CN102967507B - A kind of material ions irradiation mechanic property test method - Google Patents

Abstract

The invention provides a method for evaluating the mechanical properties of material ion irradiation. The method includes: first processing a specific irradiated sample, then measuring the actual thickness D1 and the sample width D2 from the bottom of the U-shaped notch to the lower surface of the irradiated sample, and then putting the sample into an ion implanter for further processing. Double-sided irradiation, the irradiated sample is subjected to tensile test and impact test to obtain experimental data, and finally the obtained data is used to evaluate the mechanical properties of the material, and the toughness of the material is evaluated by the impact energy obtained from the impact test. The strength of the material is obtained by the following method: R _m =F/(D1×D2), wherein R _m is the tensile strength of the material, and F is the maximum force reached during the experiment determined on the tensile curve. The invention solves the problem that it is difficult to evaluate the mechanical properties of materials under ion irradiation, and has important scientific research value.

Description

A method for testing the mechanical properties of materials under ion irradiation

technical field

The invention belongs to material mechanics testing technology, in particular to a method for testing the mechanical properties of material ion irradiation, and is especially suitable for testing the mechanical properties of fusion reactor structural materials.

Background technique

Fusion reactor structural materials, such as cladding or first wall structural materials, are subjected to high-energy (14 MeV) and high-dose (10 ²³ n·cm ^-2 ) neutron irradiation released by fusion reactions during service, which will lead to the organization of materials Deterioration, such as: composition segregation, radiation phase transformation, radiation swelling, radiation-induced dislocation ring precipitation, etc. These changes in the structure will eventually lead to the reduction of the mechanical properties of the material such as strength, ductility, toughness and shortened service life. Seriously It endangers the safety performance of fusion reactor operation. Therefore, before the fusion reactor is finally put into commercial application, the research on the performance of material irradiation organization is particularly important. At present, neutron sources at home and abroad are very limited, the energy and dose of neutrons cannot meet the requirements of fusion reactors, and the characteristics of long time-consuming neutron irradiation seriously limit the structure and performance of existing neutron sources for materials research applications. Ion irradiation is similar to neutron irradiation. The initial dislodged atoms produced by collisions are the nuclei of the material itself, which can be used to simulate the effect of neutron irradiation. Therefore, in order to overcome the above-mentioned shortcomings of neutron irradiation, a large number of domestic and foreign Many scientific researchers have used ion irradiation to simulate neutron irradiation to study the law and mechanism of changes in the structure and properties of materials.

Compared with neutron irradiation, there is a significant disadvantage of ion irradiation: the ion penetration ability is very limited, usually only a few hundred nanometers in the material, so the processed standard tensile specimens (such as dimension For: Φ5mm×25mm) or V-shaped or U-shaped impact specimen (for example, the size is: 10mm×10mm×50mm) after ion irradiation, the data obtained from the mechanical performance test are obtained from the same test specimen without irradiation The mechanical data are very close, that is, due to the thickness of the standard tensile or impact specimens, the effect of irradiation on the mechanical properties is difficult to reflect. In a word, the conventional methods for evaluating the mechanical properties of materials are not suitable for the evaluation of the mechanical properties of materials under ion irradiation.

Contents of the invention

The purpose of the present invention is to provide a method for testing the mechanical properties of materials under ion irradiation. The mechanical property data obtained by this method can reflect the impact of ion irradiation on the mechanical properties of materials. This method can solve the problem of difficult evaluation of the mechanical properties of materials under ion irradiation. The mechanical property data obtained by this method can provide guidance for the composition optimization design and preparation process adjustment of advanced fusion reactor structural materials.

A kind of material ion irradiation mechanical property test method provided by the invention, its step comprises:

The first step is to process a U-shaped notch on the sample to be tested;

The width of the upper surface of the sample to be tested is D2, the distance from the bottom of the U-shaped notch to the A surface of the lower surface is D1, and the width of the U-shaped notch is L1; D2=10mm±5mm, D1<0.06mm, L1=0.2mm±0.05 mm;

Step 2 Measure the actual distance d1 from the bottom of the U-shaped notch to the lower surface and the actual width d2 of the upper surface of the sample to be tested;

In step 4, the sample to be tested is subjected to double-sided ion irradiation;

In the fifth step, the mechanical property test is carried out on the sample to be tested after irradiation, and the test data is obtained. The tensile strength of the material after irradiation is R _m =F/(d1×d2), wherein R _m is the tensile strength of the material, F Determine the maximum force achieved during the experiment on the tensile curve graph.

As an improvement of the above technical solution, the length L2 of the sample to be tested is 80 mm±20 mm, and the thickness D3 is 0.3 mm±0.1 mm.

The innovation of the present invention lies in: by opening a small gap on the surface of the irradiated sample, on the one hand, the thickness of the irradiated surface of the material can be reduced to D1 thin, so that the influence of irradiation on the mechanical properties of the material cannot be ignored; on the other hand, , this gap is sensitive and can amplify the effect of irradiation on the mechanical properties of materials, that is to say, compared with unirradiated samples, the mechanical property data of irradiated samples will have obvious differences. By studying the change law of the mechanical properties of materials under irradiation, a scientific reference can be provided for the optimal design of advanced iron and steel material components and the improvement of the preparation process. Therefore, the method provided by the invention has important practical significance.

Description of drawings

Figure 1 is a schematic diagram of the irradiated sample, where (a) is the main view and (b) is the top view.

detailed description

The method for testing the mechanical properties of a material ion irradiation provided by the present invention first measures the actual thickness D1 from the bottom of the U-shaped notch to the lower surface of the sample to be irradiated and the actual width D2 of the sample, and then puts the sample into the ion Double-sided irradiation is carried out in the injection machine, and then the mechanical properties are tested with a universal tensile testing machine or an impact testing machine. The impact energy obtained from the impact test is directly used to evaluate the toughness of the material irradiation, while the strength of the material needs to be calculated. . Its specific steps include:

The first step is to process a U-shaped notch on the sample to be tested. The distance from the bottom of the U-shaped notch to the lower surface A is D1, the width of the U-shaped notch is L1, and the actual size tolerance is less than 5%. Not lower than level 3, and its structure is shown in Figure 1.

The length of the sample is L2, the width is D2, and the thickness is D3. The center of the sample is U-shaped, and the width of the U-shaped notch is L1. The distance between the bottom of the U-shaped notch and the lower surface of the sample is D1 (see Figure 1 for details). The internal oil stains should be cleaned, and the sides should be polished.

Specific dimensions: L1=0.2mm±0.05mm, L2=80mm±20mm, D1: <0.06mm, D2=10mm±5mm, D3=0.3mm±0.1mm

The side of the processed sample to be tested should be polished to facilitate observation under a microscope, and the sample to be tested should be cleaned;

The second step is to actually measure the distance D1 from the bottom of the U-shaped notch to the lower surface and the width D2 of the upper surface, which are recorded as d1 and d2 respectively;

Step 3 Put the above sample into an ion implanter for double-sided ion irradiation.

The fourth step is to test the mechanical properties of the irradiated sample through a universal tensile testing machine or an impact testing machine to obtain test data. The tensile strength R _m of the material after radiation needs to be calculated and the toughness can be evaluated by impact energy. The formula for calculating the tensile strength is: R _m =F/(d1×d2), where R _m is the tensile strength of the material, F is the maximum force reached during the experiment determined on the tensile curve, and d1 is the U-shaped notch bottom to The actual thickness of the lower surface, d2 is the actual measured width of the sample.

The present invention is described in more detail below by means of examples, but the following examples are only illustrative, and the protection scope of the present invention is not limited by these examples.

Example 1:

The quenched + tempered SCRAM steel (0.1wt.%C-9.3%Cr-2.26%WV-Ti-N) independently developed by Huazhong University of Science and Technology was processed into irradiation samples as shown in Figure 1, and the processing quantity was 3, the surface finish level of the 3 samples is 3.1, the side (D3×L1 surface) is polished with fine sandpaper, and then the samples are put into the ultrasonic cleaning tank and cleaned with gasoline for 0.5h, and then replaced with acetone After cleaning for 1 hour, measure the cleaned sample through a microscope. The distances D1 from the bottom of the U-shaped notch to the lower surface of the sample are 0.046mm, 0.052mm, and 0.065mm respectively, and the width D2 of the sample measured by a vernier caliper is 10.01mm. mm, 10.02mm, 9.96mm, then put the sample into the ion implanter for double-sided iron ion irradiation, the irradiation temperature is set at 300°C, and the dose is 5dpa. After the irradiation is completed, take out the sample and pass the universal tensile test machine (model: H3-C3-2.0t-3B-C) to perform a tensile test on it to obtain a tensile curve. From the figure, the maximum force during the experiment is 358.5N, 406.5N, 459.8N, and finally through the formula _Rm =F/(D1×D2) Calculated Rm are 778.6MPa, 780.17MPa, 710.2MPa respectively. When the D1 of the sample is less than 0.06mm, the results are relatively concentrated and have certain credibility.

Example 2:

The quenched + tempered SCRAM steel (0.1wt.%C-9.3%Cr-2.26%W-V-Ti-N) was irradiated as shown in Figure 1, and the number of samples was 3. The smoothness level of the lower surface is 3.2, the side (D3×L1 surface) is polished by sandpaper, and then the sample is put into the ultrasonic cleaning tank and cleaned with gasoline for 1 hour, then replaced with acetone for 0.5 hour, and then cleaned The sample is measured through a microscope. The distance D1 from the bottom of the U-shaped notch to the lower surface of the sample is 0.059mm, 0.054mm, and 0.066mm respectively, and the width D2 of the sample measured by a vernier caliper is 10.00mm, 10.03mm, and 10.04mm, respectively. Then put the sample into the ion implanter for double-sided iron ion irradiation, the irradiation temperature is set at 450°C, and the dose is 10dpa. After the irradiation is completed, take out the sample and pass it through the impact testing machine (model: XJJ-5) The impact test was carried out, and the obtained impact energy was 1.12J, 1.09J, and 1.22J, respectively. When the D1 of the sample is less than 0.06mm, the results are relatively concentrated and have certain credibility.

The above description is only a preferred embodiment of the present invention, but the present invention should not be limited to the content disclosed in this embodiment and the accompanying drawings. Therefore, all equivalents or modifications that do not deviate from the spirit disclosed in the present invention fall within the protection scope of the present invention.

Claims (1)

1. A method for testing the mechanical properties of material ion irradiation, the mechanical property data obtained by the method is used to evaluate the impact of ion irradiation on the mechanical properties of materials, the steps comprising: The first step is to process a U-shaped notch on the sample to be tested to expand the effect of irradiation on the mechanical properties of the material; The sample to be tested is a fusion reactor structure material. The length L2 of the sample to be tested is 80mm±20mm, and the thickness D3 is 0.3mm±0.1mm; the width of the upper surface of the sample to be tested is D2, and the U-shaped notch bottom to the lower surface The distance of surface A is D1, the width of U-shaped notch is L1; D2=10mm±5mm, D1<0.06mm, L1=0.2mm±0.05mm; Step 2 Measure the actual distance d1 from the bottom of the U-shaped notch to the lower surface and the actual width d2 of the upper surface of the sample to be tested; In the third step, double-sided ion irradiation is carried out on the sample to be tested; The fourth step is to test the mechanical properties of the sample to be tested after irradiation, and obtain the test data. The tensile strength of the material after irradiation is R _m = F/(d1×d2), where R _m is the tensile strength of the material, F Determine the maximum force achieved during the experiment on the tensile curve graph.