A multi-stage in-situ tem stretching device and system based on mechanical driving

Abstract

The application provides a multi-stage in-situ TEM stretching device and system based on mechanical driving, and relates to the field of micro-nano mechanical measurement methods.The multi-stage in-situ TEM stretching device comprises at least two stretching components, the multi-stage stretching components are connected in sequence, and the stretching component of the last stage is used for reducing the displacement loading amount transmitted by the stretching component of the previous stage.By adopting the stretching components with different displacement loading step scaling amounts to be combined, the measurement personnel can accurately measure the mechanical load information of the nano-scale test piece, accurately analyze the internal deformation mechanism of the nano-scale test piece, can realize a large range of displacement loading range, and has the advantages of simple structure and high measurement precision.The stretching device is not only suitable for in-situ stretching measurement of block materials such as metals and ceramics, but also suitable for in-situ stretching test and characterization of mechanical properties of low-dimensional materials such as graphene, molybdenum disulfide, nanowires and nanotubes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of micro-nano mechanics measurement method, and particularly relates to a multi-stage in-situ TEM stretching device and system based on mechanical driving. BACKGROUND

[0002] With the rapid development of micro-nano technology, nano-scale materials and structures have been rapidly developed in various fields, such as microelectronic devices, material synthesis, micro-electro-mechanical sensors, etc. When the size of the material is reduced to the nano scale, due to the increase of the specific surface area, the surface force and the electrostatic force play a leading role, resulting in some physical and chemical effects, and thus some changes in the material structure, so that the material properties at the nano scale are quite different from those at the macro scale. Therefore, it is very important to study the mechanical properties of nano-scale materials and structures. However, from the size, function, manipulation, clamping and loading, the macro mechanical property detection equipment and platform, and the traditional measurement method cannot meet the needs of the nano-scale research object. In-situ transmission electron microscopy provides a good platform for studying material properties. Through the interaction between the electron beam and the sample, the sample area can be magnified by millions of times, and the atomic scale resolution can be achieved, so that the sample can be observed in detail. The sample of the traditional Gatan654 in-situ stretching device is generally thinned in the central circular area. By stretching the macro sample, the evolution process of the material in the central thin area can be observed. However, such stretching method leads to a complex stress state of the material in the thin area, and it is difficult to accurately analyze the nano-scale deformation evolution mechanism of the material.

[0003] At present, the in-situ stretching loading of the transmission electron microscope is mainly through piezoelectric driving loading and V-shaped beam thermal driving loading. The piezoelectric driving method has high precision, but the driving displacement range is small, and the piezoelectric driving method needs to introduce corresponding microelectronic circuits inside the loading rod, which further limits the universal application of this method in in-situ stretching loading. The V-shaped beam thermal driving loading is to make the V-shaped beam expand by resistance heating, and then drive the corresponding displacement of the intermediate mechanism connected thereto. However, this scheme needs to use photolithography to make the corresponding V-shaped driving mechanism, and needs to use ion implantation to introduce resistance into the V-shaped beam. The process is complex and has a certain number of service life restrictions, so this method is too complex and has not been widely used. SUMMARY

[0004] The present application provides a multi-stage in-situ TEM stretching device based on mechanical driving, which solves the problems of small displacement range, complex structure and small application range in the prior art.

[0005] The present application provides a multi-stage in-situ TEM stretching device based on mechanical driving, which solves the problems of small displacement range, complex structure and small application range in the prior art.

[0006] At least two levels of stretching components, displacement loading step size of the at least two levels of stretching components is reduced as the level increases, the multiple levels of the stretching components are connected in sequence, the stretching component of the rear level is used for reducing the displacement loading size transmitted by the stretching component of the front level, and the stretching component of the highest level is connected with the stretching test piece.

[0007] According to the application, a multi-level in-situ TEM stretching device based on mechanical driving is provided, and the stretching device comprises:

[0008] A first-level stretching component, which is provided with a first connecting part and a second connecting part;

[0009] A second-level stretching component, which is provided with a third connecting part and a fourth connecting part, and is connected with the first connecting part and the second connecting part respectively, and the stretching test piece is connected with the third connecting part and the fourth connecting part respectively.

[0010] According to the application, a multi-level in-situ TEM stretching device based on mechanical driving is provided, and the first-level stretching component comprises:

[0011] A first connecting assembly;

[0012] A second connecting assembly, which is connected in series with the first connecting assembly, the rigidity of the second connecting assembly is greater than that of the first connecting assembly, and the first connecting part and the second connecting part are arranged in the second connecting assembly.

[0013] According to the application, a multi-level in-situ TEM stretching device based on mechanical driving is provided, and the first connecting assembly comprises:

[0014] A first connecting part main body, which is provided with a positioning part at a first end and a first notch at a second end;

[0015] A first intermediate connecting part, which is connected with the second connecting assembly at a first end and is located in the first notch at a second end;

[0016] A plurality of first connecting beams, part of the plurality of first connecting beams is located on one side of the first intermediate connecting part, and the remaining part of the plurality of first connecting beams is located on the other side of the first intermediate connecting part, and the second end of the first intermediate connecting part is connected with the side edge of the first notch through the first connecting beams.

[0017] According to the application, a multi-level in-situ TEM stretching device based on mechanical driving is provided, and the plurality of first connecting beams are symmetrically arranged on both sides of the first intermediate connecting part.

[0018] The application provides a multi-stage in-situ TEM stretching device based on mechanical driving, and the second connecting assembly comprises:

[0019] The second connecting member body is provided with a positioning portion at the second end, and a hollow area is arranged at the middle portion of the second connecting member body, and the first connecting portion and the second connecting portion are arranged in the hollow area along the stress direction of the second connecting member body and connected to the two side edges of the hollow area respectively.

[0020] The application provides a multi-stage in-situ TEM stretching device based on mechanical driving, and the second-stage stretching component comprises:

[0021] A third connecting assembly;

[0022] A fourth connecting assembly, and the third connecting assembly and the fourth connecting assembly are arranged at intervals.

[0023] A buffer assembly, and the buffer assembly is connected to the third connecting assembly and the fourth connecting assembly.

[0024] The application provides a multi-stage in-situ TEM stretching device based on mechanical driving, and the buffer assembly comprises a clamping groove and a T-shaped protrusion, the T-shaped protrusion is movably clamped in the clamping groove, one of the clamping groove and the T-shaped protrusion is connected to the third connecting assembly, and the other of the clamping groove and the T-shaped protrusion is connected to the fourth connecting assembly.

[0025] The application provides a multi-stage in-situ TEM stretching device based on mechanical driving, and the third connecting assembly comprises:

[0026] The third connecting member body is provided with a second notch on the side close to the fourth connecting assembly.

[0027] A second intermediate connecting member, the first end of the second intermediate connecting member is connected to the T-shaped protrusion, and the second end of the second intermediate connecting member is located in the second notch.

[0028] A plurality of second connecting beams, a part of the plurality of second connecting beams is located on one side of the second intermediate connecting member, and the remaining part of the plurality of second connecting beams is located on the other side of the second intermediate connecting member, and the second end of the second intermediate connecting member is connected to the side edge of the second notch through the second connecting beams.

[0029] The application provides a multi-stage in-situ TEM stretching device based on mechanical driving, and the plurality of second connecting beams are symmetrically arranged on the two sides of the second intermediate connecting member.

[0030] The application provides a multi-stage in-situ TEM stretching device based on mechanical driving.

[0031] The fourth connecting member body is provided with a third notch on one side close to the third connecting assembly;

[0032] The first measuring connecting member is located in the third notch and connected with the side of the third notch through a plurality of third connecting beams; and the first end of the first measuring connecting member is connected with the clamping groove;

[0033] The second measuring connecting member is located on the side of the first measuring connecting member away from the clamping groove, and is arranged at intervals with the first measuring connecting member; the second measuring connecting member is connected with the side of the third notch through a fourth connecting beam; the third connecting part is arranged at one end of the first measuring connecting member close to the second measuring connecting member, and the fourth connecting part is arranged at one end of the second measuring connecting member close to the first measuring connecting member.

[0034] The plurality of third connecting beams are symmetrically arranged on both sides of the first measuring connecting member.

[0035] The third connecting beams on the same side of the first measuring connecting member are parallel to each other.

[0036] The first measuring connecting member and the second measuring connecting member are arranged on the same straight line at intervals along the stress direction of the second connecting member body.

[0037] The application further provides a multi-stage in-situ TEM stretching system based on mechanical driving, which comprises a loading rod and the multi-stage in-situ TEM stretching device based on mechanical driving.

[0038] The multi-stage in-situ TEM stretching device based on mechanical driving can accurately measure the mechanical load information of a nanoscale sample, accurately analyze the internal deformation mechanism of the nanoscale sample, realize a large-range displacement loading range, and has the advantages of simple structure and high measurement precision. The stretching device is suitable for in-situ stretching measurement of block materials such as metals and ceramics, and is also suitable for in-situ stretching test and characterization of mechanical properties of low-dimensional materials such as graphene, molybdenum disulfide, nanowires and nanotubes. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0040] Figure 1 is a structural schematic diagram of a multi-stage in-situ TEM stretching device based on mechanical driving provided by the present application.

[0041] Figure 2 is a structural schematic diagram of a first stretching component provided by the present application.

[0042] Figure 3 is a structural schematic diagram of a second stretching component provided by the present application.

[0043] Figure 4 is a scanning electron microscope photograph of a multi-stage in-situ TEM stretching device based on mechanical driving provided by the present application.

[0044] Figure 5 is a schematic diagram of the connection relationship of a third connecting part, a fourth connecting part and a stretching test piece provided by the present application.

[0045] Figure 6 is a photograph of a Gatan654 in-situ transmission loading rod provided by the present application.

[0046] Figure 7 is Figure 6 is a local enlarged structural schematic diagram of A in FIG.

[0047] Reference signs:

[0048] 100, a first stretching component; 110, a first connecting part; 120, a second connecting part; 130, a first connecting member main body; 140, a positioning part; 150, a first intermediate connecting member; 160, a first connecting beam; 170, a second connecting member main body; 180, an intermediate connecting part;

[0049] 200, a second stretching component; 210, a third connecting part; 220, a fourth connecting part; 230, a buffer assembly; 231, a clamping groove; 232, a T-shaped protrusion; 240, a third connecting member main body; 250, a second intermediate connecting member; 260, a second connecting beam; 270, a fourth connecting member main body; 280, a first measurement connecting member; 281, a third connecting beam; 290, a second measurement connecting member; 291, a fourth connecting beam;

[0050] 300, a Gatan654 in-situ transmission loading rod;

[0051] 400. Stretching the test specimen. DETAILED DESCRIPTION

[0052] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below with reference to the drawings in the present application. Obviously, the described embodiments are only a part of embodiments of the present application, but not all embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0053] In the description of the embodiments of the present application, it should be noted that the terms “center”, “longitudinal”, “transverse”, “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inner”, “outer” and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the embodiments of the present application. In addition, the terms “first”, “second”, “third” are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0054] In the description of the embodiments of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms “connected” and “connected” should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For a person of ordinary skill in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0055] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is “on” or “under” the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature can be directly above or obliquely above the second feature, or it can only mean that the horizontal height of the first feature is higher than that of the second feature. The first feature can be directly below or obliquely below the second feature, or it can only mean that the horizontal height of the first feature is less than that of the second feature.

[0056] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples without contradiction.

[0057] The specific structure and working principle of the multi-stage in-situ TEM tensile device based on mechanical driving of the present application are described below. Figures 1 to 7 The specific structure and working principle of the multi-stage in-situ TEM tensile device based on mechanical driving of the present application are described below.

[0058] As Figure 1 shown, the multi-stage in-situ TEM tensile device based on mechanical driving includes at least two stages of tensile components, the displacement loading step scaling amount of the at least two stages of tensile components decreases with the increase of the stage, that is, the displacement loading step scaling amount of the previous stage of tensile component is greater than that of the subsequent stage of tensile component, the multi-stage tensile components are connected in turn, the tensile component of the subsequent stage is used to reduce the displacement loading amount transmitted by the tensile component of the previous stage, and the highest stage of tensile component is connected with the tensile test piece 400.

[0059] It should be noted that the present application uses "stage" to limit the tensile component, which is only to distinguish the different displacement loading step scaling amounts of each tensile component, and has no substantial meaning.

[0060] The multi-stage in-situ TEM tensile device based on mechanical driving provided by the present application can accurately measure the mechanical load information of the nanoscale test piece, accurately analyze the internal deformation mechanism of the nanoscale test piece, and realize a wide range of displacement loading range by combining at least two stages of tensile components with different displacement loading step scaling amounts, which has the advantages of simple structure and high measurement precision. The tensile device of the present application is not only suitable for in-situ tensile measurement of bulk materials such as metals and ceramics, but also suitable for in-situ tensile testing and characterization of mechanical properties of low-dimensional materials such as graphene, molybdenum disulfide, nanowires and nanotubes.

[0061] In one embodiment of the present application, as Figure 1 and Figure 2As shown, the stretching device includes a first stretching component 100 and a second stretching component 200, the first stretching component 100 is provided with a first connecting part 110 and a second connecting part 120; the second stretching component 200 is provided with a third connecting part 210 and a fourth connecting part 220, the second stretching component 200 is connected with the first connecting part 110 and the second connecting part 120 respectively, and the stretching test piece 400 is connected with the third connecting part 210 and the fourth connecting part 220 respectively. When the first stretching component 100 is subjected to the displacement load applied by the loading device, the first stretching component 100 deforms in the elastic range after being stressed, and the displacement load is reduced and transmitted to the second stretching component 200, and the second stretching component 200 deforms in the elastic range after being stressed, and the displacement load is reduced and transmitted to the stretching test piece 400. Of course, the number of levels of the stretching component is not limited to two levels, and can be three levels, four levels or more levels, which is determined according to the measurement accuracy requirement, and the more the number of levels of the stretching component, the higher the measurement accuracy.

[0062] In an embodiment of the present application, the first stretching component 100 includes a first connecting assembly and a second connecting assembly, the second connecting assembly is connected in series with the first connecting assembly, the rigidity of the second connecting assembly is greater than that of the first connecting assembly, and the first connecting part 110 and the second connecting part 120 are arranged in the second connecting assembly. Since the rigidity of the second connecting assembly is greater than that of the first connecting assembly, the deformation amount of the second connecting assembly is smaller than that of the first connecting assembly when subjected to the displacement load.

[0063] In an embodiment of the present application, the first connecting assembly includes a first connecting member body 130, a first intermediate connecting member 150 and a plurality of first connecting beams 160, the first connecting member body 130 mainly plays a connecting role, is used for connecting with the Gatan 654 in-situ transmission loading rod 300 through a positioning part, and a first end of the first connecting member body 130 is provided with a positioning part 140. In the embodiment, the positioning part 140 of the first connecting member body 130 is a circular threaded hole, and of course, can also be a positioning protrusion or other positioning structure. When installed, the first connecting member body 130 is installed in the Gatan 654 in-situ transmission loading rod 300 through the circular threaded hole. A second end of the first connecting member body 130 is provided with a first notch to provide space for the first intermediate connecting member 150 and the first connecting beams 160.

[0064] A first end of the first intermediate connecting member 150 is connected with the second connecting assembly, and a second end of the first intermediate connecting member 150 is located in the first notch. The first intermediate connecting member 150 is in a strip-shaped structure, and the first intermediate connecting member 150 is arranged along the stress direction of the second connecting member body 170, that is, arranged along the left-right direction in the figure. Figure 2

[0065] ​The first connecting beams 160 are in a strip structure or a sheet structure, and are used to connect the first intermediate connecting piece 150 and the first connecting piece body 130 together. Part of the plurality of first connecting beams 160 is located on one side of the first intermediate connecting piece 150, and the remaining part of the plurality of first connecting beams 160 is located on the other side of the first intermediate connecting piece 150. The second end of the first intermediate connecting piece 150 is connected to the two side edges opposite to the first notch through the first connecting beams 160. Since the first connecting beams 160 have small rigidity, when subjected to displacement loading, the first connecting beams 160 have a large deformation amount.

[0066] In an embodiment of the present application, the plurality of first connecting beams 160 are symmetrically arranged on both sides of the first intermediate connecting piece 150. Specifically, as shown in FIG. 1, one side of the first intermediate connecting piece 150 is provided with three first connecting beams 160, and the other side of the first intermediate connecting piece 150 is provided with three first connecting beams 160. The three first connecting beams 160 on one side of the first intermediate connecting piece 150 are symmetrically arranged with the three first connecting beams 160 on the other side of the first intermediate connecting piece 150. Figure 2

[0067] In an embodiment of the present application, the second connecting assembly includes a second connecting piece body 170. The first end of the second connecting piece body 170 is connected to the first end of the first intermediate connecting piece 150, and the second end of the second connecting piece body 170 is provided with a positioning portion 140. In the present embodiment, the positioning portion 140 of the second connecting piece body 170 is a circular threaded hole. Of course, it can also be a positioning protrusion or other positioning structure. During installation, the second connecting piece body 170 is installed in the Gatan 654 in-situ transmission loading rod 300 through the circular threaded hole.

[0068] The middle part of the second connecting piece body 170 is provided with a hollow area, which is a rectangular area. Of course, it can also be other shapes. By providing the hollow area in the middle part of the second connecting piece body 170, two intermediate connecting portions 180 with small width are formed on both sides of the hollow area. The rigidity of the intermediate connecting portions 180 is greater than that of the first connecting beams 160. When subjected to displacement loading, the intermediate connecting portions 180 have a small deformation amount, so as to reduce the displacement loading transmitted to the secondary stretching component 200. In the present embodiment, the intermediate connecting portions 180 are provided with two, and the sizes of the two intermediate connecting portions 180 are equal and symmetrically arranged, so as to facilitate subsequent calculation.

[0069] ​The first connecting part 110 and the second connecting part 120 are used for connecting the secondary stretching part 200, the first connecting part 110 and the second connecting part 120 are arranged in the hollow area along the stress direction of the second connecting body 170 and are connected with the two opposite sides of the hollow area respectively. When installed, the secondary stretching part 200 is bonded with the first connecting part 110 and the second connecting part 120 by using high-strength glue.

[0070] It should be noted that the first connecting body 130, the first intermediate connecting body 150, the first connecting beam 160, the second connecting body 170, the first connecting part 110 and the second connecting part 120 in the embodiment are integrated structures, not separate components, that is, the primary stretching part 100 is an integrated structure, and the above components are processed and etched by femtosecond laser only for the convenience of describing the structure.

[0071] In a preferred embodiment of the application, in order to meet the specimen size requirement of the Gatan 654 in-situ transmission loading rod 300, the length of the primary stretching part 100 is 11.7 mm, the width of the primary stretching part 100 is 2.5 mm, and the thickness of the primary stretching part 100 is 100 μm. As shown in Figure 2 In the embodiment, the primary stretching part 100 is made of tungsten material with a thickness of 100 μm and is processed by femtosecond laser etching, the primary stretching part 100 is provided with a circular threaded hole at each end, and the primary stretching part 100 is fixed at the front end of the Gatan 654 in-situ transmission loading rod 300 through the two circular threaded holes.

[0072] In an embodiment of the application, the secondary stretching part 200 comprises a third connecting assembly, a fourth connecting assembly and a buffer assembly 230, the third connecting assembly and the fourth connecting assembly are arranged in the length direction of the secondary stretching part 200, of course, in some embodiments, the third connecting assembly and the fourth connecting assembly can also be connected through a connecting piece with smaller rigidity, and the rigidity of the connecting piece is smaller than the rigidity of the second connecting beam 260. The buffer assembly 230 is connected with the third connecting assembly and the fourth connecting assembly, by arranging the buffer assembly 230 between the third connecting assembly and the fourth connecting assembly, the connection effect and the buffering effect can be achieved, and the damage of the stretching specimen 400 before loading due to vibration can be prevented.

[0073] In an embodiment of the application, the buffer assembly 230 comprises a clamping groove 231 and a T-shaped protrusion 232, the cross section of the clamping groove 231 is in the shape of U, of course, it can also be in the shape of C or other shapes. The T-shaped protrusion 232 is movably clamped in the clamping groove 231, one of the clamping groove 231 and the T-shaped protrusion 232 is connected with the third connecting assembly, and the other of the clamping groove 231 and the T-shaped protrusion 232 is connected with the fourth connecting assembly.

[0074] In one embodiment of the present application, as shown in Figure 3 and Figure 4 , the third connecting assembly comprises a third connecting body 240, a second intermediate connecting piece 250 and a plurality of second connecting beams 260. The third connecting body 240 is provided with a second notch on the side close to the fourth connecting assembly. The second intermediate connecting piece 250 is in a strip structure, and is arranged along the stress direction of the second connecting body 170, i.e. along the left-right direction in Figure 3 . The first end of the second intermediate connecting piece 250 is connected with the T-shaped protrusion 232, and the second end of the second intermediate connecting piece 250 is located in the second notch and is spaced apart from the third connecting body 240 by a certain distance.

[0075] Part of the plurality of second connecting beams 260 is located on one side of the second intermediate connecting piece 250, and the remaining part of the plurality of second connecting beams 260 is located on the other side of the second intermediate connecting piece 250. The second end of the second intermediate connecting piece 250 is connected with the two side edges of the second notch through the second connecting beams 260. The second intermediate connecting piece 250 and the second connecting beams 260 cooperate to form a load buffer beam, which can further prevent the test specimen 400 from being damaged due to vibration before loading.

[0076] In one embodiment of the present application, the plurality of second connecting beams 260 are symmetrically arranged on both sides of the second intermediate connecting piece 250. Specifically, as shown in Figure 3 , two second connecting beams 260 are arranged on one side of the second intermediate connecting piece 250, and two second connecting beams 260 are arranged on the other side of the second intermediate connecting piece 250. The two second connecting beams 260 on one side of the second intermediate connecting piece 250 are symmetrically arranged with the two second connecting beams 260 on the other side of the second intermediate connecting piece 250. Of course, the number of second connecting beams 260 on each side of the second intermediate connecting piece 250 is not limited to this, and can be determined according to actual needs.

[0077] In one embodiment of the present application, the fourth connecting assembly comprises a fourth connecting body 270, a first measuring connecting piece 280 and a second measuring connecting piece 290. The fourth connecting body 270 is provided with a third notch on the side close to the third connecting assembly. The first measuring connecting piece 280 is in a strip structure, and is arranged along the stress direction of the second connecting body 170, i.e. along the left-right direction in Figure 3 . The first measuring connecting piece 280 is located in the third notch and is connected with the two side edges of the third notch through a plurality of third connecting beams 281. The first end of the first measuring connecting piece 280 is connected with the clamping groove 231.

[0078] The second measurement connecting piece 290 is in a strip structure, and is arranged along the stress direction of the second connecting piece main body 170, i.e., along the left-right direction in Figure 3 . The second measurement connecting piece 290 is arranged on the side of the first measurement connecting piece 280 away from the clamping groove 231, and is spaced apart from the first measurement connecting piece 280. Preferably, the width of the first measurement connecting piece 280 is equal to the width of the second measurement connecting piece 290, and the first measurement connecting piece 280 and the second measurement connecting piece 290 are arranged on the same line along the stress direction of the second connecting piece main body 170. The second measurement connecting piece 290 is connected to the two side edges opposite the third notch through the fourth connecting beam 291; the third connecting portion 210 is arranged at one end of the first measurement connecting piece 280 close to the second measurement connecting piece 290, and the fourth connecting portion 220 is arranged at one end of the second measurement connecting piece 290 close to the first measurement connecting piece 280.

[0079] In an embodiment of the present application, the plurality of third connecting beams 281 are symmetrically arranged on both sides of the first measurement connecting piece 280. Two third connecting beams 281 are arranged on one side of the first measurement connecting piece 280, two third connecting beams 281 are arranged on the other side of the first measurement connecting piece 280, and the two third connecting beams 281 on one side of the first measurement connecting piece 280 are symmetrically arranged with the two third connecting beams 281 on the other side of the first measurement connecting piece 280. Of course, the number of third connecting beams 281 on each side of the first measurement connecting piece 280 is not limited to this, and is determined according to actual needs. The third connecting beams 281 on the same side of the first measurement connecting piece 280 are parallel to each other, and the length direction of the first measurement connecting piece 280 is perpendicular to the length direction of the third connecting beams 281.

[0080] It should be noted here that the third connecting piece main body 240, the second intermediate connecting piece 250, the second connecting beam 260, the fourth connecting piece main body 270, the third connecting beam 281, the fourth connecting beam 291, the first measurement connecting piece 280 and the second measurement connecting piece 290 in the present embodiment are all integral structures, and are not separate components, i.e., the two-stage stretching component 200 is an integral structure, and the above components are processed and etched by femtosecond laser only for the convenience of describing the structure.

[0081] In a preferred embodiment of the present application, as shown in Figure 3 , the fourth connecting beams 291 on both sides of the second measurement connecting piece 290 are symmetrically arranged, and the fourth connecting beams 291 are in a strip or sheet structure. One end of the two fourth connecting beams 291 is connected to the two side edges opposite the third notch, i.e., is connected to the upper side edge and the lower side edge of the third notch in Figure 3 , and the other end of the two fourth connecting beams 291 is connected to the two sides of the second measurement connecting piece 290, respectively.

[0082] In one embodiment of the present application, the secondary stretching component 200 is a mechanical load measuring device, the length of the secondary stretching component 200 is 300 μm, the width of the secondary stretching component 200 is 70 μm, the thickness of the secondary stretching component 200 is 10 μm, and the secondary stretching component 200 is processed by femtosecond laser etching. Figure 3 As shown in the figure, the secondary stretching component 200 is composed of two parts, one part (the fourth connecting assembly) is a force beam, and the other part (the third connecting assembly) is a stiffness reduction mechanism. By observing the deflection change of the measuring beam in situ, the mechanical load borne by the test piece can be calculated, and the stiffness reduction mechanism further reduces the external loading displacement, so that the final test piece loading displacement reaches the nanometer level.

[0083] The present application also provides a design method of a multi-stage in-situ TEM stretching device based on mechanical driving. In order to realize quantitative in-situ stretching, the mechanical properties of each structure need to be designed first. Here, the stiffness design method is introduced as an index, and the displacement loading precision is taken as the target for design. The minimum loading step of the Gatan654 in-situ transmission loading rod is 2 μm, and we cannot directly load the loading step to the stretching test piece 400, so we need to scale the loading step through the multi-stage in-situ TEM stretching device designed above. All deformation structures work in the elastic range, so each structure of the multi-stage in-situ TEM stretching device is regarded as a spring structure with certain stiffness. The stiffness design method is adopted to design the stiffness of each structure of the multi-stage in-situ TEM stretching device. represents the stiffness of the first i part structure of the primary stretching component 100, that is, the stiffness of the first intermediate connecting piece 150, the first connecting beam 160, or the intermediate connecting part 180. represents the stiffness of the first i part structure of the secondary stretching component, that is, the stiffness of the second connecting beam 260, the second intermediate connecting piece 250, the first measuring connecting piece 280, the third connecting beam 281, the second measuring connecting piece 290, or the fourth connecting beam 291. As can be seen from the above, the elongation of the intermediate connecting part 180 is the displacement loading amount transmitted to the secondary stretching component 200. The intermediate connecting part 180 of the primary stretching component 100 and the first connecting assembly belong to a series structure, and the two intermediate connecting parts 180 belong to a parallel structure, so the overall stiffness of the primary stretching component is calculated by the following formula (1).

[0084] (1)

[0085] The overall force load of the primary stretching component is calculated by the following formula (2).

[0086] (2)

[0087] wherein, is the total deformation of the primary stretching component 100.

[0088] Further, the deformation of the parallel structure formed by the two intermediate connecting portions 180 is calculated using the following formula (3).

[0089] (3)

[0090] Therefore, it can be seen from the above formula that the stretching displacement amount transmitted by the primary stretching component 100 to the secondary stretching component 200 is determined by the stiffness ratio coefficient, and the larger the stiffness ratio coefficient, the smaller the transmitted displacement amount, so that the displacement loading precision of the multi-stage in-situ TEM stretching device is higher. In the present embodiment, According to the above formula, the corresponding stiffness ratio coefficient can be calculated, and the displacement loading step can be scaled to a precision of 10 nm.

[0091] Next, the displacement scaling effect of the secondary stretching component is calculated. The displacement loading step of the primary stretching component 100 transmitted to the secondary stretching component 200 is 10 nm, and then the displacement loading amount finally transmitted to the stretching specimen 400 is calculated by the following formula (4).

[0092] (4)

[0093] It can be seen from the above formula (4) that the displacement loading amount finally transmitted to the stretching specimen 400 is also modulated by the stiffness ratio coefficient of the secondary stretching component 200, and in the present embodiment, According to the above formula, the stiffness ratio coefficient can be calculated, and the displacement loading step transmitted to the stretching specimen 400 is scaled to 1.67 nm. Therefore, the displacement loading step of the multi-stage in-situ TEM stretching device can reach a loading precision of 1.67 nm.

[0094] In order to prepare the in-situ transmission stretching specimen, different stretching specimen 400 preparation and transfer methods can be selected according to the characteristics of the specimen to be stretched. For general metal and ceramic bulk materials, the FIB sample preparation method is used to extract the corresponding micron-level sample from the bulk, then the corresponding sample is locally thinned, and finally the sample is transferred between the third connecting portion 210 and the fourth connecting portion 220 by a high-precision mechanical hand. The two ends of the sample are fixed on the third connecting portion 210 and the fourth connecting portion 220 respectively by FIB ion beam assisted deposition.

[0095] For example, Figure 5As shown, for low-dimensional materials such as nanowires, the transfer is completed directly under an optical microscope using a robotic arm device. The two ends of the nanowires are fixed to the third connecting part 210 and the fourth connecting part 220 by conductive silver paste or FIB ion beam assisted deposition.

[0096] like Figure 6 and Figure 7 As shown, after transferring the in-situ tensile transmission specimen to a multi-stage in-situ TEM tensile device, the device is then mounted on a Gatan 654 in-situ transmission loading rod 300. During loading, the loading is performed via a motor drive mechanism integrated into the Gatan 654. The minimum loading step of this loading rod is 1 μm. Through scaling via the multi-stage in-situ TEM tensile device, the loading displacement of the tensile specimen 400 can be reduced to nanometer-level precision. By observing and recording the deflection change of the force-measuring beam, the magnitude of the load on the tensile specimen 400 can be measured.

[0097] The multi-stage in-situ TEM tensile apparatus of the present invention is simple to manufacture. The multi-stage loading structure design and the introduction of a buffer device provide excellent protection for ultra-thin tensile specimens 400. It can realize quantitative in-situ tensile deformation testing and load measurement of nanoscale materials at room temperature, achieving a displacement loading step size on the order of 1 nm. It is suitable for in-situ TEM tensile characterization of various nanomaterials.

[0098] The present invention also provides a mechanically driven multi-stage in-situ TEM stretching system, which includes a loading rod and the mechanically driven multi-stage in-situ TEM stretching device described in any of the above embodiments.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-stage in-situ TEM tensile device based on mechanical driving, characterized in that, The application relates to a tensile device. The tensile device comprises: at least two-stage tensile components, the displacement loading step scaling amount of the at least two-stage tensile components decreases with the increase of the stage, the multi-stage tensile components are connected in sequence, the tensile component of a later stage is used for reducing the displacement loading amount transmitted by the tensile component of a former stage, and the tensile component of a highest stage is connected with a tensile test piece (400); the tensile device comprises: a first-stage tensile component (100) provided with a first connecting part (110) and a second connecting part (120); a second-stage tensile component (200) provided with a third connecting part (210) and a fourth connecting part (220), the second-stage tensile component (200) is connected with the first connecting part (110) and the second connecting part (120) respectively, and the tensile test piece (400) is connected with the third connecting part (210) and the fourth connecting part (220) respectively; the first-stage tensile component (100) comprises: a first connecting assembly; a second connecting assembly connected with the first connecting assembly in series, the rigidity of the second connecting assembly is greater than that of the first connecting assembly, and the first connecting part (110) and the second connecting part (120) are arranged on the second connecting assembly; the second-stage tensile component (200) comprises: a third connecting assembly; a fourth connecting assembly, the third connecting assembly and the fourth connecting assembly are arranged in a spaced mode; a buffer assembly (230) connected with the third connecting assembly and the fourth connecting assembly; 2. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 1, wherein, because the rigidity of the second connecting assembly is greater than that of the first connecting assembly, the deformation amount of the second connecting assembly is smaller than that of the first connecting assembly when the displacement loading amount is received; the second-stage tensile component (200) is composed of two parts, one part is a force beam, and the other part is a rigidity reduction mechanism; the deflection change of the beam can be measured by in-situ observation, and the mechanical load received by the test piece can be calculated; the rigidity reduction mechanism further reduces the external loading displacement, so that the final test piece loading displacement reaches the nanometer level. the first connecting assembly comprises: a first connecting piece body (130), a first end of the first connecting piece body (130) is provided with a positioning part (140), and a second end of the first connecting piece body (130) is provided with a first notch; a first intermediate connecting piece (150), a first end of the first intermediate connecting piece (150) is connected with the second connecting assembly, and a second end of the first intermediate connecting piece (150) is located in the first notch; a plurality of first connecting beams (160), part of the plurality of first connecting beams (160) is located on one side of the first intermediate connecting piece (150), and the remaining part of the plurality of first connecting beams (160) is located on the other side of the first intermediate connecting piece (150), and the second end of the first intermediate connecting piece (150) is connected with the side edge of the first notch through the first connecting beams (160).

3. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 2, wherein, The first connecting beams (160) are symmetrically arranged on both sides of the first intermediate connecting piece (150).

4. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 2, wherein, The second connecting assembly comprises: The second connecting piece body (170) is provided with a positioning portion (140) at the second end thereof, and a hollow region is arranged at the middle portion of the second connecting piece body (170), wherein the first connecting portion (110) and the second connecting portion (120) are arranged in the hollow region and connected to the two opposite side edges of the hollow region along the stress direction of the second connecting piece body (170).

5. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 4, wherein, The buffer assembly (230) comprises a clamping groove (231) and a T-shaped protrusion (232), wherein the T-shaped protrusion (232) is movably clamped in the clamping groove (231), one of the clamping groove (231) and the T-shaped protrusion (232) is connected to the third connecting assembly, and the other of the clamping groove (231) and the T-shaped protrusion (232) is connected to the fourth connecting assembly.

6. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 5, wherein, The third connecting assembly comprises: The third connecting piece body (240) is provided with a second notch on the side close to the fourth connecting assembly; The second intermediate connecting piece (250) is connected to the T-shaped protrusion (232) at the first end thereof, and the second end of the second intermediate connecting piece (250) is located in the second notch; The second connecting beams (260) are arranged on both sides of the second intermediate connecting piece (250).

7. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 6, wherein, The second connecting beams (260) are symmetrically arranged on both sides of the second intermediate connecting piece (250).

8. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 5, wherein, The fourth connecting assembly comprises: The fourth connecting piece body (270) is provided with a third notch on the side close to the third connecting assembly; The first measurement connecting piece (280) is located in the third notch and connected to the side edge of the third notch through a plurality of third connecting beams (281); and the first end of the first measurement connecting piece (280) is connected to the clamping groove (231). A second measurement connecting piece (290) is located on the side of the first measurement connecting piece (280) away from the clamping groove (231), and is arranged in a spaced manner with the first measurement connecting piece (280). The second measurement connecting piece (290) is connected with the side of the third notch through a fourth connecting beam (291). The third connecting part (210) is arranged at one end of the first measurement connecting piece (280) close to the second measurement connecting piece (290), and the fourth connecting part (220) is arranged at one end of the second measurement connecting piece (290) close to the first measurement connecting piece (280).

9. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 8, wherein, A plurality of the third connecting beams (281) are arranged in a symmetrical manner on both sides of the first measurement connecting piece (280).

10. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 9, wherein, The third connecting beams (281) on the same side of the first measurement connecting piece (280) are parallel to each other.

11. The multi-stage in-situ TEM tensile device based on mechanical driving according to claim 8, wherein, The first measurement connecting piece (280) and the second measurement connecting piece (290) are arranged in a spaced manner on the same straight line along the stress direction of the second connecting piece main body (170).

12. A multi-stage in-situ TEM tensile system based on mechanical driving, characterized in that, The mechanical drive-based multi-stage in-situ TEM stretching device comprises a loading rod and the mechanical drive-based multi-stage in-situ TEM stretching device according to any one of claims 1 to 11.

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