K is the radiation hardening coefficient. This is the second type of irradiation damage.

[0122] The following is combined with Figure 6 The specific embodiments shown will be described in detail.

[0123] Step 1: Perform ion irradiation and calculate the depth distribution spectrum of irradiation damage dpa.

[0124] Specifically, in step 1, the single-crystal tungsten is subjected to ion irradiation. 6MeVCu irradiation was performed. 3+ Ion irradiation, flux 1.06 × 10⁻⁶ 14atoms / cm 2 An area of ​​approximately 10 × 10 mm² on the surface of the sample (i.e., the aforementioned single-crystal tungsten) was scanned using a 2 mm ion beam to form a uniform lateral distribution.

[0125] The single-crystal tungsten irradiated with ions in step 1 is the aforementioned test sample.

[0126] In step 1, the ion irradiation parameters are input into the SRIM software for calculation to obtain the depth distribution of the irradiation damage dpa. This depth distribution of the irradiation damage dpa is the aforementioned irradiation damage depth distribution map. Subsequently, the first irradiation damage dpa1 can be obtained by querying the depth distribution of this irradiation damage dpa.

[0127] Step 2: Perform nanoindentation tests with a spherical indenter on irradiated and unirradiated samples.

[0128] Specifically, in step 2, the irradiated sample is the single-crystal tungsten that underwent ion irradiation in step 1, and the unirradiated sample is the unirradiated single-crystal tungsten, which is the control sample mentioned above.

[0129] In step 2, nanoindentation tests were performed on unirradiated and ion-irradiated single-crystal tungsten. A spherical indenter was selected, and a larger radius (e.g., 56.22 μm) indenter was chosen to avoid discrete elastoplastic transitions controlled by dislocation sources.

[0130] Specifically, in step 2, the compliance of the indenter and load frame was calibrated.

[0131] Specifically, in step 2, a calibrated spherical indenter nanoindenter is used to perform continuous stiffness measurement to obtain the first load-displacement curve and the second load-displacement curve.

[0132] Step 3: Fit the load curves of irradiated and unirradiated samples.

[0133] In step 3, Hertzian theory is used to describe the elastic region data points of the load-displacement curves of unirradiated and ion-irradiated single-crystal tungsten, and the fitting results are extrapolated to deeper regions.

[0134] Specifically, in step 3, the fitted load-displacement curve is the load-displacement curve measured by nanoindentation in step 2, which includes the elastoplastic transition.

[0135] Specifically, in step 3, based on the elastic loading stage (first 150 data points) of the first load-displacement curve and the yield load-displacement curve mentioned above, the first effective Young's modulus is obtained using the following formula. Second effective Young's modulus :

[0136] ,

[0137] ,

[0138] After obtaining the first effective Young's modulus Second effective Young's modulus Then, based on the first effective Young's modulus Second effective Young's modulus The first simulated load-displacement curve and the second simulated load-displacement curve are obtained. This allows for the fitting of load curves for irradiated and unirradiated samples.

[0139] Step 4: Determine the critical shear stress and depth of occurrence for the elastoplastic transition in irradiated and unirradiated samples.

[0140] The elastic-plastic transition point and critical shear stress of unirradiated and ion-irradiated single-crystal tungsten were determined. Specifically, when the simulated load-displacement curve obtained in step 3 deviates from the actual load-displacement curve obtained in step 2, it is considered the elastic-plastic transition point.

[0141] The aforementioned critical shear stress for elastoplastic transition includes the aforementioned first critical shear stress. Second critical shear stress The aforementioned depth is the depth at which the elastoplastic transition occurs, which is 0.48a.

[0142] Step 5: Calculate the irradiation hardening coefficient K .

[0143] After obtaining the critical shear stress change This can be determined based on the change in critical shear stress. The irradiation hardening coefficient K was obtained.

[0144] Moreover, regarding the aforementioned critical shear stress variation Furthermore, multiple measurements can be performed to obtain more accurate measurement data, and then the average critical shear stress can be calculated.

[0145] As an example, if the average is obtained The value is 0.56 GPa, which corresponds to an average depth (0.48 a) of 635 nm for the elastic-plastic transformation of single-crystal tungsten after ion irradiation in step 4. Based on this depth, the irradiation damage depth distribution map in step 1 is consulted to obtain the first irradiation damage dpa1 as 0.15.

[0146] Specifically, in step 5, the average critical shear stress of the elastoplastic transition of unirradiated and ion-irradiated single-crystal tungsten (0.56 GPa) and the dpa1 value of the ion-irradiated single-crystal tungsten at the corresponding average depth (0.48 a) (0.15) are substituted into the above formula to calculate the hardening coefficient. K It is 1.45±0.16 GPa· .

[0147] Step 6: Based on the change in hardness Calculation of the relationship between dpa and hardness change corresponding to different irradiation damage dpa .

[0148] Specifically, in step 6, the irradiation hardening coefficient obtained in step 5 is applied. K According to the following hardness changes The relationship between dpa and irradiation hardness is used to calculate the variation of irradiation hardness at different depths of the irradiated area. :

[0149] ,

[0150] Wherein, the second irradiation damage dpa2 is the specific irradiation damage dpa calculated, and the calculated hardness change This refers to the results of the radiation hardening assessment.

[0151] Actual measurements showed that the radiation hardening coefficient applied in step 6... K Describes the radiation hardening change corresponding to a second irradiation damage dpa2 of 0.02 dpa (uniform damage) in single-crystal tungsten. The average hardness was 1.066 ± 0.12 GPa, which is higher than the average hardness measured by the Burkovich indenter nanoindentation. =1.03±0.39GPa, which is basically consistent with the results, verifying the accuracy and scalability of the method.

[0152] In summary, the radiation hardening assessment method of this invention, by using the radiation hardening coefficient generation method of the above embodiments, can obtain a quantitative assessment result of radiation hardening.

[0153] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein can be considered as a ordered list of executable instructions for implementing logical functions, which can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0154] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0155] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example 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.

[0156] In the description of this specification, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and should not be construed as limiting the present invention.

[0157] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0158] In this specification, unless otherwise stated, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly defined. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0159] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0160] 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 generating an irradiation hardening coefficient, characterized in that, The method includes: The test sample was subjected to ion irradiation, and the irradiation damage depth distribution spectrum of the test sample was simulated based on the ion irradiation parameters. Nanoindentation tests were performed on the test sample after ion irradiation and the control sample of the test sample to obtain the first load-displacement curve of the test sample and the second load-displacement curve of the control sample. A first simulated load-displacement curve is obtained based on the first load-displacement curve, and a second simulated load-displacement curve is obtained based on the second load-displacement curve. The first elastic-plastic transition point is obtained based on the first load-displacement curve and the first simulated load-displacement curve, and the second elastic-plastic transition point is obtained based on the second load-displacement curve and the second simulated load-displacement curve. The radiation hardening coefficient is obtained based on the first elastoplastic transition point, the second elastoplastic transition point, and the irradiation damage depth distribution map; The step of obtaining the first simulated load-displacement curve based on the first load-displacement curve includes: A first preset number of first data points are selected from the elastic portion of the first load-displacement curve, and the third load and the first indentation depth are obtained based on the first data points; The first effective Young's modulus is obtained based on the third load and the first indentation depth; The first simulated load-displacement curve is obtained based on the first effective Young's modulus; The step of obtaining the second simulated load-displacement curve based on the second load-displacement curve includes: A second preset number of second data points are selected from the elastic portion of the second load-displacement curve, and the fourth load and the second indentation depth are obtained based on the second data points; The second effective Young's modulus is obtained based on the fourth load and the second indentation depth; The second simulated load-displacement curve is obtained based on the second effective Young's modulus.

2. The method for generating the irradiation hardening coefficient according to claim 1, characterized in that, The step of obtaining the first elastic-plastic transition point based on the first load-displacement curve and the first simulated load-displacement curve includes: Obtain the first target point with the largest x-coordinate among the points on the first load-displacement curve and the first simulated load-displacement curve where both the x-coordinate and y-coordinate are equal, and take the first target point as the first elastoplastic transition point; The step of obtaining the second elastic-plastic transition point based on the second load-displacement curve and the second simulated load-displacement curve includes: Obtain the second target point with the largest x-coordinate among the points on the second load-displacement curve and the second simulated load-displacement curve where both the x-coordinate and y-coordinate are equal, and use the second target point as the second elastoplastic transition point.

3. The method for generating the irradiation hardening coefficient according to claim 1, characterized in that, The step of obtaining the radiation hardening coefficient based on the first elastoplastic transition point, the second elastoplastic transition point, and the irradiation damage depth distribution map includes: Obtain the first elastic penetration depth of the first load and the indenter corresponding to the first elastic-plastic transition point, and obtain the second elastic penetration depth of the second load and the indenter corresponding to the second elastic-plastic transition point; The first critical shear stress is obtained based on the first load and the first elastic penetration depth, and the second critical shear stress is obtained based on the second load and the second elastic penetration depth. The radiation hardening coefficient is obtained based on the first critical shear stress, the second critical shear stress, and the radiation damage depth distribution map.

4. The method for generating the irradiation hardening coefficient according to claim 3, characterized in that, The step of obtaining the radiation hardening coefficient based on the first critical shear stress, the second critical shear stress, and the irradiation damage depth distribution map includes: The critical shear stress change is obtained based on the first critical shear stress and the second critical shear stress, and the first irradiation damage of the test sample is obtained based on the irradiation damage depth distribution map. The radiation hardening coefficient is obtained based on the change in critical shear stress and the first irradiation damage.

5. The method for generating the irradiation hardening coefficient according to claim 3, characterized in that, The first critical shear stress and the second critical shear stress are obtained according to the following formula: ， ， in, This refers to the first critical shear stress mentioned above. Let P1 be the first load and P2 be the second load, where P1 is the second critical shear stress. This is the first elastic penetration depth. This is the second elastic penetration depth. The first effective radius of the portion of the indenter that contacts the test sample. The second effective radius is the portion of the indenter that contacts the control sample.

6. The method for generating the irradiation hardening coefficient according to claim 4, characterized in that, The first irradiation damage of the test sample obtained based on the irradiation damage depth distribution map includes: The depth of the elastoplastic transition of the test sample after ion irradiation is obtained; Substituting the depth of the elastoplastic transition into the irradiation damage depth distribution map, the first irradiation damage is obtained.

7. The method for generating the irradiation hardening coefficient according to claim 3, characterized in that, The first effective Young's modulus and the second effective Young's modulus are obtained according to the following formula: ， ， in, For the third load, The third elastic penetration depth, This is the first effective Young's modulus. The first effective radius of the portion of the indenter that contacts the test sample. , The depth of the first indentation. The displacement of the nanoindenter used in the aforementioned nanoindentation test due to the compliance of the load frame. For the fourth load, This is the second effective Young's modulus. The second effective radius of the portion of the indenter that contacts the control sample. This represents the fourth elastic penetration depth. , This is the second indentation depth.

8. The method for generating the irradiation hardening coefficient according to claim 4, characterized in that, The radiation hardening coefficient is obtained according to the following formula: ， in, The radiation hardening coefficient is... This is the first type of irradiation damage. This represents the change in hardness. , The change in critical shear stress, i.e. = .

9. A method for evaluating irradiation hardening, characterized in that, The method includes: Obtain the second radiation damage to the item to be evaluated; The radiation hardening assessment result of the article to be evaluated is obtained based on the second radiation damage and radiation hardening coefficient, wherein the radiation hardening coefficient is a coefficient generated by the radiation hardening coefficient generation method according to any one of claims 1-8.

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