Surface mechanical property test platform for realizing bidirectional temperature gradient and test method thereof

Abstract

According to the surface mechanical property test platform for realizing the bidirectional temperature gradient and the test method thereof provided by the invention, a certain temperature difference can be formed in different directions through the heating sheet and the water cooling box, so that a surface with a certain temperature gradient is formed; and a mechanical testing system composed of a laser range finder and an elastic cantilever beam is used for measuring the adhesion force and the friction force. The adhesion behavior evolution mechanism and friction rule change characteristics of the micro-nano structure surface under the influence of the temperature gradient can be disclosed, so that test support is provided for key scientific problems such as multifunctional surface design and interface regulation and control, and development of a new generation of multifunctional surface mechanical test instruments is promoted.

Description

Technical Field

[0001] This invention relates to the field of mechanical property testing, specifically to a surface mechanical property testing platform and method that realizes a two-way temperature gradient. Background Technology

[0002] With the rapid development of functional materials, biomimetic surface engineering, micro / nano manufacturing, and precision mechanics, higher demands are being placed on the adhesion and friction properties of material surfaces at the micro / nano scale. Surface adhesion and friction behavior directly affect the durability, responsiveness, and energy efficiency of devices in practical applications. Especially in the field of multifunctional surface design and interface control, surface mechanical behavior exhibits significant differences under different environmental conditions. Particularly in wet or liquid media, the adhesion and friction mechanisms are more complex, and accurate characterization of microscopic interface behavior has become a key technical bottleneck restricting performance optimization. At the micro / nano scale, the interfacial behavior of materials is not only affected by mechanical loads and the medium environment, but also by temperature gradient changes, which significantly impact adhesion, friction, and interfacial stability. Particularly in research involving thermosensitive materials, temperature-driven adhesion systems, and biological surface regulation mechanisms, numerous studies have shown that micro / nano structures exhibit significant thermal expansion / contraction behavior, surface free energy changes, and molecular rearrangement effects under temperature changes, thus affecting surface adhesion and friction behavior. The interfacial energy changes and interaction regulation caused by temperature gradients have become a cutting-edge research direction at the intersection of surface science and materials physics.

[0003] In the process of deeply understanding and controlling various surface mechanical behaviors (such as adhesion, friction, etc.), it is of great significance to build a convenient, highly versatile and high-precision surface mechanical testing platform for materials science, interface physics and bioengineering. Over the past few decades, researchers have developed a variety of micro-force measurement devices to achieve quantitative characterization of the mechanical response of different material systems surfaces—especially at the micro- and nano-scale. Among them, the SurfaceForces Apparatus (SFA) is a classic mechanical characterization platform. Its design is based on a highly sensitive cantilever beam structure and combined with the Fringe of Equal Chromatic Order (FECO) imaging technology, which can achieve high-resolution measurement of the interaction forces between nano-thick liquid films and solid interfaces [5]. SFA can accurately resolve various interfacial interactions such as intermolecular van der Waals forces, electrostatic forces and capillary forces at the sub-nanometer to micrometer scales, and is widely used in micro- and nano-tribology, soft matter rheology, lubricant performance evaluation and material interface adhesion characteristics research.

[0004] Although there are many surface mechanics testing devices, most traditional devices have the following limitations: (1) The testing environment is singular, making it difficult to fully characterize the surface mechanical behavior in different directions (such as horizontal and vertical directions), thus limiting the testing dimensions; (2) The functional integration is low, usually only having the ability to test one of friction or adhesion, and unable to achieve the coordinated testing of friction and adhesion on a unified platform; (3) The environmental simulation capability is insufficient, especially the impact of temperature gradient changes, which limits the research on thermally driven interface behavior; (4) The equipment is expensive and the maintenance cost is high, which limits its widespread application in universities and small and medium-sized research units.

[0005] To address the aforementioned technical challenges, current research trends are moving towards multifunctional integration, strong environmental adaptability, high measurement accuracy, and economical and reliable operation. Particularly in complex environments with multi-directional measurements and stable temperature gradients, achieving efficient and stable measurements of the adhesion and friction properties of micro / nanostructure interfaces has become a key requirement for the research and development of surface and interface mechanics and related application technologies. Summary of the Invention

[0006] To address the problems of existing technologies, this invention provides a surface mechanical property testing platform and method that achieves bidirectional temperature gradients. This platform can generate stable temperature gradients in both horizontal and vertical directions, enabling the measurement of friction and adhesion forces under both dry and lubricated conditions. It offers advantages such as multi-directional measurement and the ability to generate stable temperature gradients. This invention provides a surface mechanical property testing platform for achieving a two-way temperature gradient, comprising a vibration isolation table, a displacement device, a cantilever beam force measurement system, a laser rangefinder, and a testing platform. The displacement device includes a displacement platform with x-axis and y-axis degrees of freedom. The testing platform is fixed at the top of the displacement platform and includes a ceramic heat insulation plate with a heating module and a cooling module at each end. The cantilever beam force measurement system is fixed above the vibration isolation table by a frame and includes a cantilever beam, a reflecting mirror, and a sample clamp. The cantilever beam is fixed to the frame and includes a normal double-layer parallel beam and a tangential double-layer parallel beam. The reflecting mirror is fixed on the cantilever beam and includes a vertical reflecting mirror and a horizontal reflecting mirror. The sample clamp is fixed at the end of the cantilever beam and is parallel to the testing platform. The laser rangefinder includes a vertical laser rangefinder, a horizontal laser rangefinder, and a laser receiver. The vertical and horizontal laser rangefinders are aligned with the vertical and horizontal reflecting mirrors, respectively, and the laser receiver receives the reflected light from the reflecting mirrors.

[0007] In a further improvement, the cantilever beam in the cantilever beam force measurement system is fixedly connected to the frame via a spring leveling device.

[0008] In a further improvement, the load displacement platform is connected to a vertical displacement motor and a horizontal displacement motor.

[0009] In a further improvement, the heating module includes a power supply, a temperature controller, a relay, a thermocouple, and a heating element, wherein the heating element is fixedly connected to a ceramic heat insulation plate, and the temperature controller adjusts the heat of the heating element through the relay and the thermocouple.

[0010] In a further improvement, the refrigeration module includes a water-circulating refrigeration box, insulated pipes, and a water-cooling head. The water-cooling head is fixedly connected to a ceramic heat insulation plate, and the water-circulating refrigeration box is connected to the water-cooling head through insulated pipes.

[0011] Further improvements include the testing platform comprising a horizontal testing platform or a vertical testing platform. The present invention also provides a surface mechanical property testing method for realizing a two-way temperature gradient, which uses the surface mechanical property testing platform for realizing a two-way temperature gradient, including: adhesion force testing and friction force testing.

[0012] During the adhesion force test, the load displacement platform is adjusted to move at a set speed, so that the sample on the test platform gradually contacts or separates from the sample on the sample holder, thereby causing the cantilever beam structure to generate a displacement response. During the displacement process, the deformation displacement of the cantilever beam is detected in real time by a laser rangefinder device, and the mechanical parameters of the beam are converted to accurately calculate the magnitude and variation law of the adhesion force during the loading process, so as to realize the full recording of dynamic adhesion behavior. During the friction test, the load displacement platform is adjusted to move a certain distance or reciprocate at a set speed in the horizontal direction, so that friction is generated between the sample on the test platform and the sample on the sample holder, simulating the actual friction situation; during the friction movement, the cantilever beam is offset, and its displacement is measured by a laser rangefinder and combined with the beam parameters to deduce the process of friction change at the contact interface.

[0013] In a further improvement, during the adhesion force test and friction force test, heating and cooling are performed by heating and cooling modules respectively, forming a stable linear temperature gradient field on the sample interface of the test platform.

[0014] In a further improvement, during the heating process, a temperature controller is used to set the hot end temperature, and feedback adjustment is performed through relays and thermocouples to stabilize the temperature within a certain value of ±3℃; during the cooling process, a water-circulating cooling box delivers the constant temperature to the water cooling head through insulated pipes, while simultaneously removing the generated heat, thereby maintaining a constant cold end temperature.

[0015] In a further improvement, the laser rangefinder measurement process specifically involves emitting a laser beam, which is then reflected back to the laser receiver via a reflective lens, thereby accurately measuring the offset distance and calculating the magnitude of the force applied.

[0016] The beneficial effects of this invention are as follows: 1. It can achieve a stable and controllable temperature gradient in both horizontal and vertical directions, and has the ability to measure adhesion and friction.

[0017] 2. Ceramic heat insulation plates have good thermal insulation properties, which helps to establish a significant temperature difference at both ends of the sample interface.

[0018] 3. The heating module consists of heating elements, a temperature controller, thermocouples, and relays. Through closed-loop temperature feedback control, it achieves precise temperature regulation of the heating area, with the control error stably maintained within ±3℃. The cooling module comprises a water-cooled head and a circulating cooling water tank. A circulating cooling water system continuously dissipates heat from the cold end, thereby maintaining a constant cold end temperature. This experimental setup can create a stable linear temperature gradient field at the sample interface, enabling precise control of the interface's thermal response behavior.

[0019] 4. In terms of mechanical testing, the double-layer parallel beam design method can not only meet the measurement of horizontal friction force and vertical adhesion force, but also effectively suppress the free end tilting error generated by the cantilever beam during deformation by taking advantage of the geometric characteristics of the parallelogram mechanism, ensuring that the force measuring point maintains the translational trajectory, thereby significantly improving the measurement accuracy and repeatability.

[0020] 5. The structure is simple in design, highly modular, and has good ease of installation and disassembly and structural reliability. It is suitable for quick replacement and debugging under different testing requirements, which improves the versatility of the platform and experimental efficiency. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the horizontal testing platform structure used in this invention.

[0023] Figure 2 This is a schematic diagram of the vertical testing platform structure used in this invention.

[0024] Figure 3 This is a schematic diagram of the heating system.

[0025] Figure 4 This is a diagram of the heating system.

[0026] Figure 5 This is a schematic diagram of a refrigeration system.

[0027] Figure 6 This is a diagram of a refrigeration system.

[0028] Figure 7 This is a schematic diagram of a double-layer parallel cantilever beam structure.

[0029] In the diagram, 1-Test platform; 2-Horizontal laser rangefinder; 3-Displacement platform; 4-Horizontal displacement motor; 5-Vibration isolation table; 6-Vertical displacement motor; 7-Frame; 8-Vertical laser rangefinder; 9-Heating element; 10-High temperature resistant ceramic heat insulation board; 11-Water cooling head; 12-Spring leveling device; 13-Cantilever beam force measurement system; 14-24V output power supply; 15-Temperature controller; 16-Thermocouple; 17-Relay; 18-Water circulation cooling box; 19-Insulated pipe; 20-Water cooling head; 21-Normal double-layer parallel beam; 22-Tangential double-layer parallel beam; 23-Mounting bracket; 24-Sample clamp; 25-Horizontal reflecting mirror; 26-Vertical reflecting mirror. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] A specific embodiment of the present invention has the following structure: Figure 1 and Figure 2As shown, the system includes a vibration isolation table 5, a displacement device, a cantilever beam force measurement system 13, a laser rangefinder, and a test platform 1. The test platform includes a horizontal test platform and a vertical test platform. The displacement device includes a load displacement platform 3 with x-axis and y-axis degrees of freedom. The test platform is fixed at the upper end of the load displacement platform and includes a ceramic heat insulation plate 10. Heating and cooling modules are respectively provided at both ends of the ceramic heat insulation plate 10. The cantilever beam force measurement system is fixed above the vibration isolation table 5 by a frame 7 and includes a cantilever beam, a reflecting mirror, and a sample clamp 24. The cantilever beam is fixed to the frame 7 by a spring leveling device 12, and includes a normal double-layer parallel beam 21 and a tangential double-layer parallel beam 22; the reflector is fixed on the cantilever beam and includes a vertical reflector 26 and a horizontal reflector 25; the sample clamp 24 is fixed at the end of the cantilever beam and is parallel to the test platform; the laser rangefinder includes a vertical laser rangefinder 8, a horizontal laser rangefinder 2 and a laser receiver, the vertical laser rangefinder and the horizontal laser rangefinder are respectively aligned with the vertical reflector 26 and the horizontal reflector 25, and the laser receiver receives the reflected light from the reflector.

[0032] One specific embodiment of the present invention is as follows: 1. Temperature gradient control and regulation system design: Temperature gradients are generated in different directions. By adjusting the installation method of the clamps, the temperature gradient in the horizontal direction can be achieved. Figure 1 ) and vertical direction ( Figure 2 Flexible switching between ( ).

[0033] (1) Heating module design: such as Figure 3 As shown, the heating module consists of a 24V power supply 14, a temperature controller 15, a relay 17, a thermocouple 16, and a heating element 9. The heating element 9 is placed in a high-temperature resistant ceramic heat insulation plate 10. During heating, the temperature of the hot end is set by the temperature controller, and feedback adjustment is performed through the relay and thermocouple, so that the temperature can be stabilized within a certain value within ±3℃.

[0034] (2) Cooling module design: such as Figure 4 As shown, the refrigeration module consists of a water-circulating refrigeration box 18, insulated pipes 19, and a water-cooled head 20. During refrigeration, the water-cooled head 20 is fixed on the high-temperature resistant ceramic heat insulation plate 10, and the water-circulating refrigeration box delivers heat at a constant temperature to the water-cooled head through the insulated pipes, while simultaneously removing the generated heat, thereby maintaining a constant cold end temperature.

[0035] 2. Design of Surface Mechanical Measurement System: The system employs a tangential double-layer parallel beam 22 fixed to the frame 7 with screws, which will exhibit a displacement angle when measuring frictional force. A normal double-layer parallel beam 21 is also fixed to the frame with screws, exhibiting a displacement angle when measuring adhesion force, and can also measure the normal pressure exerted on the sample during friction. As a key structural unit for force transmission and sensitivity control, the material properties of the cantilever beam directly determine the response accuracy, load-bearing capacity, and environmental adaptability of the testing system. Considering factors such as mechanical properties, quality control, thermal stability, and processing characteristics, 7075 aluminum alloy can be selected for the cantilever beam, as this material has advantages such as superior mechanical properties, strong thermal stability, and lightweight. The sample clamp 24 can be designed with different clamps according to the sample shape and measurement direction, and is mounted on the frame with screws. When the cantilever beam is displaced under stress, a laser rangefinder (including a horizontal laser rangefinder 2 and a vertical laser rangefinder 8) emits a laser, which is reflected back to the laser receiver by a reflecting mirror (including a horizontal reflecting mirror 25 and a vertical reflecting mirror 26). This allows for precise measurement of the displacement distance, and thus the magnitude of the force can be calculated.

[0036] When measuring adhesion force, the vertical displacement motor 6 can be used to adjust the load displacement platform 3 for controllable vertical driving. This causes the upper and lower samples to gradually contact or separate, thereby inducing a vertical displacement response in the cantilever beam structure. During the displacement process, the deformation displacement of the cantilever beam is detected in real time by a laser rangefinder device, and converted in conjunction with the mechanical parameters of the beam, the magnitude and variation law of the adhesion force during the loading process can be accurately calculated, realizing the full recording of dynamic adhesion behavior. Similarly, when measuring friction force, the horizontal displacement motor 4 can be used to adjust the load platform to move a certain distance in the horizontal direction at a certain speed, or it can be set to reciprocate to simulate actual friction. During the friction movement, the cantilever beam shifts in the horizontal direction. The displacement is measured by the laser rangefinder, and combined with the beam parameters, the change process of the friction force at the contact interface can be deduced. Furthermore, to comprehensively obtain interface mechanical information, the system can also simultaneously measure the small displacement response of the cantilever beam in the vertical direction during the friction process, and calculate the dynamic change of the normal contact force or normal pressure accordingly. If a temperature gradient is required, heating and cooling modules can be used to heat and cool the sample respectively, thus creating a stable linear temperature gradient field at the sample interface. Different fixtures can be designed to test different surface mechanical properties, such as surface-to-surface, sphere-to-surface, rigid-body-to-elastic body, etc., and surface mechanical properties under dry and wet conditions can also be measured, such as solid-to-solid surfaces, solid-liquid surfaces, etc.

[0037] The modular and adjustable design of this system gives the platform a high degree of versatility and scalability, making it suitable for studying interface behavior under various materials and operating conditions, and meeting multi-dimensional testing needs from basic scientific research to engineering applications.

[0038] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of the present invention. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention, without departing from the principle of the present invention, should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A surface mechanical property testing platform that realizes a two-way temperature gradient, characterized in that: The system includes a vibration isolation table, a displacement device, a cantilever beam force measurement system, a laser rangefinder, and a testing platform. The displacement device comprises a displacement platform with x-axis and y-axis degrees of freedom. The testing platform is fixed to the upper end of the displacement platform and includes a ceramic heat insulation plate with a heating module and a cooling module at each end. The cantilever beam force measurement system is fixed above the vibration isolation table via a frame and includes a cantilever beam, a reflecting mirror, and a sample clamp. The cantilever beam, fixed to the frame, includes a normal double-layer parallel beam and a tangential double-layer parallel beam. The reflecting mirror, including a vertical reflecting mirror and a horizontal reflecting mirror, is fixed to the cantilever beam. The sample clamp is fixed to the end of the cantilever beam and is parallel to the testing platform. The laser rangefinder includes a vertical laser rangefinder, a horizontal laser rangefinder, and a laser receiver. The vertical and horizontal laser rangefinders are aligned with the vertical and horizontal reflecting mirrors, respectively, and the laser receiver receives the reflected light from the reflecting mirrors.

2. The surface mechanical property testing platform for realizing a two-way temperature gradient according to claim 1, characterized in that: In the cantilever beam force measurement system, the cantilever beam is fixedly connected to the frame via a spring leveling device.

3. The surface mechanical property testing platform for realizing a two-way temperature gradient according to claim 1, characterized in that: The load displacement platform is connected to a vertical displacement motor and a horizontal displacement motor.

4. The surface mechanical property testing platform for realizing a two-way temperature gradient according to claim 1, characterized in that: The heating module includes a power supply, a temperature controller, a relay, a thermocouple, and a heating element. The heating element is fixedly connected to a ceramic heat insulation plate, and the temperature controller adjusts the heat of the heating element through the relay and the thermocouple.

5. The surface mechanical property testing platform for realizing a two-way temperature gradient according to claim 1, characterized in that: The refrigeration module includes a water-circulating refrigeration box, insulated pipes, and a water-cooling head. The water-cooling head is fixedly connected to a ceramic heat insulation plate, and the water-circulating refrigeration box is connected to the water-cooling head through insulated pipes.

6. The surface mechanical property testing platform for realizing a two-way temperature gradient according to claim 1, characterized in that: The testing platform includes a horizontal testing platform or a vertical testing platform.

7. A method for testing surface mechanical properties using a bidirectional temperature gradient, comprising the surface mechanical property testing platform for achieving a bidirectional temperature gradient as described in claim 1, characterized in that... include: Adhesion force test and friction force test; During the adhesion force test, the load displacement platform is adjusted to move at a set speed, so that the sample on the test platform gradually contacts or separates from the sample on the sample holder, thereby causing the cantilever beam structure to generate a displacement response. During the displacement process, the deformation displacement of the cantilever beam is detected in real time by a laser rangefinder device, and the mechanical parameters of the beam are converted to accurately calculate the magnitude and variation law of the adhesion force during the loading process, so as to realize the full recording of dynamic adhesion behavior. During the friction test, the load displacement platform is adjusted to move a certain distance or reciprocate at a set speed in the horizontal direction, so that friction is generated between the sample on the test platform and the sample on the sample holder, simulating the actual friction situation; during the friction movement, the cantilever beam is offset, and its displacement is measured by a laser rangefinder and combined with the beam parameters to deduce the process of friction change at the contact interface.

8. The surface mechanical property testing method for realizing a two-way temperature gradient according to claim 7, characterized in that: During the adhesion force test and friction force test, heating and cooling are performed by heating and cooling modules respectively, forming a stable linear temperature gradient field on the sample interface of the test platform.

9. The surface mechanical property testing method for realizing a two-way temperature gradient according to claim 8, characterized in that: During the heating process, the hot end temperature is set using a temperature controller, and feedback adjustment is performed through relays and thermocouples to stabilize the temperature within a certain value of ±3℃. During the cooling process, a water-circulating cooling box delivers the constant temperature to the water cooling head through insulated pipes, while simultaneously removing the generated heat, thereby maintaining a constant cold end temperature.

10. The surface mechanical property testing method for realizing a two-way temperature gradient according to claim 7, characterized in that: The laser rangefinder measurement process specifically involves emitting a laser beam, which is reflected back to the laser receiver by a reflective lens, thereby accurately measuring the offset distance and calculating the magnitude of the force applied.

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