Micro-nano impact press-in testing device and method based on circulating refrigeration

Abstract

The invention discloses a micro-nano impact press-in testing device and method based on circulating refrigeration, and relates to the technical field of material performance testing, the micro-nano impact press-in testing device comprises a pressing rod and an objective table which are used for low-temperature micro-nano impact press-in testing, and a refrigeration device for refrigerating and cooling the pressing rod and the objective table, the refrigerating device refrigerates the pressing rod and the objective table in an embedded runner mode, a connected cold guide line and a refrigerating balancer making contact with the cold guide line are arranged between the pressing rod and the objective table, and the cold guide line and the refrigerating balancer jointly stabilize the temperature of the pressing rod and the temperature of the objective table at a common temperature point. When a low-temperature micro-nano impact press-in test is carried out, the temperature difference between the sample and the test head due to refrigeration degree difference can be quickly balanced, the influence of temperature drift on the test precision is eliminated, and the accuracy of a low-temperature micro-nano impact press-in test result is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of material performance testing, and specifically to a micro-nano impact indentation testing device and method based on cyclic refrigeration. Background Art

[0002] Impact indentation is an experimental method used to measure the local mechanical properties of materials under high-speed dynamic loads. It is particularly suitable for studying the behavior of materials under high strain rate conditions, such as automobile collisions, space launches, supersonic aircraft, high-speed forming processes, and military protection. The strain rate upper limit of traditional static or quasi-static indentation testing technology is relatively low, usually not exceeding 10 -1 s -1 , which is difficult to meet the evaluation needs of dynamic response. Therefore, impact indentation technology came into being, which can provide a higher strain rate range, usually up to 10 3 s -1 Above, or even higher, to simulate the dynamic load effect under real conditions. Traditional impact indentation technology usually focuses on dynamic mechanical behavior at room temperature or higher temperatures, but under low temperature conditions, the physical and mechanical properties of materials will change significantly, such as increased brittleness and reduced toughness, which is crucial for the application of materials in extreme environments. Accordingly, the present invention aims to provide a fast, efficient, and stable low-temperature loading environment for the micro-nano impact indentation tester, and obtain the service performance of the material under extreme conditions of impact indentation and low-temperature environment coupling.

[0003] In the field of material micromechanical properties testing, many scholars have studied low-temperature static nanoindentation devices and achieved certain results, but there are few studies on low-temperature loading of micro-nano impact indentation test devices. At present, most refrigeration systems for low-temperature nanoindentation are atmosphere refrigeration, which is combined with commercial liquid nitrogen dewar flasks. Large and heavy atmosphere chambers are required, which makes it difficult to integrate multiple in-situ monitoring methods. The requirements for placement site, sample size and energy consumption are very high. In addition, it is often difficult to achieve precise cooling of the indenter and the sample at the same time. The temperature difference between the indenter and the sample will cause "temperature drift" phenomenon, which restricts the test accuracy.

[0004] In summary, in view of the lack of testing methods for the micromechanical behavior of functional materials and structural materials under the coupling of impact indentation and low temperature environment, the construction of service performance conditions of materials under extreme conditions of impact indentation and low temperature environment coupling will contribute to the further development of energy, electricity, aerospace and other fields. Therefore, it is very necessary to design and develop a refrigeration device suitable for micro-nano impact indentation tester that can achieve continuous temperature change, coordinated refrigeration and easy integration with various monitoring methods. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a micro-nano impact intrusion testing device and method based on cyclic refrigeration. By separately cyclically refrigerating the pressure rod and the stage used for the impact intrusion test, accurate observation and research on the microscopic impact mechanical properties of the material under extreme low temperature conditions can be achieved.

[0006] In order to solve at least one of the above technical problems, the technical solution provided by the present invention is:

[0007] A micro-nano impact indentation test device based on cyclic refrigeration is provided, comprising a linear motor, a driving platform, a piezoelectric stack, a pressure rod, an infrared thermal imaging component, a stage, a slide, and a refrigeration device, wherein:

[0008] The driving platform is arranged on the linear motor, and can move toward the stage under the drive of the linear motor; a hinge base is also arranged on the driving platform, and a connected piezoelectric stack and a pressure rod are arranged on the hinge base, and a diamond pressure head is arranged at the tip of the pressure rod, so that the pressure rod and the diamond pressure head can move toward the stage under the push of the piezoelectric stack, and a force sensor is arranged between the pressure rod and the piezoelectric stack to obtain the driving force applied by the piezoelectric stack to the pressure rod;

[0009] The stage is arranged on a slide, and a clamp is arranged on the surface of the stage facing the pressure rod, the clamp can stably clamp the sample to be tested, and the diamond indenter can move to contact the sample to be tested, and the stage can move along the slide to a position where the sample to be tested is directly opposite to the tip of the pressure rod;

[0010] The infrared thermal imaging component is arranged on one side of the pressure rod, and its infrared thermal imaging range includes the force sensor, the pressure rod, the sample to be tested and the stage;

[0011] The refrigeration device is arranged on one side of the pressure rod, and is connected to the pressure rod microchannel buried inside the pressure rod through the pressure rod inlet cold pipe and the pressure rod outlet cold pipe to form a circulation pipeline, so that the refrigeration device can circulate the refrigeration medium inside the pressure rod; the refrigeration device is also connected to the stage microchannel buried inside the stage through the stage inlet cold pipe and the stage outlet cold pipe to form a circulation pipeline, so that the refrigeration device can circulate the refrigeration medium inside the stage;

[0012] A cooling wire is also provided between the pressure rod and the stage, wherein one end of the cooling wire is connected to a position close to the diamond indenter, and the other end is connected to a position on the stage close to the sample to be tested, so that heat exchange can be performed between the pressure rod and the stage through the cooling wire.

[0013] An embodiment of the present invention is that a refrigeration balancer is arranged below the pressure rod, wherein the refrigeration balancer comprises an outer frame, a cold conduction plate, a limit hook, and a cold storage container, the outer frame is a hollow container with at least one set of side openings, at least part of the top surface of which is a cold conduction plate, and a limit hook arranged close to the cold conduction plate is arranged above the top surface, and the limit hook can clamp the cold conduction line on the top surface of the outer frame to keep in contact with the cold conduction plate;

[0014] A cold storage container that completely fills the internal space is detachably provided inside the outer frame. The cold storage container has at least one transparent observation window on one side, and the observation window is located at the side opening of the outer frame. The top of the cold storage container is a cold-conducting top plate. The cold storage container is filled with phase change material, so that the phase change material can pass through the cold-conducting top plate and the cold-conducting plate in turn to perform heat exchange with the cold-conducting line.

[0015] Furthermore, a camera assembly is provided on one side of the refrigeration balancer, and the camera area of ​​the camera assembly includes the entire observation window.

[0016] Furthermore, the cooling wire, the cooling plate and the cooling top plate are made of red copper.

[0017] An embodiment of the present invention is that a pressure rod thermocouple is arranged on the pressure rod near the diamond indenter, and a stage thermocouple is arranged on the stage near the sample to be tested, and the distance between the pressure rod thermocouple and the diamond indenter and the distance between the stage thermocouple and the sample to be tested are both within 0.5 mm.

[0018] An implementation manner of the present invention is that a cold-insulating baffle for preventing low temperature from being conducted to the force sensor is provided between the force sensor and the pressure rod.

[0019] An implementation manner of the present invention is that the surfaces of the pressure rod inlet cold pipe, the pressure rod outlet cold pipe, the loading platform inlet cold pipe, and the loading platform outlet cold pipe are all coated with heat preservation materials.

[0020] An implementation manner of the present invention is that a protective gas channel capable of spraying protective gas toward the hinge base is also provided on the slide.

[0021] An implementation manner of the present invention is that the slide is an upper and lower single-degree-of-freedom slide.

[0022] In addition, the present invention also provides a micro-nano impact indentation test method based on cyclic refrigeration, which uses the above device to perform the test, and includes the following steps:

[0023] Step S1: assembling the refrigeration pipeline according to the device, fixing the sample to be tested on the stage, installing the diamond indenter on the pressure rod, and adjusting the stage and the pressure rod so that the position of the diamond indenter corresponds to the position of the sample to be tested;

[0024] Step S2: The cooling wire is clamped in the limit hook of the refrigeration balancer to keep it in contact with the cooling plate, and the phase change material corresponding to the experimental temperature is filled in the cold storage container according to the experimental requirements, and the phase change material is pre-cooled at the experimental temperature;

[0025] Step S3: outputting the protective gas through the protective gas channel, setting the infrared thermal imaging component and the camera component to a working state, starting the refrigeration device to cyclically cool the pressure head and the stage respectively until the experimental temperature is reached, and placing the cold storage container filled with the pre-cold phase change material in the refrigeration balancer;

[0026] Step S4: After observing that the indenter and the stage are stable at the experimental temperature, control the drive platform and piezoelectric stack and other components to perform a low-temperature impact indentation experiment, and collect relevant data of the impact indentation experiment.

[0027] The technical effects of the present invention are:

[0028] 1. The present invention can implement micro-nano impact indentation test under low temperature conditions. It adopts an embedded microfluidic channel to cool the test sample and the test head at the same time. At the same time, a cooling wire in contact with a cooling balancer is arranged between the sample and the test head. The cooling balancer and the cooling wire at the experimental temperature can be used to implement two-way cooling between the sample and the test head, so that the temperature between the sample and the test head can be stably maintained at the experimental temperature, thereby quickly balancing the temperature difference between the sample and the test head due to the difference in cooling degree, eliminating the influence of temperature drift on the test accuracy, and making the test results more representative.

[0029] 2. The present invention can adjust the output power of the refrigeration device in real time according to the information fed back by the thermocouple and the thermal imaging component to achieve continuous temperature adjustment. The entire experimental device has a simple structure and a compact layout. It does not require an atmosphere refrigeration chamber and has a high degree of integration. It provides effective support for revealing the microscopic failure mechanism of materials under low-temperature impact conditions and the law of their performance evolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 is an axonometric schematic diagram of the present invention as a whole;

[0032] Figure 2 It is an axonometric schematic diagram of the compression rod part of the present invention;

[0033] Figure 3 It is an axonometric schematic diagram of the stage portion of the present invention;

[0034] Figure 4 is an axonometric schematic diagram of a refrigeration balancer in the present invention;

[0035] Figure 5 is a cross-sectional view of a refrigeration balancer in the present invention;

[0036] Figure 6 is a perspective view of the pressure rod of the present invention;

[0037] Figure 7 is a cross-sectional view of the pressure rod of the present invention;

[0038] Figure 8 is a perspective view of the stage of the present invention;

[0039] Fig. 9 is a cross-sectional view of the stage of the present invention;

[0040] In the figure, 1-linear motor, 2-driving platform, 3-hinge base, 4-piezoelectric stack, 5-force sensor, 6-cold insulation baffle, 7-pressure rod microchannel, 71-pressure rod inlet cold pipe, 72-pressure rod outlet cold pipe, 8-pressure rod, 9-pressure rod thermocouple, 10-diamond indenter, 11-infrared thermal imaging component, 12-cooling wire, 13-stage thermocouple, 14-sample to be tested, 15-fixture, 16 -protective gas channel, 17-stage, 18-stage microfluidic channel, 181-stage inlet cold pipe, 182-stage outlet cold pipe, 19-slide, 20-refrigeration device, 21-refrigeration balancer, 22-camera assembly, 211-outer frame, 212-cooling plate, 213-limiting buckle, 214-cold storage container, 215-observation window, 216-cooling top plate, 217-phase change material. DETAILED DESCRIPTION

[0041] The present invention will be further described in detail below in conjunction with the embodiments and drawings.

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention.

[0043] Example:

[0044] A micro-nano impact indentation test device based on cyclic refrigeration in the present invention mainly comprises a linear motor 1, a driving platform 2, a piezoelectric stack 4, a pressure rod 8, an infrared thermal imaging component 11, a stage 17, a slide 19, and a refrigeration device 20, wherein the driving platform 2 is arranged on the linear motor 1, and can move toward the stage 17 under the drive of the linear motor 1, and under the action of the linear motor 1, drive the linear motor 1 to move toward the stage 17. Figure 2 The components on the driving platform 2 shown as a whole move along the displacement output direction of the linear motor 1.

[0045] exist Figure 2 It can also be seen that a hinge base 3 is also provided on the driving platform 2, and a connected piezoelectric stack 4 and a pressure rod 8 are provided on the hinge base 3. A diamond indenter 10 is provided at the tip of the pressure rod 8, so that the pressure rod 8 and the diamond indenter 10 can move toward the stage 17 under the push of the piezoelectric stack 4, and a force sensor 5 is provided between the pressure rod 8 and the piezoelectric stack 4 for obtaining the driving force applied by the piezoelectric stack 4 to the pressure rod 8. The structure of this part can refer to the relevant description of the electromagnetic-piezoelectric coupling impact module in Chinese patent CN118111838A. The main working process is that when the driving platform 2 drives the hinge base 3 to move to the test position as a whole, the piezoelectric stack 4 can further provide "electromagnetic-piezoelectric" coupling impact to the pressure rod 8, so that the diamond indenter 10 at its tip generates an indentation on the surface of the sample 14 to be tested, thereby realizing the impact pressing performance test.

[0046] See also Figure 3 , the stage 17 is arranged on the slide 19, and a clamp 15 is arranged on the surface facing the pressure rod 8. The clamp 15 can stably clamp the sample 14 to be tested, and the diamond indenter 10 can move to contact with the sample 14 to be tested. The stage 17 can move along the slide 19 to a position where the sample 14 to be tested is directly opposite to the tip of the pressure rod 8. In this embodiment, the slide 19 is a sliding member with a single degree of freedom, that is, the stage 17 moves up and down along the slide 19, thereby adjusting the contact position between the sample 14 to be tested and the diamond indenter 10. The clamp 15 can refer to the conventional plane clamping structure in the prior art. When an experiment is required, the sample 14 plate to be tested is set on the clamp 15, and the diamond indenter 10 is moved to a position sufficiently close to the sample 14 to be tested.

[0047] In this embodiment, a protective gas channel 16 capable of spraying protective gas toward the hinge base 3 is further provided on the slide 19. Since the impact pressure test environment tracked by the present invention is a low-temperature test, it is easy to cause condensation of moisture in the environment and interfere with the test process. Therefore, the protective gas channel 16 is provided to spray protective gas toward the test position, and a low-water atmosphere is formed in the experimental area by discharging gas with a high water content in the experimental area. The use of the protective gas channel 16 can also refer to the description of the nitrogen generation module in Chinese patent CN118111838A, that is, directly connect it to the protective gas source, based on The protective gas can be supplied and stopped at any time as needed. Therefore, nitrogen can also be used as the protective gas in the present invention. In addition, the application environment of the experimental device in the present invention can be divided into a closed type and an open type. The use of the closed type can also refer to the above-mentioned Chinese patent. The gas injection method is to inject the protective gas into the closed box where the device is located and discharge all high-water-containing gases to avoid interference from moisture condensation. When the device in the present invention is open for experiment, it is necessary to adjust the flow rate generated by the protective gas channel 16 to generate an air curtain in the part between the pressure rod 8 and the stage 17, and the position where the force sensor 5 is located.

[0048] See also Figure 1 The infrared thermal imaging component 11 is arranged on one side of the pressure rod 8, and its infrared thermal imaging range includes the force sensor 5, the pressure rod 8, the sample to be tested 14 and the stage 17. The function of the infrared thermal imaging component 11 is to uniformly monitor the temperature changes during the experiment. It can adopt the more common infrared monitoring equipment in this field, such as an infrared camera. Its monitoring range should include components such as the force sensor 5, the pressure rod 8, the sample to be tested 14 and the stage 17 that may be affected by temperature and produce performance changes. The collected data can be connected to an external host or electronic control module. The connection method can refer to the setting method of the host and the electronic control module in Chinese patent CN118111838A. In addition, all devices or electronic components in this device that need to implement electronic control or data collection can also be connected to an external host or electronic control module through electrical connection. This type of electronic control method is not limited to the control of the infrared thermal imaging component 11.

[0049] See also Figure 1 The refrigeration device 20 is arranged on one side of the pressure rod 8, and is connected to the pressure rod microchannel 7 buried inside the pressure rod 8 through the pressure rod inlet cold pipe 71 and the pressure rod outlet cold pipe 72 to form a circulation pipeline, so that the refrigeration device 20 can circulate the refrigerant inside the pressure rod 8; the refrigeration device 20 is also connected to the stage microchannel 18 buried inside the stage 17 through the stage inlet cold pipe 181 and the stage outlet cold pipe 182 to form a circulation pipeline, so that the refrigeration device 20 can circulate the refrigerant inside the stage 17. Figure 6 , Figure 7It can be seen that the pressure rod 8 is provided with a pressure rod microchannel 7. The arrangement of the pressure rod microchannel 7 can refer to the spirally arranged medium heat conduction pipe in the prior art, which is respectively connected to the pressure rod inlet cold pipe 71 and the pressure rod outlet cold pipe 72 to form a heat conduction circulation structure, thereby the heat conduction medium can be circulated into the pressure rod microchannel 7 through the refrigeration device 20, combined with Figure 2 It can be further seen that the pressure rod inlet cold pipe 71 is connected to the pressure rod microchannel 7 on the side closer to the diamond indenter 10, that is, the circulation mode of the heat-conducting medium should be that the pressure rod inlet cold pipe 71 enters the pressure rod microchannel 7, and then the heat-conducting medium after heat exchange is discharged by the pressure rod outlet cold pipe 72, so as to give priority to ensuring the stability of the temperature of the diamond indenter 10. At the same time, the present invention needs to implement the test under low temperature conditions, so the heat-conducting medium should be a cooling medium, and the circulation of the cooling medium should run through the entire test process, so as to achieve the pressure rod 8 being kept under low temperature conditions during the entire process; similarly, by Figure 8 , Fig. 9 It can be seen that the stage 17 also uses a low-temperature medium circulation cooling method similar to the pressure rod 8 to cool down. Figure 3 It can be further seen that the stage inlet cold pipe 181 should be connected to the stage microchannel 18 on the side closer to the sample 14 to be tested, thereby giving priority to ensuring the stability of the temperature of the sample 14 to be tested. Since the diameters of the pressure rod microchannel 7 and the circulating cold pipe may be different from those of the stage microchannel 18 and the circulating cold pipe, in order to eliminate the influence of different pipe diameters on the refrigeration effect, two sets of independent refrigeration hosts can be integrated in the refrigeration device 20 to cool the pressure rod 8 and the stage 17 separately, thereby achieving precise control of the temperature of the diamond indenter 10 and the sample 14 to be tested.

[0050] The refrigeration device 20 can refer to the heat exchange equipment such as the ice machine conventionally used in the prior art. Obviously, its heat dissipation end should be arranged away from the pressure rod 8 and the stage 17. In particular, when the experimental device in the present invention is built into a sealed box for experiment, the refrigeration device 20 or the heat dissipation end of the refrigeration device 20 should be arranged outside the sealed box to avoid the generated heat affecting the low-temperature environment required by the entire experimental device.

[0051] See also Figure 1A cooling wire 12 is also provided between the pressure rod 8 and the stage 17, wherein one end of the cooling wire 12 is connected to a position close to the diamond indenter 10, and the other end thereof is connected to a position close to the sample 14 on the stage 17, so that heat exchange can be performed between the pressure rod 8 and the stage 17 through the cooling wire 12. As can be seen from the above, due to the difference in specifications and dimensions between the pressure rod 8 and the stage 17, the specifications of the micro-channels therein are also different. At the same time, it is difficult to achieve completely consistent cooling power between different refrigeration devices 20. As a result, the temperature between the pressure rod 8 and the stage 17 during the experiment is usually not completely equal to the set experimental temperature, resulting in a temperature difference between the diamond indenter 10 and the sample 14 to be tested, which is equivalent to introducing an additional temperature variable during the experiment, further affecting the accuracy of the impact pressing test results. Therefore, the present invention sets a cooling wire 12 between the pressure rod 8 and the stage 17. The cooling wire 12 can be composed of a plurality of groups of thin wires of materials with good thermal conductivity, which forms contact between the pressure rod 8 and the stage 17, thereby allowing the heat of the two to be transferred to each other between the cooling wire 12, which is convenient for balancing the temperature difference between the two and eliminates the temperature error caused by the different cooling amounts generated by different refrigeration devices 20 to a certain extent. In this embodiment, the material of the cooling wire 12 is copper, which has good ductility and excellent thermal conductivity. In addition, if the cooling wire 12 is too long, the efficiency of heat conduction will be reduced, and if it is too short, the result of the impact pressing process may be affected due to the stretching effect. Therefore, the cooling wire 12 should be selected according to the experimental needs. The appropriate length.

[0052] See also Figure 1 , Figure 4 , Figure 5 A refrigeration balancer 21 is also provided below the pressure rod 8, wherein the refrigeration balancer 21 includes an outer frame 211, a cold conduction plate 212, a limit hook 213, and a cold storage container 214. The outer frame 211 is a hollow container with at least one set of side openings, at least a portion of its top surface is a cold conduction plate 212, and a limit hook 213 is provided above the top surface, which is close to the cold conduction plate 212. The limit hook 213 can clamp the cold conduction line 12 on the top surface of the outer frame 211 and keep it in contact with the cold conduction plate 212. It can be seen that during the experiment, the limit hook 213 on the top of the refrigeration balancer 21 can clamp the cold conduction line 12 to keep it in contact with the cold conduction plate 212, thereby avoiding the inability to conduct temperature due to the loss of contact between the cold conduction line 12 and the cold conduction plate 212 during the impact pressing experiment.

[0053] The outer frame 211 is provided with a removable cold storage container 214 that completely fills its internal space. The cold storage container 214 can be removed and replaced as needed. The cold storage container 214 has at least one transparent observation window 215 on the side, and the observation window 215 is located at the side opening of the outer frame 211. The top of the cold storage container 214 is a cold conduction top plate 216. The cold storage container 214 is filled with a phase change material 217, so that the phase change material 217 can sequentially pass through the cold conduction top plate 216 and the cold conduction plate 212 to perform heat exchange with the cold conduction line 12. The phase change material 217 17 can fully release or absorb latent heat during the phase change process, so that the temperature of the environment can remain stable for a long time. The cold storage container 214 is arranged behind the outer frame 211, and the phase change material 217 can provide cold energy to the pressure rod 8 and the stage 17 respectively through the cooling wire 12 (that is, absorb the heat of both), so that the temperature of the pressure rod 8 and the stage 17 is stabilized at the phase change point temperature, that is, the temperature required for the experiment, ensuring that the pressure rod 8 and the stage 17 can be maintained at the experimental temperature during the impact pressing process, thereby ensuring the accuracy of the experimental results. Obviously, in order to ensure that the phase change material can achieve the effect of absorbing heat and providing cooling, it is necessary to make the low-temperature phase change point of the phase change material equal to the experimental temperature. Therefore, before the experiment, it is necessary to fill the cold storage container 214 with the phase change material 217 according to the temperature conditions of the experiment, and pre-cool it to a phase change point temperature equal to the experimental temperature. The phase change material 217 is preferably a material with a wide phase change point range such as a phase change polymer. In addition, since the heat transfer process between the phase change material 217 and the cooling line 12 needs to pass through the cooling top plate 216 and the cooling plate 212 in turn, the component materials of the cooling top plate 216 and the cooling plate 212 are preferably made of materials with higher thermal conductivity than the cooling line 12. In this embodiment, the same copper material is used.

[0054] In this embodiment, a camera assembly 22 is provided on one side of the refrigeration balancer 21. The camera area of ​​the camera assembly 22 includes the entire observation window 215. The camera assembly 22 can use the conventional camera equipment used in the prior art. Its use method is the same as that of the infrared thermal imaging assembly 11, that is, it is electrically connected to an external host or an electronic control module, and the collected video data is directly transmitted to the external host or the electronic control module. The function of the camera assembly 22 is to observe the state of the phase change material 217 through the observation window 215. When the camera assembly 22 observes the phase change material When 217 is in a state of two-phase coexistence, it means that the phase change material 217 is at the phase change point, the temperature will be stable and unchanged, and it can stably absorb heat and provide cooling for the pressure rod 8 and the stage 17, as well as the diamond indenter 10 and the sample 14 respectively arranged thereon. The experimental data collected at this time is accurate data. If the camera component 22 observes that the phase change material 217 is in a single phase other than the phase change point, it means that the phase change material 217 can no longer stably absorb heat and provide cooling. At this time, the data collected in the experiment is suspicious data, and it is necessary to judge whether to retain it according to the specific situation. In addition, when the experimental device is set in a closed box, the camera component 22 can assist in observing the internal situation.

[0055] See also Figure 3 and Figure 6 A pressure rod thermocouple 9 is provided on the pressure rod 8 near the diamond indenter 10, and a stage thermocouple 13 is provided on the stage 17 near the sample 14 to be tested, and the distance between the pressure rod thermocouple 9 and the diamond indenter 10 and the distance between the stage thermocouple 13 and the sample 14 to be tested are both within 0.5 mm. In addition to using the infrared thermal imaging component 11 to obtain temperature information, the thermocouples directly provided on the pressure rod 8 and the stage 17 can obtain the temperature change information of the two during the experiment in a more real-time and accurate manner, and the contact distances between the two thermocouples and the diamond indenter 10 and the sample 14 to be tested are both within 0.5 mm, so that the temperature data of the diamond indenter 10 and the sample 14 to be tested can be obtained without affecting the impact pressing experiment.

[0056] In this embodiment, a cold-isolating baffle 6 is provided between the force sensor 5 and the pressure rod 8 to prevent the low temperature from being transmitted to the force sensor 5. The cold-isolating baffle 6 is mainly used to contain and block the cold. Its material can be an aluminum silicate ceramic material that is inexpensive, easy to process, and has a good cold-isolating effect. It can minimize the conduction of low temperature to the force sensor 5 and affect the measurement accuracy of the force sensor 5.

[0057] In addition, the surfaces of the pressure rod inlet cold pipe 71, the pressure rod outlet cold pipe 72, the loading platform inlet cold pipe 181, and the loading platform outlet cold pipe 182 in this embodiment are all covered with thermal insulation material, which can reduce low-temperature dissipation and further improve the cooling efficiency of the pressure rod 8 and the loading platform 17.

[0058] The test method of the above-mentioned micro-nano impact indentation test device based on cyclic refrigeration is:

[0059] Step S1: assembling the refrigeration pipeline according to the device, fixing the sample to be tested on the stage, installing the diamond indenter on the pressure rod, and adjusting the stage and the pressure rod so that the position of the diamond indenter corresponds to the position of the sample to be tested;

[0060] Step S2: The cooling wire is clamped in the limit hook of the refrigeration balancer to keep it in contact with the cooling plate, and a phase change material having a phase change point equal to the experimental temperature is filled in the cold storage container according to the experimental requirements, and the phase change material is pre-cooled to the phase change point temperature;

[0061] Step S3: outputting protective gas through the protective gas channel, setting the infrared thermal imaging component and the camera component to a working state, starting the refrigeration device to circulate and cool the pressure head and the stage respectively until the experimental temperature is reached, and setting a cold storage container filled with a phase change material that has been pre-stored cold in a refrigeration balancer, and supplying cold to the pressure head and the stage respectively from the phase change point in the cold storage container, so that the temperature of both can be stably maintained at the phase change point temperature, i.e., the experimental temperature;

[0062] Step S4: After observing that the indenter and the stage are stable at the experimental temperature, control the drive platform and piezoelectric stack and other components to perform a low-temperature impact indentation experiment, and collect mechanical, displacement and temperature data related to the impact indentation experiment, wherein the displacement data is the displacement data of the diamond indenter in the low-temperature impact indentation experiment. The data can be collected by referring to the conventional method of obtaining displacement data in the prior art, and a displacement sensor with a data acquisition range that can cover the entire moving range of the diamond indenter is set on the device or on the side.

[0063] In summary, the present invention adopts two-stage drive to realize "electromagnetic-piezoelectric" coupled impact, and the piezoelectric stack completes the "transient pressing" after the linear motor realizes "long-range approach", and obtains the mechanical test data of the material through the force sensor, obtains the displacement data of the diamond indenter through the displacement sensor, obtains the temperature data of the diamond indenter and the sample to be tested through the thermocouple, and utilizes the driving platform and the slide table to realize the function of applying load at any point of the sample, thereby completing the dot matrix low-temperature impact pressing performance test of the sample.

[0064] Among them, the low-temperature loading method uses an embedded microchannel to cool the sample and the pressure head to be tested at the same time, and uses a cooling wire to quickly balance the temperature difference. At the same time, a detachable cold storage container with a built-in phase change material in contact with the cooling wire is used to supply cooling for the sample and the pressure head. The phase change heat absorption process of the phase change material keeps the temperature of the sample and the pressure head stable at the preset temperature of the experiment, so that the temperature conditions of the experiment are precisely controlled, eliminating the temperature difference between the sample and the pressure head, and effectively solving the problem of temperature drift affecting the test accuracy.

[0065] In addition, the experimental device can adjust the output power in real time according to the information feedback from the thermocouple and the infrared thermal imaging component. The temperature can be continuously adjusted by adjusting the temperature of the refrigerant medium and replacing the cold storage container. It has a simple structure and compact layout. It does not require an atmosphere refrigeration chamber and is easy to integrate into the tester multi-physics field in-situ monitoring components. It provides a highly accurate method for revealing the microscopic failure mechanism of materials under low-temperature impact conditions and the evolution of their performance.

[0066] In the description of the present invention, it should be pointed out that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and should not be understood as a limitation on the present invention.

[0067] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the embodiments of the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A micro-nano impact indentation test device based on cyclic refrigeration, characterized in that: It comprises a linear motor (1), a driving platform (2), a piezoelectric stack (4), a pressure rod (8), an infrared thermal imaging component (11), a stage (17), a slide (19), and a refrigeration device (20), wherein: The driving platform (2) is arranged on the linear motor (1) and can move toward the object platform (17) under the drive of the linear motor (1); a hinge base (3) is also arranged on the driving platform (2); a connected piezoelectric stack (4) and a pressure rod (8) are arranged on the hinge base (3); a diamond pressure head (10) is arranged at the tip of the pressure rod (8), so that the pressure rod (8) and the diamond pressure head (10) can move toward the object platform (17) under the push of the piezoelectric stack (4); a force sensor (5) is arranged between the pressure rod (8) and the piezoelectric stack (4) for obtaining the driving force applied by the piezoelectric stack (4) to the pressure rod (8); The stage (17) is arranged on a slide (19), and a clamp (15) is arranged on the surface of the stage (17) facing the pressure rod (8), the clamp (15) can stably clamp the sample (14) to be tested, and the diamond indenter (10) can move to contact the sample (14) to be tested, and the stage (17) can move along the slide (19) to a position where the sample (14) to be tested is directly opposite to the tip of the pressure rod (8); The infrared thermal imaging component (11) is arranged on one side of the pressure rod (8), and its infrared thermal imaging range includes the force sensor (5), the pressure rod (8), the sample to be tested (14) and the loading platform (17); The refrigeration device (20) is arranged on one side of the pressure rod (8), and is connected to the pressure rod microchannel (7) buried inside the pressure rod (8) through the pressure rod inlet cold pipe (71) and the pressure rod outlet cold pipe (72) to form a circulation pipeline, so that the refrigeration device (20) can circulate the refrigeration medium inside the pressure rod (8); the refrigeration device (20) is also connected to the loading platform microchannel (18) buried inside the loading platform (17) through the loading platform inlet cold pipe (181) and the loading platform outlet cold pipe (182) to form a circulation pipeline, so that the refrigeration device (20) can circulate the refrigeration medium inside the loading platform (17); A cooling wire (12) is also provided between the pressure rod (8) and the stage (17), wherein one end of the cooling wire (12) is connected to a position close to the diamond indenter (10), and the other end is connected to a position on the stage (17) close to the sample to be tested (14), so that heat exchange can be performed between the pressure rod (8) and the stage (17) through the cooling wire (12).

2. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 1, characterized in that: A refrigeration balancer (21) is arranged below the pressure rod (8), wherein the refrigeration balancer (21) comprises an outer frame (211), a cold conduction plate (212), a limit hook (213), and a cold storage container (214); the outer frame (211) is a hollow container with at least one set of side openings, at least a portion of its top surface is a cold conduction plate (212), and a limit hook (213) is arranged above the top surface and is arranged close to the cold conduction plate (212); the limit hook (213) can clamp the cold conduction line (12) on the top surface of the outer frame (211) to keep it in contact with the cold conduction plate (212); A cold storage container (214) completely filling the internal space of the outer frame (211) is detachably provided inside the outer frame (211); the cold storage container (214) has at least one transparent observation window (215) on the side, and the observation window (215) is located at the side opening of the outer frame (211); the top of the cold storage container (214) is a cold conduction top plate (216); the cold storage container (214) is filled with a phase change material (217), so that the phase change material (217) can sequentially pass through the cold conduction top plate (216) and the cold conduction plate (212) to perform heat exchange with the cold conduction line (12).

3. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 2, characterized in that: A camera assembly (22) is provided on one side of the refrigeration balancer (21), and the camera area of ​​the camera assembly (22) includes the entire observation window (215).

4. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 2, characterized in that: The material of the cooling wire (12), the cooling plate (212) and the cooling top plate (216) is red copper.

5. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 1, characterized in that: A pressure rod thermocouple (9) is arranged on the pressure rod (8) near the diamond indenter (10), and a stage thermocouple (13) is arranged on the stage (17) near the sample to be tested (14), and the distance between the pressure rod thermocouple (9) and the diamond indenter (10) and the distance between the stage thermocouple (13) and the sample to be tested (14) are both within 0.5 mm.

6. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 1, characterized in that: A cold-insulating baffle (6) is provided between the force sensor (5) and the pressure rod (8) to prevent low temperature from being conducted to the force sensor (5).

7. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 1, characterized in that: The surfaces of the pressure rod inlet cold pipe (71), the pressure rod outlet cold pipe (72), the loading platform inlet cold pipe (181), and the loading platform outlet cold pipe (182) are all coated with heat-insulating materials.

8. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 1, characterized in that: The slide table (19) is also provided with a protective gas channel (16) capable of spraying protective gas toward the hinge base (3).

9. The micro-nano impact indentation testing device based on cyclic refrigeration according to claim 1, characterized in that: The slide table (19) is a sliding member with a single degree of freedom in upper and lower directions.

10. A micro-nano impact indentation test method based on cyclic refrigeration, characterized in that: The test is performed using the device as described in any one of claims 1 to 9, comprising the following steps: Step S1: assembling the refrigeration pipeline according to the device, fixing the sample to be tested on the stage, installing the diamond indenter on the pressure rod, and adjusting the stage and the pressure rod so that the position of the diamond indenter corresponds to the position of the sample to be tested; Step S2: The cooling wire is clamped in the limit hook of the refrigeration balancer to keep it in contact with the cooling plate, and the phase change material corresponding to the experimental temperature is filled in the cold storage container according to the experimental requirements, and the phase change material is pre-cooled at the experimental temperature; Step S3: outputting the protective gas through the protective gas channel, setting the infrared thermal imaging component and the camera component to a working state, starting the refrigeration device to cyclically cool the pressure head and the stage respectively until the experimental temperature is reached, and placing the cold storage container filled with the pre-cold phase change material in the refrigeration balancer; Step S4: After observing that the indenter and the stage are stable at the experimental temperature, control the drive platform and piezoelectric stack and other components to perform a low-temperature impact indentation experiment, and collect relevant data of the impact indentation experiment.

Images