A device and method for measuring the dimensional stability of a material under temperature cycling based on a laser interferometer

Abstract

This invention relates to a rapid measurement device and method for material dimensional stability under temperature cycling based on a laser interferometer, belonging to the field of material physical property determination. The aim is to solve the problems of low testing efficiency and complex testing system structure in existing material dimensional stability measurements. The rapid measurement device for material dimensional stability under temperature cycling based on a laser interferometer consists of a hot-cold cycling device and an ultra-high precision dimensional measurement device. The hot-cold cycling device consists of a heating furnace and a lower cooling box. The ultra-high precision dimensional measurement device consists of a base, an air-bearing linear guide, a fixed grating, a movable grating, a laser interferometer, a data acquisition system, and a temperature control platform. This invention provides a device and method for rapidly evaluating the dimensional stability of materials under temperature cycling. Compared with the traditional method of using a thermal dilatometer for evaluating dimensional stability under hot-cold cycling, it has the advantages of shorter testing time, higher measurement accuracy, and the ability to perform hot-cold cycling processing and measurement in batches with high efficiency.

Description

Technical Field

[0001] This invention belongs to the field of physical property determination of materials, specifically relating to a rapid measurement device and method for material dimensional stability under temperature cycling based on a laser interferometer. Background Technology

[0002] Metals and metal-matrix composites, due to their high specific strength, excellent thermophysical properties, and good processability, are widely used in precision instruments, aerospace, optical systems, and high-end manufacturing. Among these applications, the dimensional stability of materials directly determines the service accuracy and reliability of components. Dimensional stability refers to the ability of a material to maintain its original shape and size without significant changes under storage (e.g., temperature cycling, long-term aging) or service conditions (e.g., overload, low-frequency vibration, shock). For high-precision components such as inertial instruments and optical mirrors, even minute dimensional changes can lead to performance failure. Therefore, establishing a testing technique that can rapidly and accurately evaluate the dimensional stability of materials under temperature cycling conditions is of great significance.

[0003] Current methods for testing the dimensional stability of materials all have their limitations and shortcomings. For example, patent US 4662955A, "Method of thermal strain hysteresis reduction in metal matrix composites," proposes to eliminate residual strain hysteresis from thermal cycling in graphite fiber reinforced aluminum matrix composites through melt treatment and low-temperature cooling (even liquid nitrogen level). However, this method still operates on a single component and does not achieve parallel and rapid testing of multiple samples. In summary, existing technologies have the following main problems:

[0004] (1) The detection efficiency is low, and the test is usually limited to a single sample, which makes it difficult to meet the needs of batch material evaluation.

[0005] (2) The device has a complex structure, high cost, and is difficult to maintain.

[0006] (3) Insufficient data acquisition and processing accuracy, making it impossible to achieve high resolution and parallel detection of multiple samples.

[0007] Therefore, there is an urgent need to develop a novel dimensional stability testing device and method based on the principle of online temperature cycling, so as to achieve parallel testing of multiple samples, simplified structure and controllable cost, and to achieve rapid, accurate and efficient evaluation of the dimensional stability of materials under temperature cycling, so as to provide a reliable evaluation means for the dimensional stability research and engineering application of metals and metal matrix composites. Summary of the Invention

[0008] To address the problems of low testing efficiency and complex testing system structure in existing methods for measuring material dimensional stability using thermal cycling, this invention proposes a rapid measurement device and method for material dimensional stability under temperature cycling based on a laser interferometer.

[0009] The present invention relates to a rapid measurement device for material dimensional stability under temperature cycling based on a laser interferometer, which consists of a thermal cycling device and an ultra-high precision dimensional measurement device.

[0010] The hot and cold circulation device consists of a heating furnace body (9) and a lower cooling box (10); the inner wall of the heating furnace body (9) is equipped with electric heating plates (12), the heating furnace body (9) is provided with a side-opening furnace door (11), the bottom of the heating furnace body (9) is provided with multiple limiting grooves (14), the bottom of the limiting grooves (14) is provided with electric baffles; the side of the heating furnace body (9) is provided with vacuum extraction holes (13); the bottom of the lower cooling box (10) is provided with a liquid storage tank (15), the liquid storage tank (15) is provided with multiple isolation chambers (16), the inlet of each isolation chamber (16) corresponds to the limiting groove (14), and the inner wall of the isolation chamber (16) is a porous structure;

[0011] The ultra-high precision dimensional measuring device consists of a base (1), an air-bearing linear guide (2), a fixed grating (3), a movable grating (4), a laser interferometer (5), a data acquisition system (6), and a temperature control platform (7). The temperature control platform (7) is mounted on the base (1), the air-bearing linear guide (2) is mounted on the temperature control platform (7), the left end of the air-bearing linear guide (2) is hinged to the temperature control platform (7), the fixed grating (3) is fixedly mounted on the upper surface of the left end of the air-bearing linear guide (2), and the right end of the air-bearing linear guide (2) is hinged to the temperature control platform (7). A spiral lifting mechanism is provided between the platforms (7). The movable grating (4) is set on the sliding seat at the right end of the air-float linear guide (2). The sliding seat is slidably installed on the track of the air-float linear guide (2). A laser interferometer (5) is provided on the side of the moving end of the air-float linear guide (2). The laser interferometer (5) is installed on the vertical lifting mechanism. The test sample (8) is provided between the fixed grating (3) and the movable grating (4). The temperature control platform (7) is made of Invar alloy. A heating wire is embedded in the temperature control platform (7).

[0012] This invention utilizes a rapid measurement device for material dimensional stability under temperature cycling based on a laser interferometer to perform a rapid measurement method for material dimensional stability. The method is characterized by the following steps:

[0013] 1. Prepare the test sample from the material to be tested (8);

[0014] II. Setting of the hot and cold cycle program for the test sample (8):

[0015] Place the test sample (8) into the limiting groove (14); set the program for the heating furnace body (9) according to the test conditions given in the test requirements; at the same time, fill the cooling medium into the downward cooling box (10) and adjust the temperature in the isolation chamber (16);

[0016] 3. Start the heating furnace (9) according to the program set in step 2 to heat the test sample (8). After the temperature and holding time are reached, open the electric baffle at the bottom of the limiting groove (14) so ​​that the test sample (8) falls into the isolation chamber (16) to cool. After completion, dry it to complete one cold and hot cycle treatment.

[0017] Fourth, adjust the temperature control platform (7) to the set temperature, which is 20℃ or 25℃, and at the same time perform wavelength calibration of the laser interferometer (5);

[0018] V. Loading and testing of the test sample (8):

[0019] First, the test sample (8) without thermal cycling treatment is placed between the fixed grating (3) and the movable grating (4). The movable grating (4) is raised using a screw lifting mechanism so that the test sample (8) is pressed onto the fixed grating (3) under the action of gravity, and the movable grating (4) is pressed onto the test sample (8) under the action of gravity. The length between the fixed grating (3) and the movable grating (4) is measured by a laser interferometer (5) and used as the initial length L0 of the test sample (8).

[0020] Then, the test sample (8) after the thermal cycling treatment is placed between the fixed grating (3) and the movable grating (4). The movable grating (4) is raised using a screw lifting mechanism so that the test sample (8) is pressed onto the fixed grating (3) under the action of gravity, and the movable grating (4) is pressed onto the test sample (8) under the action of gravity. The length between the fixed grating (3) and the movable grating (4) is measured by a laser interferometer (5) and taken as the length L of the test sample (8) after the thermal cycling treatment.

[0021] Finally, the length change rate of the test sample (8) subjected to hot and cold cycling is calculated.

[0022] The present invention has the following beneficial effects:

[0023] 1. The present invention provides a device and measurement method based on online detection of thermal cycling, which can quickly evaluate the dimensional stability of materials under temperature cycling. Compared with the traditional method of using a thermal expansion meter to evaluate dimensional stability under thermal cycling, it has the advantages of short test time, high measurement accuracy, and high-efficiency batch processing and measurement of thermal cycling.

[0024] 2. The design of the heating furnace body and the lower cooling box of this invention can perform cold and hot cycle treatment in a wider temperature range. The low temperature can reach -196℃ (liquid nitrogen temperature), and the high temperature can be flexibly selected according to the testing requirements of different materials, such as 300℃ (for aluminum alloys and aluminum-based composite materials).

[0025] 3. The ultra-high precision size measurement device of the present invention adopts the principle of coordinated measurement of dual gratings and laser interferometer to accurately measure the size of the test sample. Compared with the thermal expansion tester for evaluating the dimensional stability of materials, the present invention can significantly improve the measurement accuracy based on the micro-nano precision of the laser interferometer.

[0026] 4. In existing technologies, when evaluating the dimensional stability of materials using a thermal dilatation apparatus, liquid nitrogen is required for continuous cooling of the apparatus during the cooling stage. This process is time-consuming and consumes a large amount of liquid nitrogen, averaging 50L per sample. The isolation chamber structure designed in this invention provides thermal insulation, requiring only a small amount of liquid nitrogen for cooling the chamber, averaging 200ml to 1L per sample. Therefore, compared with the thermal dilatation apparatus method for evaluating material dimensional stability, this invention significantly reduces the consumption of cooling consumables such as liquid nitrogen, eliminates the need for environmentally harmful chemical reagents, saves energy, is more cost-effective, and is easier to industrialize and apply.

[0027] 5. The operation and measurement methods of the device of the present invention are simple and easy for operators to master. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the ultra-high precision dimension measuring device in Example 1;

[0029] Figure 2 This is a schematic diagram of the hot and cold circulation device in Example 1;

[0030] Figure 3 This is a schematic diagram of the structure of the ultra-high precision dimension measuring device after the movable grating is raised in Example 1;

[0031] Figure 4 The graph shows the length change rate of the SiCp / 2024Al composite material obtained in Example 1 after thermal cycling. Detailed Implementation

[0032] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any reasonable combination of the specific embodiments.

[0033] Specific Implementation Method 1: This implementation method is based on a rapid measurement device for material dimensional stability under temperature cycling using a laser interferometer, which consists of a thermal cycling device and an ultra-high precision dimensional measurement device.

[0034] The hot and cold circulation device consists of a heating furnace body (9) and a lower cooling box (10); the inner wall of the heating furnace body (9) is equipped with electric heating plates (12), the heating furnace body (9) is provided with a side-opening furnace door (11), the bottom of the heating furnace body (9) is provided with multiple limiting grooves (14), the bottom of the limiting grooves (14) is provided with electric baffles; the side of the heating furnace body (9) is provided with vacuum extraction holes (13); the bottom of the lower cooling box (10) is provided with a liquid storage tank (15), the liquid storage tank (15) is provided with multiple isolation chambers (16), the inlet of each isolation chamber (16) corresponds to the limiting groove (14), and the inner wall of the isolation chamber (16) is a porous structure;

[0035] The ultra-high precision dimensional measuring device consists of a base (1), an air-bearing linear guide (2), a fixed grating (3), a movable grating (4), a laser interferometer (5), a data acquisition system (6), and a temperature control platform (7). The temperature control platform (7) is mounted on the base (1), the air-bearing linear guide (2) is mounted on the temperature control platform (7), the left end of the air-bearing linear guide (2) is hinged to the temperature control platform (7), the fixed grating (3) is fixedly mounted on the upper surface of the left end of the air-bearing linear guide (2), and the right end of the air-bearing linear guide (2) is hinged to the temperature control platform (7). A spiral lifting mechanism is provided between the platforms (7). The movable grating (4) is set on the sliding seat at the right end of the air-float linear guide (2). The sliding seat is slidably installed on the track of the air-float linear guide (2). A laser interferometer (5) is provided on the side of the moving end of the air-float linear guide (2). The laser interferometer (5) is installed on the vertical lifting mechanism. The test sample (8) is provided between the fixed grating (3) and the movable grating (4). The temperature control platform (7) is made of Invar alloy. A heating wire is embedded in the temperature control platform (7).

[0036] This embodiment has the following beneficial effects:

[0037] The present invention has the following beneficial effects:

[0038] 1. The device and measurement method of this embodiment can quickly evaluate the dimensional stability of materials under temperature cycling. Compared with the traditional method of using a thermal expansion meter to evaluate dimensional stability under thermal cycling, it has the advantages of short test time, high measurement accuracy, and high-efficiency batch processing and measurement of thermal cycling.

[0039] 2. The design of the heating furnace body 9 and the lower cooling box 10 in this embodiment allows for a wider range of hot and cold cycle treatments. The low temperature can reach -196℃ (liquid nitrogen temperature), and the high temperature can be flexibly selected according to the testing requirements of different materials, such as 300℃ (for aluminum alloys and aluminum-based composite materials).

[0040] 3. The ultra-high precision size measuring device in this embodiment adopts the cooperative measurement principle of dual grating and laser interferometer 5 to accurately measure the size of the test sample 8. Compared with the thermal expansion tester for evaluating the material size stability, the present invention can significantly improve the measurement accuracy based on the micro-nano precision of the laser interferometer 5.

[0041] 4. Compared with the thermal expansion tester for evaluating the dimensional stability of materials, this method can significantly reduce the amount of cooling consumables such as liquid nitrogen, and does not require the use of environmentally harmful chemical reagents. It is energy-saving, environmentally friendly, lower in cost, and easy to achieve industrial production and application.

[0042] 5. The operation and measurement methods of the device in this embodiment are simple and easy for operators to master.

[0043] Specific Implementation Method Two: This implementation method utilizes a rapid material dimensional stability measurement device based on a laser interferometer for rapid measurement of material dimensional stability under temperature cycling. The method is characterized by the following steps:

[0044] 1. Prepare the test sample from the material to be tested (8);

[0045] II. Setting of the hot and cold cycle program for the test sample (8):

[0046] Place the test sample (8) into the limiting groove (14); set the program for the heating furnace body (9) according to the test conditions given in the test requirements; at the same time, fill the cooling medium into the downward cooling box (10) and adjust the temperature in the isolation chamber (16);

[0047] 3. Start the heating furnace (9) according to the program set in step 2 to heat the test sample (8). After the temperature and holding time are reached, open the electric baffle at the bottom of the limiting groove (14) so ​​that the test sample (8) falls into the isolation chamber (16) to cool. After completion, dry it to complete one cold and hot cycle treatment.

[0048] Fourth, adjust the temperature control platform (7) to the set temperature, which is 20℃ or 25℃, and at the same time perform wavelength calibration of the laser interferometer (5);

[0049] V. Loading and testing of the test sample (8):

[0050] First, the test sample (8) without thermal cycling treatment is placed between the fixed grating (3) and the movable grating (4). The movable grating (4) is raised using a screw lifting mechanism so that the test sample (8) is pressed onto the fixed grating (3) under the action of gravity, and the movable grating (4) is pressed onto the test sample (8) under the action of gravity. The length between the fixed grating (3) and the movable grating (4) is measured by a laser interferometer (5) and used as the initial length L0 of the test sample (8).

[0051] Then, the test sample (8) after the thermal cycling treatment is placed between the fixed grating (3) and the movable grating (4). The movable grating (4) is raised using a screw lifting mechanism so that the test sample (8) is pressed onto the fixed grating (3) under the action of gravity, and the movable grating (4) is pressed onto the test sample (8) under the action of gravity. The length between the fixed grating (3) and the movable grating (4) is measured by a laser interferometer (5) and taken as the length L of the test sample (8) after the thermal cycling treatment.

[0052] Finally, the length change rate of the test sample (8) subjected to hot and cold cycling is calculated.

[0053] 1. This embodiment of the method provides a device and measurement method based on online detection of thermal cycling, which can quickly evaluate the dimensional stability of materials under temperature cycling. Compared with the traditional method of using a thermal expansion meter to evaluate dimensional stability under thermal cycling, it has the advantages of short test time, high measurement accuracy, and high-efficiency batch processing and measurement of thermal cycling.

[0054] 2. The design of the heating furnace body 9 and the lower cooling box 10 in this embodiment allows for a wider range of hot and cold cycle treatments. The low temperature can reach -196℃ (liquid nitrogen temperature), and the high temperature can be flexibly selected according to the testing requirements of different materials, such as 300℃ (for aluminum alloys and aluminum-based composite materials).

[0055] 3. The ultra-high precision size measuring device in this embodiment adopts the cooperative measurement principle of dual grating and laser interferometer 5 to accurately measure the size of the test sample 8. Compared with the thermal expansion tester for evaluating the material size stability, the present invention can significantly improve the measurement accuracy based on the micro-nano precision of the laser interferometer 5.

[0056] 4. Compared with the thermal expansion tester for evaluating the dimensional stability of materials, this method can significantly reduce the amount of cooling consumables such as liquid nitrogen, and does not require the use of environmentally harmful chemical reagents. It is energy-saving, environmentally friendly, lower in cost, and easy to achieve industrial production and application.

[0057] 5. The operation and measurement methods of the device in this embodiment are simple and easy for operators to master.

[0058] Specific Implementation Method 3: This implementation method differs from Specific Implementation Method 2 in that the material to be tested in step one is a metallic material or a metal-based composite material.

[0059] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method Three in that the metal material is aluminum, magnesium, or titanium.

[0060] Specific Implementation Method 5: This implementation method differs from Specific Implementation Method 2 in that the shape of the test sample (8) in step 1 is a cylinder or a cuboid.

[0061] Specific Implementation Method Six: This implementation method differs from Specific Implementation Method Two in that the test conditions include atmosphere conditions, heating rate, peak temperature, and holding time.

[0062] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that: the heating rate in step two is 1-10℃ / min, the peak temperature is 80-300℃; the holding time is 0-48h; and the atmosphere is a nitrogen atmosphere, a helium atmosphere, or an argon atmosphere.

[0063] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Two in that the cooling medium in the cooling box described in step two is water, dry ice, or liquid nitrogen.

[0064] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Two in that the temperature inside the isolation chamber (16) described in step two is -196-20℃.

[0065] Specific Implementation Method 10: This implementation method differs from Specific Implementation Method 2 in that the drying temperature of the constant temperature drying oven described in step 3 is 20℃ or 25℃.

[0066] Example 1

[0067] This embodiment of the rapid measurement device for material dimensional stability under temperature cycling based on a laser interferometer consists of a thermal cycling device and an ultra-high precision dimensional measurement device.

[0068] The hot and cold circulation device consists of a heating furnace body 9 and a lower cooling box 10. The lower cooling box 10 is located at the bottom of the heating furnace body 9. Electric heating plates 12 are installed on the inner wall of the heating furnace body 9 to ensure the uniformity of the furnace temperature. The heating furnace body 9 is provided with a side-opening furnace door 11. Multiple limiting grooves 14 are provided at the bottom of the heating furnace body 9 to facilitate the rapid placement of the test sample 8. An electric baffle is provided at the bottom of the limiting groove 14. The electric baffle can open or close when receiving a control signal. After the test sample 8 is heated to the predetermined temperature in the heating furnace body 9, the electric baffle opens, and the test sample 8 enters the lower cooling box 10 by free fall. Vacuum extraction holes 13 are provided on the side of the heating furnace body 9 to flexibly adjust for different heating atmosphere conditions. A liquid storage tank 15 is provided at the bottom of the lower cooling box 10. Multiple isolation chambers 16 are provided on the liquid storage tank 15. The inlet of each isolation chamber 16 corresponds to the limiting groove 14. The inner wall of the isolation chamber 16 has a porous structure.

[0069] The ultra-high precision dimensional measuring device consists of a base 1, an air-bearing linear guide rail 2, a fixed grating 3, a movable grating 4, a laser interferometer 5, a data acquisition system 6, and a temperature control platform 7. The temperature control platform 7 is mounted on the base 1, and the air-bearing linear guide rail 2 is mounted on the temperature control platform 7. The left end of the air-bearing linear guide rail 2 is hinged to the temperature control platform 7. The fixed grating 3 is fixedly mounted on the upper surface of the left end of the air-bearing linear guide rail 2. A spiral lifting mechanism is provided between the right end of the air-bearing linear guide rail 2 and the temperature control platform 7. The movable grating 4 is mounted on a sliding seat at the right end of the air-bearing linear guide rail 2. The sliding seat is slidably mounted on the track of the air-bearing linear guide rail 2. It can achieve single-axis bidirectional displacement on the air-bearing linear guide 2; a laser interferometer 5 is set on the side of the moving end of the air-bearing linear guide 2, and the laser interferometer 5 is mounted on the vertical lifting mechanism; a test sample 8 is set between the fixed grating 3 and the movable grating 4, the fixed grating 3 serves as the reference reflective surface, the movable grating 4 serves as the basis for measuring the length of the test sample 8, the data acquisition system 6 is connected to the laser interferometer 5, and the laser interferometer 5 obtains the micro-nano-scale length of the test sample 8 by accurately measuring the distance between the movable grating 4 and the fixed grating 3; the temperature control platform 7 is made of Invar alloy, and a heating wire is embedded in the temperature control platform 7;

[0070] The rapid measurement method for material dimensional stability under temperature cycling in this embodiment is performed according to the following steps:

[0071] 1. Prepare the material to be tested into test sample 8, and polish it to remove the processing marks on the surface of test sample 8;

[0072] The material to be tested in step one is a SiCp / 2024Al composite material;

[0073] The test sample 8 mentioned in step one is cylindrical in shape; with a diameter of 6cm and a height of 25cm, there are 15 samples in total;

[0074] II. Setting the hot and cold cycling program for test sample 8:

[0075] Place the test sample 8 into the limiting groove 14; set the program for the heating furnace body 9 according to the test conditions given in the test requirements; the test conditions include atmosphere conditions, heating rate, peak temperature and holding time; at the same time, fill the cooling box 10 downwards with cooling medium and regulate the temperature in the isolation chamber 16.

[0076] The atmosphere conditions described in step two are nitrogen atmosphere; the test sample 8 is protected under a protective atmosphere to avoid changes in material dimensional stability caused by high-temperature oxidation.

[0077] The heating rate in step two is 5℃ / min, the peak temperature is 80℃, and the holding time is 5min.

[0078] The cooling medium in the cooling box described in step two is dry ice;

[0079] Step two describes adjusting the temperature inside the isolation chamber 16 to -40℃;

[0080] III. Hot and cold circulation treatment:

[0081] According to the hot and cold cycle program set in step two, the heating furnace body 9 is started to heat the test sample 8. After the temperature and holding time are reached, the electric baffle at the bottom of the limiting groove 14 is opened, allowing the test sample 8 to fall freely into the isolation chamber 16 of the lower cooling box 10. After the test sample 8 has cooled down, it is taken out from the isolation chamber 16 and placed in a constant temperature drying oven for drying, thus completing one hot and cold cycle treatment.

[0082] The drying temperature of the constant temperature drying oven described in step three is 20℃;

[0083] IV. Start-up and initialization of the ultra-high precision dimensional measuring device:

[0084] Adjust the temperature control platform 7 to the set temperature, and simultaneously perform wavelength calibration on the laser interferometer 5;

[0085] The set temperature of the temperature control platform 7 described in step four is 20℃;

[0086] V. Loading and testing of sample 8:

[0087] First, the test sample 8, which has not undergone thermal cycling, is placed between the fixed grating 3 and the movable grating 4. The movable grating 4 is raised using a spiral lifting mechanism located between the right end of the air-bearing linear guide 2 and the temperature control platform 7, so that the test sample 8 is pressed onto the fixed grating 3 under gravity, while the movable grating 4 is pressed onto the test sample 8 under gravity, thus achieving contact between the test sample 8 and the movable grating 4. The length between the fixed grating 3 and the movable grating 4 is measured using a laser interferometer 5. This measurement is repeated multiple times, and the average value of the obtained length values ​​is taken as the initial length L0 of the test sample 8.

[0088] Then, the test sample 8 after the thermal cycling treatment is placed between the fixed grating 3 and the movable grating 4. The movable grating 4 is raised by the spiral lifting mechanism set between the right end of the air-bearing linear guide 2 and the temperature control platform 7, so that the test sample 8 is pressed on the fixed grating 3 under the action of gravity, and at the same time, the movable grating 4 is pressed on the test sample 8 under the action of gravity, so that the test sample 8 and the movable grating 4 are in contact. The length between the fixed grating 3 and the movable grating 4 is measured by the laser interferometer 5. The measurement is repeated many times, and the average value of the obtained length values ​​is taken as the length L of the test sample 8 after multiple thermal cycling treatments.

[0089] Finally, the rate of change in length of the test sample 8 after the hot and cold cycling treatment was calculated.

[0090] The measurement principle in this embodiment is as follows:

[0091] A laser interferometer is used to measure displacement, calculating the distance moved by observing changes in interference fringes. A fixed grating serves as an optical reference; a movable grating is connected to the sample and moves with the sample's length. Based on the principle of light interference, the interference fringes shift as the movable grating moves. Each complete bright-to-dark-to-bright cycle of fringe movement corresponds to a change in optical path length of one wavelength λ, and the corresponding actual displacement is half of this change.

[0092]

[0093] If the stripes have shifted by N cycles, the total displacement is:

[0094]

[0095] When the length of the sample changes, the movable grating moves accordingly, causing the interference fringes to drift. By recording the number of fringe shifts, N, the laser interferometer can accurately calculate the displacement of the movable grating, thus obtaining the change in sample length.

[0096] Figure 1 This is a schematic diagram of the ultra-high precision dimension measuring device in Example 1; Figure 2 This is a schematic diagram of the hot and cold circulation device in Example 1; Figure 3 This is a schematic diagram of the structure of the movable grating 4 of the ultra-high precision dimension measuring device in Example 1 after it has been raised.

[0097] The dimensional stability of the SiCp / 2024Al composite material was tested according to Example 1. A single thermal cycling treatment of 15 samples took 35 minutes, significantly improving efficiency compared to the traditional thermal dilatation apparatus method. Figure 4 The graph shows the length change rate of the SiCp / 2024Al composite material obtained in Example 1 after thermal cycling. It also shows the dimensional measurement results of 15 samples after thermal cycling at -40°C and 80°C. The measured dimension L is subtracted from the initial dimension L0 to obtain dL, which is then compared to L0 to obtain a value of 10. -6 The magnitude indicates that the accuracy of the test results obtained using the device and testing method of this embodiment is at the submicron scale, which can meet the current testing requirements for low cost, high efficiency and high accuracy of material dimensional stability testing.

Claims

1. A rapid measurement device for material dimensional stability under temperature cycling based on a laser interferometer, characterized in that: The rapid measurement device for material dimensional stability under temperature cycling based on laser interferometer consists of a hot and cold cycling device and an ultra-high precision dimensional measurement device. The hot and cold circulation device consists of a heating furnace body (9) and a lower cooling box (10); the inner wall of the heating furnace body (9) is equipped with electric heating plates (12), the heating furnace body (9) is provided with a side-opening furnace door (11), the bottom of the heating furnace body (9) is provided with multiple limiting grooves (14), the bottom of the limiting grooves (14) is provided with electric baffles; the side of the heating furnace body (9) is provided with vacuum extraction holes (13); the bottom of the lower cooling box (10) is provided with a liquid storage tank (15), the liquid storage tank (15) is provided with multiple isolation chambers (16), the inlet of each isolation chamber (16) corresponds to the limiting groove (14), and the inner wall of the isolation chamber (16) is a porous structure; The ultra-high precision dimensional measuring device consists of a base (1), an air-bearing linear guide (2), a fixed grating (3), a movable grating (4), a laser interferometer (5), a data acquisition system (6), and a temperature control platform (7). The temperature control platform (7) is mounted on the base (1), the air-bearing linear guide (2) is mounted on the temperature control platform (7), the left end of the air-bearing linear guide (2) is hinged to the temperature control platform (7), the fixed grating (3) is fixedly mounted on the upper surface of the left end of the air-bearing linear guide (2), and the right end of the air-bearing linear guide (2) is hinged to the temperature control platform (7). A spiral lifting mechanism is provided between the platforms (7). The movable grating (4) is set on the sliding seat at the right end of the air-float linear guide (2). The sliding seat is slidably installed on the track of the air-float linear guide (2). A laser interferometer (5) is provided on the side of the moving end of the air-float linear guide (2). The laser interferometer (5) is installed on the vertical lifting mechanism. The test sample (8) is provided between the fixed grating (3) and the movable grating (4). The temperature control platform (7) is made of Invar alloy. A heating wire is embedded in the temperature control platform (7).

2. A method for rapidly measuring the dimensional stability of materials using the rapid measurement device for material dimensional stability under temperature cycling based on a laser interferometer as described in claim 1, characterized in that: This method is performed according to the following steps:

1. Prepare the test sample from the material to be tested (8); II. Setting of the hot and cold cycle program for the test sample (8): Place the test sample (8) into the limiting groove (14); set the program for the heating furnace body (9) according to the test conditions given in the test requirements; at the same time, fill the cooling medium into the downward cooling box (10) and adjust the temperature in the isolation chamber (16); 3. Start the heating furnace (9) according to the program set in step 2 to heat the test sample (8). After the temperature and holding time are reached, open the electric baffle at the bottom of the limiting groove (14) so ​​that the test sample (8) falls into the isolation chamber (16) to cool. After completion, dry it to complete one cold and hot cycle treatment. Fourth, adjust the temperature control platform (7) to the set temperature, which is 20℃ or 25℃, and at the same time perform wavelength calibration of the laser interferometer (5); V. Loading and testing of the test sample (8): First, the test sample (8) without thermal cycling treatment is placed between the fixed grating (3) and the movable grating (4). The movable grating (4) is raised using a screw lifting mechanism so that the test sample (8) is pressed onto the fixed grating (3) under the action of gravity, and the movable grating (4) is pressed onto the test sample (8) under the action of gravity. The length between the fixed grating (3) and the movable grating (4) is measured by a laser interferometer (5) and used as the initial length L0 of the test sample (8). Then, the test sample (8) after the thermal cycling treatment is placed between the fixed grating (3) and the movable grating (4). The movable grating (4) is raised using a screw lifting mechanism so that the test sample (8) is pressed onto the fixed grating (3) under the action of gravity, and the movable grating (4) is pressed onto the test sample (8) under the action of gravity. The length between the fixed grating (3) and the movable grating (4) is measured by a laser interferometer (5) and taken as the length L of the test sample (8) after the thermal cycling treatment. Finally, the length change rate of the test sample (8) subjected to hot and cold cycling is calculated.

3. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling as described in claim 2, characterized in that: The material to be tested in step one is a metallic material or a metal-based composite material.

4. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling as described in claim 3, characterized in that: The metallic material is aluminum, magnesium, or titanium.

5. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling as described in claim 2, characterized in that: The test sample (8) described in step one is cylindrical or cuboid in shape.

6. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling as described in claim 2, characterized in that: The test conditions include atmospheric conditions, heating rate, peak temperature, and holding time.

7. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling as described in claim 6, characterized in that: The heating rate in step two is 1-10℃ / min, the peak temperature is 80-300℃, the holding time is 0-48h, and the atmosphere is nitrogen, helium, or argon.

8. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling as described in claim 2, characterized in that: The cooling medium in the cooling tank described in step two is water, dry ice, or liquid nitrogen.

9. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling as described in claim 2, characterized in that: Step 2 describes adjusting the temperature inside the isolation chamber (16) to -196-20℃.

10. The method for rapidly measuring material dimensional stability using a rapid material dimensional stability measurement device based on a laser interferometer under temperature cycling according to claim 2, characterized in that: Step 3: The drying temperature of the constant temperature drying oven is 20℃ or 25℃.

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