Shell and rock test piece mold

Abstract

The invention discloses a shell and a rock test piece mold, and the shell is obtained according to the following preparation method steps: uniformly mixing modified polyether-ether-ketone granules, carbon fibers and an antioxidant, performing injection molding to form a shell blank, and spraying a polytetrafluoroethylene layer on the inner wall of the shell blank to obtain the shell; the material formula and the structural design are improved at the same time, so that the mechanical property of the shell is greatly improved, the heat exchange efficiency of the shell is improved, the heat-conducting property of the shell is improved, the durability and stability of the shell are enhanced, the service life of the mold is prolonged, and the shell meets the use requirements of the rock test piece mold under the complex working conditions and also meets the requirements of the rock test piece mold under the complex working conditions. And more research and production possibilities are provided for users.

Description

Technical Field

[0001] The present invention relates to the technical field of mold manufacturing, and specifically to a housing and a rock specimen mold. Background Art

[0002] With the rapid development of the fields of geological engineering, oil exploration, and materials science, the forming technology of high-temperature and high-pressure rock specimens has become a research hotspot. During the preparation of rock specimens, the performance of the mold is crucial for the accuracy and reliability of experimental results. Due to the multiple tests of high temperature, high pressure, and complex chemical environments, the housing of traditional rock specimen molds is extremely prone to oxidation and deformation. This not only damages the dimensional accuracy of the mold, thereby affecting the forming quality of rock specimens, but also greatly shortens the service life of the mold and increases the experimental cost. In addition, the low heat exchange efficiency of the housing of traditional rock specimen molds results in a large temperature difference between the inside and outside of the housing, unable to provide a stable and uniform temperature environment for the preparation of rock specimens, seriously interfering with the accuracy of experimental data. Summary of the Invention

[0003] To solve the above problems, one of the purposes of the present invention is to provide a housing, which is obtained according to the following preparation method steps: Mix 81 - 89 parts of modified polyetheretherketone pellets, 10 - 16 parts of carbon fiber, and 1 - 3 parts of antioxidant Irganox 1010 evenly, and then injection mold them into a shell embryo. Spray a polytetrafluoroethylene layer on the inner wall of the shell embryo to obtain the finished product; spraying the polytetrafluoroethylene layer can significantly reduce the friction between the rock specimen and the housing, making the demolding process smoother and reducing the risk of specimen damage; at the same time, polytetrafluoroethylene also has good chemical stability and corrosion resistance, which can protect the inner wall of the housing from being eroded by rock specimens or other chemical substances; The preparation method of the modified polyetheretherketone pellets includes the following steps: Mix 53 - 67 parts of polyetheretherketone resin, 12 - 16 parts of nano silicon carbide particles, 10 - 14 parts of nano titanium dioxide, 5 - 9 parts of diphenylmethane diisocyanate, and 6 - 8 parts of triphenylphosphine evenly, and then put them into a twin-screw extruder for melt blending and extrusion to obtain modified polyetheretherketone pellets.

[0004] Preferably, during the injection molding process of the double-layer hollow housing, the temperatures of each zone of the injection molding machine are as follows: the temperature of the first zone is 370 - 380 °C, the temperature of the second zone is 380 - 390 °C, and the temperature of the third zone is 390 - 400 °C. Gradually increasing the temperature of each zone can ensure that the material is fully melted to form a uniform double-layer structure. The injection pressure is 100 - 120 MPa, the holding pressure is 60 - 80 MPa, and the holding time is 10 - 15 seconds. Appropriate pressure can make the material more compact, avoid the appearance of bubbles, and ensure the integrity of the housing structure.

[0005] Preferably, the screw speed of the twin-screw extruder is 250 - 350 r / min to ensure sufficient mixing of materials without excessive shearing. The temperatures of each zone of the twin-screw extruder are as follows: the temperature of the first zone is 360 - 370 °C, the temperature of the second zone is 370 - 380 °C, the temperature of the third zone is 380 - 390 °C, the temperature of the fourth zone is 390 - 400 °C, and the temperature of the die head is 400 - 410 °C.

[0006] Preferably, before spraying the polytetrafluoroethylene layer, the inner wall of the double-layer hollow shell is lightly polished to remove burrs, and then cleaned with ethanol to remove oil stains, so that the sprayed polytetrafluoroethylene layer adheres more firmly. After spraying, the double-layer hollow shell is placed in a curing furnace, heated at a heating rate of 3 - 7 °C / min to 370 - 380 °C, and kept at this temperature for 1 - 2 hours, and then cooled to room temperature with the furnace, so that the polytetrafluoroethylene coating is fully cured. Slowly heating and constant-temperature curing can reduce the internal stress in the coating and avoid coating cracking, and slow cooling can further stabilize the coating structure and improve the coating durability.

[0007] Preferably, the thickness of the polytetrafluoroethylene layer is 0.1 - 0.2 mm. Too thick a coating leads to increased costs, while too thin a coating fails to achieve the expected protection and demoulding effects.

[0008] Preferably, the shell is a double-layer hollow structure with a spiral water channel inside. The shell has a through shell inner space, and the double-layer hollow shell is also provided with an integrally formed first through hole, and the first through hole communicates with the shell inner space.

[0009] The second object of the present invention is to provide a rock specimen mold, including: A base; The shell obtained by the preparation method according to claim 1, which is arranged on the base and magnetically connected to the base. The spiral water channel in the shell passes through circulating coolant, and the circulating coolant is water or ethylene glycol, and the circulating coolant is connected by an external circulation pump; and The through plate member sequentially passes through the first through hole, the shell inner space and the first through hole on the other side.

[0010] Preferably, an electromagnet is installed on the base, and the electromagnet is connected to a power supply. A permanent magnet is installed at the bottom of the shell, and the polarity of the electromagnet is opposite to the polarity of the permanent magnet. When the electromagnet is energized, the magnetic field generated by the electromagnet interacts with the magnetic field of the permanent magnet to realize the magnetic connection between the base and the shell. When the electromagnet is de-energized, the magnetic field disappears and the magnetic connection is released.

[0011] Preferably, a micro vibrator is provided at the bottom of the base to improve the uniformity of pore filling.

[0012] Preferably, a detachable baffle is attached to the inner wall of the shell, a second through hole is provided on the baffle, a texture is provided on the surface of the baffle, the position of the second through hole corresponds to the position of the first through hole, and the two have different shapes, and the first through hole and the second through hole are partially overlapped by adjusting the position of the baffle to form through holes of different shapes, and the through-plate member passes through the first through hole, the second through hole, the space inside the shell and the first through hole and the second through hole on the other side in sequence, and the cross-sectional area of ​​the through-plate member is consistent with the shape of the through hole. By replacing the baffle, the size and shape of the through hole can be changed, and the mold can be made into pores of more shapes, enriching the pore morphology of the rock specimen and providing rock specimens with pores of various shapes; at the same time, replacing the baffle can also change the texture style, so that users can simulate the surface texture of different rocks and make the rock specimen closer to the actual geological sample.

[0013] The beneficial effects are: This application achieves comprehensive optimization of the rock specimen mold shell in terms of performance, function and application range through innovative material formulation and structural design.

[0014] First, the mechanical properties of the mold shell were optimized by formula improvement: by introducing reinforcing phases such as carbon fiber, nano silicon carbide particles and nano titanium dioxide, combined with the excellent matrix properties of polyetheretherketone resin, a multiphase reinforcement system was successfully constructed. Carbon fiber provides high strength and modulus, while nano silicon carbide particles and nano titanium dioxide fill the matrix at a microscopic scale, further optimizing the rigidity and strength of the shell. At the same time, diphenylmethane diisocyanate and polyetheretherketone resin undergo cross-linking reaction to form a three-dimensional network structure, which not only significantly enhances the mechanical properties of the shell, but also anchors nano silicon carbide particles and nano titanium dioxide in the three-dimensional network structure, ensuring the uniformity of the components of each part of the shell. This uniformity enables the molded shell to maintain structural stability during the casting process and improves the reliability of the mold; triphenylphosphine, as a catalyst and compatibility improver, not only accelerates the cross-linking reaction, but also optimizes the dispersion effect of inorganic fillers, making the synergistic effect between each reinforcing phase and the matrix more significant. This synergistic reinforcement mechanism enables the shell to exhibit excellent tensile, bending and impact resistance when subjected to external loads, and can effectively meet the mechanical requirements of the rock specimen mold under complex working conditions.

[0015] Secondly, the thermal conductivity of the mold shell is improved through formula improvement: the high thermal conductivity of carbon fiber and nano-silicon carbide particles, combined with the optimization of the heat conduction path by nano-titanium dioxide, forms an efficient heat conduction network. This synergistic effect not only improves the thermal conductivity of the shell, but also makes the heat distribution inside the shell more uniform, effectively reducing the generation of thermal stress. During the injection molding process, uniform heat distribution helps to improve molding quality and reduce defects caused by uneven temperature; during use, good thermal stability ensures the size and performance of the shell in a high temperature environment, extending the service life of the shell.

[0016] Furthermore, the durability of the mold housing is enhanced through formulation improvement: The addition of antioxidants effectively inhibits the oxidative degradation of polyetheretherketone resin and other components during processing and use, extending the service life of the housing. The ultraviolet absorption ability of nano-titanium dioxide further improves the weather resistance of the housing, significantly enhancing the performance stability in ultraviolet environments such as outdoors. In addition, the spraying of polytetrafluoroethylene coating not only significantly reduces the friction between the rock specimen and the housing, simplifies the demolding process, and reduces the risk of specimen damage, but also provides chemical protection for the inner wall of the housing to prevent the chemical substances in the specimen from eroding the housing. This mechanism of enhancing durability through internal and external coordination enables the housing to adapt to various complex usage environments, further expanding its application scope.

[0017] Finally, the stability of the mold housing is improved through structural improvement: By setting a spiral water channel with circulating cooling liquid inside the double-layer hollow structure of the housing, heat can be quickly exported through forced convection, effectively alleviating the accumulation of thermal stress inside the housing and avoiding deformation of the housing caused by local overheating. In addition, the synergistic effect of the spiral water channel and the double-layer hollow structure forms a temperature-equalizing structure, further reducing the thermal stress caused by the temperature difference between the inside and outside of the housing and significantly reducing the risk of housing cracking. The design of the spiral water channel not only optimizes the thermal performance of the housing structurally but also brings significant benefits in terms of process. By quickly exporting heat, the spiral water channel can achieve rapid cooling of the housing, thereby shortening the curing cycle of the rock specimen and significantly improving production efficiency. In addition, this design also provides conditions for users to simulate low-temperature environments, enabling users to study the mechanical properties and physical characteristics of rock specimens at different temperatures.

[0018] In summary, through the simultaneous improvement of material formulation and structural design in this application, the mechanical properties of the housing are greatly improved, the heat exchange efficiency of the housing is increased, the heat conduction performance of the housing is improved, the durability and stability of the housing are enhanced, the service life of the mold is extended, and the housing not only meets the usage requirements of the rock specimen mold under complex working conditions but also provides more possibilities for users to conduct research and production. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments and descriptions thereof of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings: Figure 1 It is a schematic diagram of the explosion structure of the present invention; In the figure: 1. Base; 11. Groove; 12. Miniature vibrator; 2. Housing; 21. First through-hole; 3. Plate-piercing member. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] The present invention will be further described in detail below in conjunction with specific embodiments, so that those skilled in the art can understand the present invention more clearly.

[0021] The following embodiments are only used to illustrate the present invention, but are not intended to limit the scope of the present invention. Based on the specific embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the protection scope of the present invention.

[0022] In the embodiments of the present invention, unless otherwise specified, all raw material components are commercially available products well-known to those skilled in the art; in the embodiments of the present invention, unless specifically specified, the technical means used are conventional means well-known to those skilled in the art.

[0023] Source of raw materials: Carbon fiber, purchased from Dongguan Yisike Plastic Co., Ltd.; Antioxidant Irganox 1010, purchased from Suzhou Jingyan New Materials Co., Ltd.; Polytetrafluoroethylene, purchased from Jiangsu Tianwen New Materials Technology Co., Ltd.; Polyetheretherketone resin, purchased from Dongguan Aohua Plastic Trade Co., Ltd.; Nanoscale silicon carbide particles, purchased from Hangzhou Jikang New Materials Co., Ltd.; Nanoscale titanium dioxide, purchased from Guangzhou Yinuo Chemical Technology Co., Ltd.; Diphenylmethane diisocyanate, purchased from Shandong Shengteng Chemical Co., Ltd.; Triphenylphosphine, purchased from Jinan Quansheng Chemical Co., Ltd.; The remaining reagents are all conventional commercial products.

[0024] Example 1 This example provides a method for preparing a shell, which includes the following steps: 89 parts of modified polyetheretherketone pellets, 10 parts of carbon fiber, and 1 part of antioxidant Irganox 1010 were mixed evenly and then put into an injection molding machine. The temperatures of each zone of the injection molding machine were as follows: the temperature of the first zone was 370 °C, the temperature of the second zone was 380 °C, the temperature of the third zone was 390 °C, the injection pressure was 100 MPa, the holding pressure was 60 MPa, and the holding time was 10 seconds. It was injection molded by the injection molding machine into a double-layer hollow shell with a spiral water channel inside. The shell also had a through shell internal space. A first through hole was integrally formed on the double-layer hollow shell, and the first through hole communicated with the shell internal space. After the shell was cooled and formed, the inner wall of the double-layer hollow shell was lightly polished to remove burrs, then cleaned with ethanol to remove oil stains, and then a 0.1 mm thick polytetrafluoroethylene layer was sprayed on the inner wall of the double-layer hollow shell. After the spraying was completed, the double-layer hollow shell was put into a curing furnace, heated to 370 °C at a heating rate of 3 °C / min, and held at this temperature for 1 hour, and then cooled to room temperature with the furnace to fully cure the polytetrafluoroethylene coating to obtain the shell; The preparation method of the modified polyetheretherketone pellets includes the following steps: 67 parts of polyetheretherketone resin, 12 parts of nano silicon carbide particles, 10 parts of nano titanium dioxide, 5 parts of diphenylmethane diisocyanate, and 6 parts of triphenylphosphine were mixed evenly and then put into a twin-screw extruder for melt blending and then extruded to obtain modified polyetheretherketone pellets. The screw speed of the twin-screw extruder was 250 r / min. The temperatures of each zone of the twin-screw extruder were as follows: the temperature of the first zone was 360 °C, the temperature of the second zone was 370 °C, the temperature of the third zone was 380 °C, the temperature of the fourth zone was 390 °C, and the head temperature was 400 °C.

[0025] Please refer to the appendix Figure 1 , this embodiment also provides a rock specimen mold, including: A base 1, on which an electromagnet is installed. The electromagnet is connected to a power supply. A permanent magnet is installed at the bottom of the shell 2. The polarity of the electromagnet is opposite to the polarity of the permanent magnet. When the electromagnet is energized, the magnetic field generated by the electromagnet interacts with the magnetic field of the permanent magnet to realize the magnetic connection between the base 1 and the shell 2. When the electromagnet is de-energized, the magnetic field disappears and the magnetic connection is released; A micro vibrator 12 is provided at the bottom of the base 1 to improve the uniformity of pore filling; The housing 2 obtained according to the above preparation method is arranged on the base 1 and magnetically connected to the base 1. A circulating coolant passes through the spiral water channel of the housing 2. The circulating coolant is water or ethylene glycol and is connected by an external circulating pump. A detachable baffle is attached to the inner wall of the housing 2. The baffle is provided with a second through hole, and the surface of the baffle is provided with a texture. The position of the second through hole corresponds to the position of the first through hole 21, and the two have different shapes. By adjusting the position of the baffle, the first through hole 21 and the second through hole are partially overlapped to form through holes of different shapes. The through plate member 3 sequentially passes through the first through hole 21, the second through hole, the inner space of the housing and the first through hole 21 and the second through hole on the other side. The cross-sectional area of the through plate member 3 is consistent with the shape of the through hole. By replacing the baffle, the size and shape of the through hole can be changed, enabling the mold to produce pores of more shapes, enriching the pore morphology of the rock specimens, and providing rock specimens with pores of various shapes. At the same time, replacing the baffle can also change the texture style so that users can simulate the surface textures of different rocks and make the rock specimens closer to actual geological samples.

[0026] Example 2 The difference between this embodiment and Embodiment 1 is that this embodiment provides a method for preparing a housing, which includes the following steps: 85 parts of modified polyether ether ketone pellets, 13 parts of carbon fiber, and 2 parts of antioxidant Irganox 1010 are mixed evenly and then put into an injection molding machine. The temperatures of each zone of the injection molding machine are: the temperature of the first zone is 375 °C, the temperature of the second zone is 385 °C, the temperature of the third zone is 395 °C, the injection pressure is 110 MPa, the holding pressure is 70 MPa, and the holding time is 13 seconds. It is injection molded by the injection molding machine into a double-layer hollow housing with a spiral water channel. The housing also has a through inner space, and an integrally formed first through hole is also provided on the double-layer hollow housing. The first through hole communicates with the inner space of the housing. After the housing is cooled and formed, the inner wall of the double-layer hollow housing is lightly polished to remove burrs, and then cleaned with ethanol to remove oil stains. Then, a polytetrafluoroethylene layer with a thickness of 0.15 mm is sprayed on the inner wall of the double-layer hollow housing. After spraying, the double-layer hollow housing is put into a curing furnace, heated to 375 °C at a heating rate of 5 °C / min, and kept at this temperature for 1.5 hours, and then cooled to room temperature with the furnace to fully cure the polytetrafluoroethylene coating to obtain the housing; The preparation method of the modified polyether ether ketone pellets includes the following steps: 60 parts of polyether ether ketone resin, 14 parts of nano silicon carbide particles, 12 parts of nano titanium dioxide, 7 parts of diphenylmethane diisocyanate, and 7 parts of triphenylphosphine are mixed evenly and then put into a twin-screw extruder for melt blending and extrusion to obtain modified polyether ether ketone pellets. The screw speed of the twin-screw extruder is 300 r / min. The temperatures of each zone of the twin-screw extruder are: the temperature of the first zone is 365 °C, the temperature of the second zone is 375 °C, the temperature of the third zone is 385 °C, the temperature of the fourth zone is 395 °C, and the temperature of the die head is 405 °C.

[0027] Example 3 The difference between this example and Example 1 is that this example provides a method for preparing a shell, which includes the following steps: Mix 81 parts of modified polyetheretherketone pellets, 16 parts of carbon fiber, and 3 parts of antioxidant Irganox 1010 evenly, and then put them into an injection molding machine. The temperatures of each zone of the injection molding machine are as follows: the temperature of the first zone is 380 °C, the temperature of the second zone is 390 °C, the temperature of the third zone is 400 °C, the injection pressure is 120 MPa, the holding pressure is 80 MPa, and the holding time is 15 seconds; Inject through the injection molding machine to form a double-layer hollow shell with a spiral water channel inside. The shell also has a penetrating inner space. The double-layer hollow shell is also provided with an integrally formed first through hole, and the first through hole communicates with the inner space; After the shell is cooled and formed, lightly polish the inner wall of the double-layer hollow shell to remove burrs, then clean it with ethanol to remove oil stains, and then spray a 0.2 mm thick polytetrafluoroethylene layer on the inner wall of the double-layer hollow shell. After spraying, put the double-layer hollow shell into a curing furnace, heat it up to 380 °C at a heating rate of 7 °C / min, and keep it at this temperature for 2 hours, and then cool it to room temperature with the furnace to fully cure the polytetrafluoroethylene coating to obtain the shell; The preparation method of the modified polyetheretherketone pellets includes the following steps: Mix 53 parts of polyetheretherketone resin, 16 parts of nano silicon carbide particles, 14 parts of nano titanium dioxide, 9 parts of diphenylmethane diisocyanate, and 8 parts of triphenylphosphine evenly, and then put them into a twin-screw extruder for melt blending and extrusion to obtain modified polyetheretherketone pellets; The screw speed of the twin-screw extruder is 350 r / min, and the temperatures of each zone of the twin-screw extruder are as follows: the temperature of the first zone is 370 °C, the temperature of the second zone is 380 °C, the temperature of the third zone is 390 °C, the temperature of the fourth zone is 400 °C, and the temperature of the die head is 410 °C.

[0028] Comparative Example 1 The difference between this comparative example and Example 2 is that when preparing the shell, 85 parts of polyetheretherketone pellets are used to replace 85 parts of modified polyetheretherketone pellets, and other components and experimental steps are the same as those in Example 2.

[0029] Comparative Example 2 The difference between this comparative example and Example 2 is that when preparing the shell, the amount of 85 parts of modified polyetheretherketone pellets is increased to 98 parts and no carbon fiber is added, and other components and experimental steps are the same as those in Example 2.

[0030] Comparative Example 3 The difference between this comparative example and Example 2 is that when preparing the modified polyetheretherketone pellets, the amount of 60 parts of polyetheretherketone resin is increased to 67 parts and no diphenylmethane diisocyanate is added, and other components and experimental steps are the same as those in Example 2.

[0031] Comparative Example 4 The difference between this comparative example and Example 2 is that when preparing the modified polyetheretherketone pellets, the amount of polyetheretherketone resin is increased from 60 parts to 86 parts, and no nano silicon carbide particles and nano titanium dioxide are added. Other components and experimental procedures are the same as those in Example 2.

[0032] Comparative Example 5 The difference between this comparative example and Example 2 is that no spiral water channels are provided in the double-layer hollow shell of this comparative example.

[0033] The rock specimen molds prepared in Examples 1 - 3 and Comparative Examples 1 - 5 were tested.

[0034] Test method: Mechanical property detection: The heat resistance fatigue performance of the mold shell was tested. A thermal cycle loading test was used, cycling a certain number of times (such as 1000 - 2000 times) between high temperature (such as 250 - 300 °C) and room temperature, observing whether failure phenomena such as cracks and deformations occurred in the mold shell, and testing the changes in mechanical properties such as tensile strength and flexural strength.

[0035] Heat resistance fatigue performance detection: A heat fatigue testing machine was used to conduct heat resistance fatigue testing on the mold shell. The mold shell was heated to 600 °C, held for 10 min, and then rapidly cooled to room temperature, cycling 5000 times. Observe whether defects such as cracks and deformations appear on the surface of the mold shell, and evaluate its heat resistance fatigue performance.

[0036] Coating adhesion detection: The adhesion between the TiN coating and the mold substrate was detected by the scratch test method. A scratching instrument was used to scratch on the coating surface, applying a gradually increasing load, observing the critical load when the coating peeled off. The critical load should not be less than 50 N to ensure good adhesion of the coating.

[0037] Demolding performance detection: Through multiple pouring and demolding tests, the demolding success rate and average demolding force were statistically analyzed. The demolding success rate should not be less than 95%, and the average demolding force should be within a reasonable range to ensure good demolding performance of the mold.

[0038] Table 1 Test results of the performance of the rock specimen mold

[0039] It can be found from the experimental data in Table 1 that all performance indicators in Examples 1 to 3 of this application are superior to those of the comparative examples. Among them, the tensile strength of the three groups of examples reaches above 170, and the flexural strength reaches above 200, indicating that the mechanical properties of each example are excellent. The coating adhesion is higher than 50 N, and the polytetrafluoroethylene coating is firmly bonded to the shell, indicating that the demolding success rate reaches above 95%, and the average demolding force is only 145 - 150 N, indicating that the shell is easy to demold. The circulating cooling efficiency reaches above 80%, indicating good cooling effect. The number of heat-resistant fatigue cycles can reach 5000 times without cracks or deformation, indicating that the shell has excellent heat-resistant fatigue performance. Further analysis and comparison can also find that the performance of Example 2 among the three groups of examples is the best. This may be because the ratio of each component and the setting of process parameters in Example 2 reach an ideal balance state.

[0040] Continuing the comparative analysis of the data of Example 1 and the comparative examples, it is found that in the preparation of the housing in Comparative Example 1, when 85 parts of polyether ether ketone pellets were replaced with 85 parts of modified polyether ether ketone pellets, the tensile strength and flexural strength of the housing both decreased. This may be because compared with the modified polyether ether ketone pellets, the pure polyether ether ketone pellets cannot form a three-dimensional network structure and lack components such as nanoparticles, resulting in a decrease in the mechanical properties of the housing. And the coating adhesion also decreased. This may be because the modified polyether ether ketone pellets in the example contain nanoparticles that can increase the surface roughness of the housing and provide more mechanical anchor points for the polytetrafluoroethylene coating, thus making the coating bind more firmly; while Comparative Example 1 lacks these nanoparticles, resulting in the coating being more likely to fall off. Since the coating falling off may further lead to a decrease in the demolding success rate and an increase in the average demolding force; in addition, the circulating cooling efficiency and the number of heat-resistant fatigue cycles of Comparative Example 1 also both decreased. This may be because Comparative Example 1 uses pure polyether ether ketone pellets and lacks nano silicon carbide particles and nano titanium dioxide, so that the housing cannot conduct heat efficiently and cannot cooperate with the spiral water channel to take out the heat from the housing. In Comparative Example 2, when preparing the housing, the amount of 85 parts of modified polyether ether ketone pellets was increased to 98 parts and no carbon fiber was added, resulting in a significant decrease in the mechanical properties of the housing. This may be because relying solely on the modified polyether ether ketone pellets and lacking the bridging effect and axial rigid support effect of carbon fiber, it is easy to enhance the brittleness of the housing, resulting in a decrease in both tensile strength and flexural strength. And the lack of carbon fiber also blocks the heat conduction path of the housing, resulting in a decrease in both the circulating cooling efficiency and the number of heat-resistant fatigue cycles. In Comparative Example 3, when preparing the modified polyether ether ketone pellets, the amount of 60 parts of polyether ether ketone resin was increased to 67 parts and no diphenylmethane diisocyanate was added, resulting in the housing being unable to form a three-dimensional network structure and further anchor the nano silicon carbide particles and nano titanium dioxide in the three-dimensional network structure, resulting in uneven distribution of the nanoparticles in the system and a decrease in the performance of the housing. In Comparative Example 4, when preparing the modified polyether ether ketone pellets, the amount of 60 parts of polyether ether ketone resin was increased to 86 parts and no nano silicon carbide particles and nano titanium dioxide were added. The lack of these nanoparticle reinforcing phases makes the rigidity and strength of the housing both poor. At the same time, without nano silicon carbide particles and nano titanium dioxide, an efficient heat conduction network cannot be formed with carbon fiber, resulting in a decrease in the fatigue resistance of the housing. In Comparative Example 5, since no spiral water channel was provided in the double-layer hollow housing, the accumulation of thermal stress in the housing cannot be effectively relieved, and the heat cannot be quickly exported to achieve rapid cooling of the housing, resulting in a greatly increased risk of cracking and deformation of the housing.

[0041] In summary, through the simultaneous improvement of the material formula and structural design, the mechanical properties of the housing are greatly improved, the heat exchange efficiency of the housing is increased, the heat conduction performance of the housing is improved, the durability and stability of the housing are enhanced, the service life of the mold is extended, and the housing not only meets the usage requirements of the rock specimen mold under complex working conditions, but also provides more possibilities for users to conduct research and production.

[0042] The above are only the embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A housing, characterized in that: Obtained according to the following preparation steps: 81-89 parts of modified polyetheretherketone pellets, 10-16 parts of carbon fibers and 1-3 parts of antioxidant Irganox1010 are uniformly mixed and then injection molded into a shell embryo, and a polytetrafluoroethylene layer is sprayed on the inner wall of the shell embryo to obtain a finished product; The modified polyetheretherketone granular preparation method comprises the following steps: 53-67 parts of polyetheretherketone resin, 12-16 parts of nano silicon carbide particles, 10-14 parts of nano titanium dioxide, 5-9 parts of diphenylmethane diisocyanate and 6-8 parts of triphenylphosphine are uniformly mixed, put into a twin-screw extruder for melt blending and then extruded to obtain modified polyetheretherketone particles.

2. The housing according to claim 1, characterized in that: During the injection molding process of the double-layer hollow shell, the temperatures of the various zones of the injection molding machine are: the temperature of zone one is 370-380°C, the temperature of zone two is 380-390°C, the temperature of zone three is 390-400°C, the injection pressure is 100-120 MPa, the holding pressure is 60-80 MPa, and the holding time is 10-15 seconds.

3. The housing according to claim 1, characterized in that: The screw speed of the twin-screw extruder is 250-350 r / min, and the temperature of each zone of the twin-screw extruder is: the temperature of zone 1 is 360-370°C, the temperature of zone 2 is 370-380°C, the temperature of zone 3 is 380-390°C, the temperature of zone 4 is 390-400°C, and the head temperature is 400-410°C.

4. The housing according to claim 1, characterized in that: Before spraying the polytetrafluoroethylene layer, the inner wall of the double-layer hollow shell is lightly polished to remove burrs, and then cleaned with ethanol to remove oil stains. After spraying, the double-layer hollow shell is placed in a curing furnace, heated to 370-380°C at a heating rate of 3-7°C / min, and kept at this temperature for 1-2 hours, and then cooled to room temperature with the furnace to fully cure the polytetrafluoroethylene coating.

5. The housing according to claim 1, characterized in that: The thickness of the polytetrafluoroethylene layer is 0.1 to 0.2 mm.

6. The housing according to claim 1, characterized in that: The shell is a double-layer hollow structure with a spiral water channel therein. The shell has a penetrating inner shell space. The double-layer hollow shell is also provided with an integrally formed first through hole, and the first through hole is connected to the inner shell space.

7. A rock specimen mold, characterized in that: It comprises a base (1) and a shell (2) as claimed in claim 6; the shell (2) is arranged on the base (1) and is magnetically connected to the base (1); a circulating coolant passes through the spiral water channel of the shell (2), the circulating coolant is water or ethylene glycol, and the circulating coolant is connected by an external circulating pump; the through-plate member (3) passes through the first through hole (21), the space inside the shell and the first through hole (21) on the other side in sequence.

8. The rock specimen mold according to claim 7, characterized in that: An electromagnet is mounted on the base (1), the electromagnet is connected to a power source, a permanent magnet is mounted on the bottom of the shell (2), the polarity of the electromagnet is opposite to the polarity of the permanent magnet, when the electromagnet is powered on, the magnetic field generated by the electromagnet interacts with the magnetic field of the permanent magnet, thereby achieving a magnetic connection between the base (1) and the shell (2), and when the electromagnet is powered off, the magnetic field disappears and the magnetic connection is released.

9. The rock specimen mold according to claim 7, characterized in that: A micro vibrator (12) is provided at the bottom of the base (1).

10. The rock specimen mold according to claim 7, characterized in that: A detachable baffle is attached to the inner wall of the shell (2), and a second through hole is provided on the baffle. The surface of the baffle is provided with a texture. The position of the second through hole corresponds to the position of the first through hole (21), and the two have different shapes. By adjusting the position of the baffle, the first through hole (21) and the second through hole are partially overlapped to form through holes of different shapes. The through-plate member (3) passes through the first through hole (21), the second through hole, the space inside the shell, and the first through hole (21) and the second through hole on the other side in sequence. The cross-sectional area of ​​the through-plate member (3) is consistent with the shape of the through hole.

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