Novel in-situ biaxial creep test device and test method for thin film material

Abstract

The invention provides a novel in-situ biaxial creep test device for a film material. The novel in-situ biaxial creep test device comprises a rack main body, a pulley block, a clamp group, a cross-shaped biaxial sample, a guide rail and a weight, the machine frame body is composed of a base, a machine frame cylinder and a machine frame platform, and four sets of guide rails, clamp sets and pulley sets which are symmetrically distributed are arranged on the machine frame platform. According to the in-situ biaxial creep test device provided by the invention, constant creep acting force is applied to a cross biaxial sample by weights corresponding to four groups of pulley blocks, the gravity of the weights is applied to a clamp group under the supporting action of nylon wires and the pulley blocks, and the clamp group transmits the gravity of the weights to the sample under the sliding action of a guide rail platform; the constant creep acting force is the same as the gravity of the weight. The device is simple in structure, small in size and low in manufacturing cost, multiple sets of creep tests can be conveniently carried out on multiple devices at the same time, and different environment control can be achieved by being matched with different environment boxes.

Description

Technical Field

[0001] The invention belongs to the field of material mechanical property testing, and in particular relates to a novel in-situ biaxial creep test device and test method for thin film materials. Background Art

[0002] With the in-depth development of terminal fields such as food, daily chemicals, medicine, fuel cells and lithium batteries, the market recognition and demand for functional film products are constantly increasing. At the same time, film materials are also widely used in the military industry. For example, as a high-temperature insulation material, radiation protection material and high-temperature substrate material, DuPont commercialized the film in the 1960s, making the film material widely used in aerospace, atomic energy industry, satellites, nuclear submarines, microelectronics and other aspects. However, with the complexity and changeability of the application occasions and application environment of these film products, higher requirements are placed on the durability and structural integrity of film materials.

[0003] Mechanical property testing of thin film materials can further understand the creep resistance and fatigue resistance of materials, provide experimental basis for material life prediction, and evaluate their reliability in actual engineering. Among them, creep failure is the key factor limiting the service life of most thin film materials. Creep testing of thin film materials is of great significance to understanding and improving their material design. Through creep testing, the creep deformation, creep strain rate, creep life, creep crack extension and other indicators of materials under different temperature, humidity, stress and time conditions can be measured to provide reliable creep property data. Creep tests of thin film materials are mostly carried out using existing mechanical testing equipment on the market. These mechanical equipment are often large in size and complex in structure design, and it is difficult to match different environmental chambers for test environment control; due to the relatively long creep test cycle and the high cost of traditional mechanical testing equipment, this will greatly increase the cost of creep testing. Therefore, there is an urgent need for a new and simple creep test device and method dedicated to thin film materials that can be conveniently matched with different test environmental chambers for environmental control. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention proposes a novel in-situ biaxial creep test device and test method for thin film materials. The test device has a simple structure, a small volume, and a low processing cost, and is convenient for cooperating with different test environment boxes to perform creep tests under different environmental conditions; at the same time, the device satisfies the requirements of in-situ biaxial loading of thin film materials, which is more in line with the actual stress conditions of most thin film materials in actual working conditions, and can provide test means and technical support for the study of biaxial creep failure behavior and durability of thin film materials.

[0005] The present invention solves the following technical problems: ① In view of the problems of complex structural design and high cost of the existing creep mechanical testing equipment, a creep testing device with simple structure and low cost specially used for thin film materials is designed; ② In view of the problem of difficult compatibility between traditional mechanical testing machines and different environmental chambers, a miniaturized creep testing device is designed, which is convenient for matching with different environmental chambers to achieve different environmental control; ③ Usually, the creep test cycle is long. The test device of the present invention has low cost, small size and simple structure, so it is convenient to repeatedly set up multiple groups of test devices according to specific test requirements to carry out creep tests simultaneously, which can greatly shorten the test time cycle and monetary cost.

[0006] The novel in-situ biaxial creep test device for thin film materials proposed in the present invention is composed of a frame body, a pulley block, a fixture block, a biaxial specimen of thin film materials, a guide rail, a weight, and a nylon line. The frame body is the main supporting structure of the device, and is composed of a base, a frame cylinder, and a frame platform. The frame cylinder is bolted to the base and the frame platform through countersunk holes and threaded holes respectively; the frame cylinder is set as a cylindrical body with a slender structure, which provides a handle for the movement and placement of the device. The frame platform is set as a cross-shaped table, which provides a platform path for the in-situ biaxial creep loading of the device, and can also save the plate material to the greatest extent and reduce the material cost. Four groups of symmetrically distributed guide rails, fixture blocks, and pulley blocks are arranged on the frame platform. The guide rail adopts a cross roller guide rail, which can minimize the resistance of the guide rail platform when sliding and ensure the lubrication of the guide rail slide; in addition, a slide positioning device is installed on the guide rail, and the guide rail slide can be fixed as needed. The top of the guide rail slide is connected to the clamp group through built-in bolts. The clamp group consists of a clamp base and a clamp top cover, which is used to clamp the cross-shaped specimen clamping end. Four pulley groups are fixedly installed on the four end faces of the frame platform, and highly lubricated bearings are set inside the pulleys.

[0007] The in-situ biaxial creep test device proposed by the present invention applies a constant creep force to a cross-shaped biaxial specimen by weights corresponding to four groups of pulley groups. The weights are connected to a fixture base through nylon lines, and the gravity of the weights is applied to the fixture group through the supporting effect of the nylon lines and the pulley groups. The fixture group transmits the gravity of the weights to the specimen through the sliding effect of the guide rail platform, so that the biaxial specimen is subjected to a constant creep force equal to the gravity of the weights; the weights of the weights at the symmetrical ends are kept consistent, so that the in-situ creep loading of the device can be ensured; by changing the weights of the two groups of symmetrical end weights, various in-situ loading forms such as equal-proportional loading and different-proportional loading of the cross-shaped biaxial specimen can be met; and in-situ uniaxial loading of the rectangular specimen can also be performed.

[0008] The in-situ biaxial creep test device proposed by the present invention has a simple overall structure, a small volume, and a low cost, and is convenient for setting up multiple devices to carry out multiple groups of creep tests simultaneously, thereby greatly reducing the cost of creep tests.

[0009] The creep test device designed in the present invention has a relatively small structural size. The entire device can be placed in an environmental test box to perform environmental control on the creep test, thereby achieving a variety of different test environments such as different temperatures, different humidity, smoke environments, light radiation environments, and rain environments. At the same time, a test environment observation window is opened on the top of the environmental box, and the deformation of the sample can be monitored in real time through an external DIC optical measurement device to obtain the creep performance parameters of the material.

[0010] The beneficial effects of the present invention are as follows:

[0011] 1. The present invention designs a simple and miniaturized in-situ biaxial creep test device, which has a simple structure, small overall size, low cost, and is convenient for mass production; at the same time, the biaxial in-situ creep loading of the thin film material sample is realized through a simple structural design, which is consistent with the actual service status of most thin film materials;

[0012] 2. The present invention controls the creep force through a special structural design combining a guide rail, a pulley block and a weight. The test device uses a nylon line to pull the weight through the pulley block and then connects to the fixture group. The gravity of the weight is then transmitted to the film material test through a highly lubricated cross roller guide rail to provide a creep force. The creep force applied to the sample can be controlled by changing the mass or quantity of the weight. This method of applying the creep force is simpler and more effective.

[0013] 3. The test device of the present invention is easy to integrate with various test environment chambers and DIC measurement devices, and can be conveniently moved to the required test environment chamber manually, thereby performing various environmental controls on the creep test; at the same time, it is combined with the DIC measurement system to synchronously monitor the creep deformation of the sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention:

[0015] Figure 1 Schematic diagram of a novel in-situ biaxial creep test device according to an embodiment of the present invention;

[0016] Figure 2 is a schematic diagram of a rack platform according to an embodiment of the present invention;

[0017] Figure 3 is a schematic diagram of a cross roller guide rail according to an embodiment of the present invention;

[0018] Figure 4 is a schematic diagram of a clamp assembly according to an embodiment of the present invention;

[0019] Figure 5 Schematic diagram of a pulley block according to an embodiment of the present invention.

[0020] Among them: 1- pulley group 2- fixture group 3- cross-shaped film material biaxial specimen 4- cross roller guide 5- rack platform 6- nylon line 7- weight 8- rack cylinder 9- base; 1-1 nut 1-2 pulley 1-3 pulley rod 1-4 pulley bracket; 2-1 fixture top cover 2-2 fixture base; 4-1 guide rail workbench 4-2 hand screw 4-3 fixing plate 4-4. Base 4-5. Cross roller; 5-1 pulley group fixing threaded hole 5-2 guide rail fixing threaded hole 5-3 countersunk hole DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme 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 only 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 should fall within the scope of protection of the present invention.

[0022] This embodiment provides a novel in-situ biaxial creep test device and test method for thin film materials. Figure 1 As shown, the test device consists of a frame body, a pulley group 1, a clamp group 2, a cross-shaped film material biaxial specimen 3, a guide rail 4, a weight 7, and a nylon line 6.

[0023] Furthermore, the frame body, as the main supporting structure of the device, is composed of a base 9, a frame cylinder 8 and a frame platform 5. Among them, countersunk holes are distributed on the frame platform 5 and the base 9, and the frame cylinder 8 is connected to the base 9 and the frame platform 5 respectively by hexagon socket screws; the slender cylindrical structure of the frame cylinder 8 can provide a handle for convenient placement and movement of the test device. Figure 2 As shown, the rack platform 5 is configured as a cross-shaped tabletop, which provides a platform path for the in-situ biaxial creep loading of the device, and can also save plate materials to the greatest extent and reduce material costs.

[0024] Furthermore, the rack platform 5 is provided with countersunk holes 5-3 connected to the rack column, threaded through holes 5-1 connected to the pulley block, and threaded through holes 5-2 connected to the guide rails; the four sets of guide rails, the fixture block, and the pulley block are symmetrically distributed at corresponding positions on the rack platform. The guide rails are cross roller driven slide rails, and the specific structural diagram is shown in FIG. Figure 3As shown, it is composed of a guide rail workbench 4-1, a hand screw 4-2, a fixing plate 4-3, a base 4-4, and a cross roller 4-5. The use of a cross roller guide rail can minimize the resistance of the workbench when sliding, and ensure the lubrication of the guide rail slide; the fixing plate 4-3 is fixed to the guide rail base 4-4 by a threaded connection, and the hand screw 4-2 is fixed to the guide rail workbench 4-1 by a threaded connection. The guide rail slide can be fixed by tightening the hand screw 4-2 to the workbench, so as to fix the guide rail slide as needed. Two threaded holes are provided on the top of the guide rail workbench, and the fixture base is provided with corresponding countersunk holes. The two can be threadedly connected and fixed by a hexagon socket bolt; in addition, the fixture base is also provided with two threaded holes, and the fixture top cover is correspondingly provided with two countersunk holes. The clamping end of the film material sample 3 is clamped and fixed by the matching connection of the fixture base and the fixture top cover.

[0025] Furthermore, four pulley blocks are respectively placed on the four end surfaces of the rack platform, and are threadedly connected and fixed through threaded holes on the rack platform 5 corresponding to the installation of the pulley blocks. Figure 5 As shown, the pulley block is mainly composed of a nut 1-1, a pulley 1-2, a pulley rod 1-3, a pulley bracket 1-4 and other components. A bearing with high lubrication accuracy is arranged inside the pulley, and the pulley bracket 1-4 is made of a bent part. The weight 7 is connected to the clamp group 2 through the conduction of the nylon line 6 and the pulley block 1. The in-situ biaxial creep test device proposed in the present invention uses weights corresponding to four groups of pulleys to apply a constant creep force to the cross-shaped biaxial specimen. The weight 7 is connected to the fixture base 2-2 through the nylon line 6. The gravity of the weight 7 is applied to the fixture group 2 through the support of the nylon line 6 and the pulley group 1. The fixture group 2 transmits the gravity of the weight 7 to the specimen through the sliding action of the guide platform, so that the biaxial specimen is subjected to a constant creep force equal to the gravity of the weight; the weights of the weights at the symmetrical ends are kept consistent, so that the in-situ creep loading of the device can be ensured; by changing the weights of the two groups of symmetrical end weights, various in-situ loading forms such as equal-proportional loading and different-proportional loading of the cross-shaped biaxial specimen can be satisfied; at the same time, in-situ uniaxial loading of rectangular specimens can also be performed. The calculation formula for the creep force on the thin film material specimen 3 is as follows:

[0026]

[0027] Among them: F 蠕 is the creep stress of the specimen; m 砝 is the mass of the weight; g is the acceleration due to gravity; S 截 is the cross-sectional area of ​​the specimen loading end.

[0028] The in-situ biaxial creep test device proposed by the present invention has a simple overall structure, a small volume, and a low cost, and is convenient for setting up multiple devices to carry out multiple groups of creep tests simultaneously, greatly reducing the cost of creep tests. Since the creep test device designed by the present invention has a relatively small structural size, the test device can be placed in an environmental test box as a whole to control the environment of the creep test, thereby realizing loading of various different test environments such as different temperatures, different humidity, salt spray environment, light radiation environment, and rain environment; at the same time, a test environment observation window is opened on the top of the environmental box, and the deformation of the sample can be monitored in real time through an external DIC optical measurement device to obtain the creep performance parameters of the material.

[0029] The embodiment of the present invention further provides a test method for a miniaturized multi-environment stress loading test device capable of online monitoring, the steps of which are as follows:

[0030] 1) First, determine the creep test specimen size of the film material, and cut out the target creep specimen size using a punching machine and a special engraving die;

[0031] 2) Select the appropriate mass of weight according to the creep test force to be determined;

[0032] 3) After adjusting the guide rail workbench to the appropriate installation position of the sample, lock the guide rail workbench and then install the sample, and hang a weight of appropriate mass at the corresponding end of the rack platform;

[0033] 4) According to the test environment requirements, the test device can be manually moved to the environmental box with the required test conditions for environmental control;

[0034] 5) Adjust the DIC equipment to ensure that the entire sample observation area is within the lens field of view;

[0035] 6) Open the locking device of the guide rail workbench synchronously to ensure that the guide rail is in a free working state and apply a constant creep force to the specimen;

[0036] 7) During this period, turn on the environmental chamber control button to synchronously control the environment to carry out the corresponding biaxial in-situ creep test.

[0037] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A novel in-situ biaxial creep test device for thin film materials, characterized in that: include: The frame body, pulley set, fixture set, guide rail, cross-shaped film material biaxial specimen, weight, nylon line; among them, The frame body is composed of a base, a frame column and a frame platform, and is the supporting structure of the device; The rack platform is configured as a cross-shaped table, and four groups of symmetrically distributed clamp groups, guide rails, and pulley groups are arranged on the rack platform; The fixture assembly consists of a fixture base and a fixture top cover, and is used to clamp a cross-shaped biaxial specimen of a thin film material; The top of the guide rail is fixedly connected to the fixture base; The nylon line pulls the weight through the pulley group and then connects with the clamp group; The gravity of the weight is transmitted to the cross-shaped biaxial test specimen of the thin film material through a highly lubricated guide rail to provide a creep force.

2. A novel in-situ biaxial creep test device for thin film materials according to claim 1, characterized in that: Countersunk holes are distributed on the rack platform and the base, and the rack cylinder is connected to the base and the rack platform respectively through hexagon socket screws.

3. A novel in-situ biaxial creep test device for thin film materials according to claim 1, characterized in that: The four sets of clamps, guide rails and pulleys are symmetrically distributed at corresponding positions on the rack platform.

4. A novel in-situ biaxial creep test device for thin film materials according to claim 3, characterized in that: The guide rail adopts a cross roller guide rail, which is composed of a guide rail workbench, hand screws, a fixing sheet, a base and cross rollers.

5. A novel in-situ biaxial creep test device for thin film materials according to claim 4, characterized in that: The fixing plate is fixed to the base of the guide rail through a threaded connection, and the hand screw is fixed to the guide rail workbench through a threaded connection. The guide rail workbench can be fixed by tightening the hand screw and the guide rail workbench.

6. A novel in-situ biaxial creep test device for thin film materials according to claim 4, characterized in that: The top of the guide rail workbench is provided with two threaded holes, and the fixture base is provided with corresponding countersunk holes, and the two can be threadedly connected and fixed by hexagon socket bolts.

7. A novel in-situ biaxial creep test device for thin film materials according to claim 1, characterized in that: The rack platform is symmetrically provided with threaded through holes connected with the pulley block and threaded through holes connected with the guide rails.

8. A test method for a novel in-situ biaxial creep test device for thin film materials according to claims 1-7, characterized in that: The following steps are involved: 1) Determine the creep test specimen size of the film material, and cut out the target creep specimen size using a punching machine and a special engraving die; 2) Select the appropriate mass of weight by the predetermined creep test force; 3) After adjusting the guide rail workbench to the appropriate installation position for the specimen, lock and fix the guide rail workbench to install the specimen; 4) Hang weights at the corresponding ends of the rack platform; 5) Adjust the DIC equipment to ensure that the entire sample observation area is within the lens field of view; 6) Open the guide rail workbench locking device synchronously to ensure that the guide rail is in a free working state and apply a constant creep force to the specimen.

9. The test method of the novel in-situ biaxial creep test device for thin film materials according to claim 8, characterized in that: According to the needs of the test environment, the test device can be placed in a sample environment box for environmental control.

10. A test method according to claim 8, characterized in that: The calculation formula of creep force on the thin film material specimen is as follows: Among them: F 蠕 is the creep stress of the specimen; m 砝 is the mass of the weight; g is the acceleration due to gravity; S 截 is the cross-sectional area of ​​the specimen loading end.

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