Microwave atmosphere furnace for simulating meteorite impact fusion pulse and cold contraction crack

Abstract

The utility model provides a microwave atmosphere furnace for simulating meteorite impact fusion pulse and cold contraction crack, and belongs to the technical field of planet impact meteology. The atmosphere furnace comprises a reaction furnace, a pulse modulation assembly and an air pump assembly. The reaction furnace is provided with a reaction cavity, and a meteorite sample is arranged in the reaction cavity. The pulse modulation assembly is connected with the reaction furnace, and the pulse modulation assembly is configured to output pulse microwaves to the interior of the reaction cavity so as to heat the aerolite sample to a molten state. The gas pump assembly is communicated with the reaction cavity, the gas pump assembly comprises a vacuum pump and a gas pump, the vacuum pump is configured to suck the reaction cavity to a vacuum state so that the aerolite sample can be heated to a molten state in the vacuum state, and the gas pump is configured to spray inert gas into the reaction cavity so as to cool the aerolite sample in the molten state. The atmosphere furnace disclosed by the utility model is beneficial to more accurately simulating the fusion evolution process after aerolite impact.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of planetary impact meteorite, especially relates to a microwave atmosphere furnace for simulating meteorite impact melting vein and cold shrinkage crack. BACKGROUND

[0002] Meteorite impact is a key dynamic process in the evolution of planets. High-speed celestial bodies release a huge amount of kinetic energy in an instant, causing the target rock to heat up to a molten state within a few seconds, and then rapidly cool down in milliseconds to seconds, forming glassy melt veins and accompanying dense cold shrinkage cracks. This process is widespread in super-speed collisions between asteroid parent bodies in the solar system, and is one of the core bases for studying planetary accretion and meteorite formation history. Impact melt veins are usually composed of two parts: one is the glassy matrix formed by rapid cooling, containing nanometer to micrometer-sized silicate mineral crystals, glass phase, iron-nickel alloy and metal sulfide; the other is the host rock inclusion, mainly composed of olivine, pyroxene, plagioclase and their high-pressure or decomposed variants, also known as multi-phase host rock spherule inclusions. In recent years, nearly 20,000 meteorites have been collected during the Chinese Antarctic expedition, more than one-fifth of which contain impact melt veins, indicating that this structure is widely distributed in the samples and has significant research value.

[0003] However, there are still three major technical bottlenecks in reproducing the above transient melting-cooling structure in the laboratory: one is the lack of uniformity in heating, two is the difficulty in controlling the cooling rate, and three is the poor repeatability of the process. Existing methods such as laser heating, explosive impact or air gun device have high instantaneous energy density, but have problems such as non-uniform heat field distribution and difficulty in controlling the cold end, making it difficult to systematically obtain the true glass vein structure and crack evolution characteristics. UTILITY MODEL CONTENT

[0004] The utility model provides a kind of microwave atmosphere furnace for simulating meteorite impact melting vein and cold shrinkage crack, its purpose is to improve the uniformity of heating to meteorite sample, and improve the cooling rate of meteorite sample in molten state, help to simulate the melting evolution and cold shrinkage process after meteorite impact more accurately.

[0005] In order to achieve the above purpose, the utility model provides a kind of microwave atmosphere furnace for simulating meteorite impact melting vein and cold shrinkage crack, comprising:

[0006] Reaction furnace has reaction cavity, and the reaction cavity is provided with meteorite sample;

[0007] Pulse modulation component is connected with the reaction furnace, and the pulse modulation component is configured to output pulse microwave inside the reaction cavity to heat the meteorite sample to a molten state;

[0008] A gas pump assembly is in communication with the reaction chamber, the gas pump assembly includes a vacuum pump and a gas pump, the vacuum pump is configured to pump the reaction chamber to a vacuum state, so that the meteorite sample can be heated to the molten state under the vacuum state, the gas pump is configured to spray inert gas inside the reaction chamber to cool the meteorite sample in the molten state.

[0009] In an embodiment, the atmosphere furnace includes an alarm assembly, the alarm assembly includes a power sensor, a temperature sensor, a flow rate sensor and an alarm, the power sensor, the temperature sensor and the flow rate sensor are all electrically connected with the alarm, the power sensor is configured to monitor the power of the pulse modulation assembly, the temperature sensor is configured to monitor the temperature inside the reaction chamber, the flow rate sensor is configured to monitor the flow rate of the inert gas sprayed by the gas pump, when the power of the pulse modulation assembly is greater than a first preset value, and / or, the temperature inside the reaction chamber is greater than a second preset value, and / or, the flow rate of the inert gas sprayed by the gas pump is greater than a third preset value, the alarm can issue an alarm.

[0010] In an embodiment, the atmosphere furnace includes a liner, the liner is arranged in the reaction chamber, and the liner covers the surface of the meteorite sample.

[0011] In an embodiment, the material of the liner is configured as a low dielectric constant aluminum oxide material.

[0012] In an embodiment, the pulse modulation assembly includes a pulse width modulation controller and a microwave source, the microwave source is configured to output pulsed microwaves inside the reaction chamber, and the pulse width modulation controller is configured to control the average output power of the microwave source by adjusting the pulse duty cycle.

[0013] In an embodiment, the atmosphere furnace includes a cooling assembly, the cooling assembly includes a water pump and a liquid cooling pipeline, the water pump is connected with the liquid cooling pipeline, so that the cooling liquid in the liquid cooling pipeline can flow in the liquid cooling pipeline, and part of the structure of the liquid cooling pipeline surrounds the outer periphery of the microwave source to cool the microwave source.

[0014] In an embodiment, the reaction furnace includes a furnace body and a quartz window, the furnace body is provided with an observation window, the quartz window is arranged on the observation window to surround the reaction chamber with the furnace body and the quartz window, the quartz window is transparent, and the reaction furnace further includes a metal microwave shielding net, the metal microwave shielding net is arranged on the side of the quartz window away from the reaction chamber, and the mesh size of the metal microwave shielding net is less than 1 / 10 of the wavelength of the pulsed microwaves to prevent microwave leakage.

[0015] The above scheme of the utility model has the following beneficial effects:

[0016] In the embodiment of the application, the integrated atmosphere furnace of pulse microwave volume heating and inert gas flow high-speed cooling is constructed. The temperature is raised in seconds to minutes through pulse power modulation, and the controlled quenching rate of more than or equal to 50 DEG C / s provided by the argon or nitrogen jet is matched to cool the inside of the reaction cavity 1a and the meteorite sample 200, so that the formation of the glassy melt vein with dense cold shrinkage cracks is simulated more accurately. The glassy melt vein and cold shrinkage crack network with a thickness of 0.1-1mm can be obtained on the meteorite sample, and the three problems of heating uniformity, cooling rate and repeatability are solved, and a new efficient and controllable device for simulating the melt evolution process after meteorite impact is provided.

[0017] Other beneficial effects of the utility model will be described in detail in the following specific embodiment part. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a structure schematic view of the atmosphere furnace in an embodiment of the utility model;

[0019] Figure 2 It is a sectional structure schematic view of the atmosphere furnace in an embodiment of the utility model;

[0020] Figure 3 It is a curve of microwave power, meteorite sample temperature and inert gas flow rate changing with time in an embodiment of the utility model.

[0021] EXPLANATION OF REFERENCE NUMERALS

[0022] 100, atmosphere furnace; 1, reaction furnace; 1a, reaction cavity; 11, furnace body; 11a, observation window; 12, quartz window; 2, pulse modulation assembly; 3, gas pump assembly; 31, vacuum pump; 32, gas pump; 41, temperature sensor; 42, flow rate sensor; 43, alarm; 5, bushing; 6, cooling assembly; 200, meteorite sample. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical schemes and advantages to be solved by the utility model more clear, the following will be described in detail in combination with the drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model. In addition, the technical features involved in different implementation manners of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0024] In the description of the utility model, it needs to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the device or element must have a specific orientation, a specific orientation and operation, therefore, cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" and "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0025] In the description of the utility model, it needs to explain, the term "center", "upper", "lower", "left", "right", "vertical", "horizontal", "internal", "external" and so on indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawing, only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the device or element must have a specific orientation, a specific orientation and operation, therefore, cannot be understood as a limitation on the utility model. In addition, the terms "first", "second" and "third" are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0026] The application aims to provide an improved microwave atmosphere furnace with compact structure and adjustable parameters, which can realize efficient and uniform pulse microwave heating and rapid inert gas flow cooling of centimeter-level meteorite samples under laboratory conditions, so as to controllably reproduce the molten vein formed after meteorite impact and the associated cold shrinkage crack structure, thereby solving the technical bottlenecks of existing methods in heating uniformity, cooling rate control and experimental repeatability.

[0027] Specifically, referring to Figure 1 and Figure 2 , the microwave atmosphere furnace 100 for simulating meteorite impact molten vein and cold shrinkage crack of the application comprises a reaction furnace 1, a pulse modulation assembly 2 and a gas pump assembly 3.

[0028] The reaction furnace 1 has a reaction cavity 1a, and a meteorite sample 200 is arranged in the reaction cavity 1a, so that the meteorite sample 200 can be tested in a more controllable space.

[0029] The pulse modulation assembly 2 is connected with the reaction furnace 1, and the pulse modulation assembly 2 is configured to output pulse microwaves inside the reaction cavity 1a to heat the meteorite sample 200 to a molten state. For example, the size of the meteorite sample 200 is configured to be centimeter-level, and the power peak of the pulse microwaves output by the pulse modulation assembly 2 to the meteorite sample can reach 6kW, so that the pulse modulation assembly 2 can more quickly and uniformly heat the meteorite sample 200 to a molten state, which is used to simulate the huge energy released by a high-speed celestial body in the impact moment to melt the meteorite.

[0030] The gas pump assembly 3 is in communication with the reaction chamber 1a. The gas pump assembly 3 comprises a vacuum pump 31 and a gas pump 32. The vacuum pump 31 is configured to pump the reaction chamber 1a to a vacuum state for simulating the vacuum environment of a meteorite in space, so that the meteorite sample 200 can be heated to a molten state in the vacuum state. The gas pump 32 is configured to inject inert gas into the reaction chamber 1a to cool the meteorite sample 200 in the molten state. For example, the inert gas can be argon or nitrogen. The argon or nitrogen is injected into the reaction chamber 1a at a flow rate of 10 m / s to 60 m / s under the action of the gas pump 32 to cool the meteorite sample 200. It can be understood that the inert gas is relatively stable in chemical properties and is not easy to chemically react with the meteorite sample 200 in the molten state, so as to simulate the process of cooling the meteorite in the molten state in the vacuum environment of space.

[0031] Exemplarily, referring to Figure 1 The vacuum pump 31 can share the same pipeline with the gas pump 32 to communicate with the reaction furnace 1, so as to reduce the opening on the reaction furnace 1. The pipeline can be connected with the reaction furnace 1 through a high-speed electromagnetic valve and a quick-release flange. When the vacuum pump 31 pumps the air in the reaction chamber 1a, and the gas pump 32 injects the inert gas into the reaction chamber 1a, the high-speed electromagnetic valve can be opened to connect the gas pump assembly 3 and the reaction furnace 1; when the pulse modulation assembly 2 heats the meteorite sample 200 by microwaves, the high-speed electromagnetic valve can be closed to keep the reaction furnace 1 in a vacuum state.

[0032] Exemplarily, referring to Figure 3 When the test starts, the meteorite sample 200 is placed in the reaction furnace 1, and the reaction furnace 1 is pumped to a vacuum state by the vacuum pump 31. Within 1 to 300 seconds, the pulse modulation assembly 2 continuously emits pulsed microwaves to heat the meteorite sample 200, and the temperature of the meteorite sample 200 is continuously increased. When the meteorite sample 200 is in a molten state, the molten state of the meteorite sample 200 is maintained for 1 to 5 seconds. Then the pulse modulation assembly 2 is stopped, and the gas pump 32 is started within 0 to 0.2 seconds to inject inert gas into the reaction chamber 1a at a primary cooling rate of 50°C / s. When the meteorite sample 200 returns to room temperature, it is taken out of the reaction furnace 1 and subjected to microscopic or non-destructive characterization.

[0033] In the embodiments of the present application, an integrated atmosphere furnace 100 of pulsed microwave volume heating and inert gas high-speed cooling is constructed. Through the realization of second-level to minute-level temperature rise by pulse power modulation, and the provision of a controlled quenching rate of greater than or equal to 50 ℃ / s by argon or nitrogen jet, the inside of the reaction cavity 1a and the meteorite sample 200 are cooled to more accurately simulate the formation of glassy melt veins accompanied by dense cold shrinkage cracks. A glassy melt vein and a cold shrinkage crack network with a thickness of 0.1-1 mm can be obtained on the meteorite sample 200, solving the three major problems of heating uniformity, cooling rate and repeatability, and providing an efficient and controllable new device for simulating the melting evolution process after meteorite impact.

[0034] In an embodiment, referring to Figure 1 and Figure 2 , the atmosphere furnace 100 includes an alarm assembly, which includes a power sensor (not shown in the figure), a temperature sensor 41, a flow rate sensor 42, and an alarm 43. The power sensor, the temperature sensor 41, and the flow rate sensor 42 are all electrically connected to the alarm 43. The power sensor is configured to monitor the power of the pulse modulation assembly 2. The temperature sensor 41 is configured to monitor the temperature inside the reaction cavity 1a. For example, the temperature sensor 41 can be an infrared temperature gun and / or an infrared temperature meter. Compared with a metal thermocouple, the infrared temperature gun and the infrared temperature meter can reduce the possibility of microwave induction heating and discharge. The flow rate sensor 42 is configured to monitor the flow rate of the inert gas sprayed by the gas pump 32. For example, the flow rate sensor 42 can be a barometer and / or a flowmeter. When the power of the pulse modulation assembly 2 is greater than a first preset value, and / or, the temperature inside the reaction cavity 1a is greater than a second preset value, and / or, the flow rate of the inert gas sprayed by the gas pump 32 is greater than a third preset value, the alarm 43 can issue an alarm, thereby reminding the test personnel to terminate the test, so as to reduce the possibility of damage to the atmosphere furnace 100.

[0035] In an embodiment, referring to Figure 2 , the atmosphere furnace 100 includes a bushing 5 arranged in the reaction cavity 1a, and the bushing 5 covers the surface of the meteorite sample 200, so as to reduce the heat dissipation rate of the surface of the meteorite sample 200, and facilitate the speed of the meteorite sample 200 entering the molten state.

[0036] In an embodiment, the material of the bushing 5 is configured as a low-dielectric-constant alumina material, so that the melting point of the bushing 5 is relatively high, and then the properties of the bushing 5 can still remain relatively stable when the meteorite sample 200 is in a molten state.

[0037] In an embodiment, the pulse modulation assembly 2 comprises a pulse width modulation controller and a microwave source, the microwave source is configured to output pulsed microwaves inside the reaction cavity 1a. The pulse width modulation controller is configured to control the average output power of the microwave source by adjusting the pulse duty cycle. For example, the pulse width modulation controller can pulse modulate the output power of the microwave source in the range of 1s~10s to quickly adjust the output power of the microwave source. It should be noted that the duty cycle refers to the ratio of the on time to the total time in one pulse cycle. The duty cycle of the pulsed microwaves of the microwave source can be 5%~100%.

[0038] In an embodiment, referring to Figure 1 , the atmosphere furnace 100 comprises a cooling assembly 6. The cooling assembly 6 comprises a water pump and a liquid cooling pipeline, the water pump is connected with the liquid cooling pipeline to enable the cooling liquid in the liquid cooling pipeline to flow in the liquid cooling pipeline. Part of the structure of the liquid cooling pipeline surrounds the outer peripheral side of the microwave source to keep the microwave source within the safe working temperature range, which reduces the possibility of damage of the microwave source due to overheating, is conducive to improving the service life of the atmosphere furnace 100, and is also conducive to improving the repeatability of the simulation of the molten evolution process after meteorite impact.

[0039] In an embodiment, referring to Figure 1 and Figure 2 , the reaction furnace 1 comprises a furnace body 11 and a quartz window 12, the furnace body 11 is provided with an observation window 11a, and the quartz window 12 is arranged on the observation window 11a to surround the reaction cavity 1a with the furnace body 11 and the quartz window 12. The quartz window 12 is transparent to facilitate the tester to observe the state of the meteorite sample 200 in the reaction cavity 1a through the quartz window 12. The reaction furnace 1 further comprises a metal microwave shielding net (not shown in the figure), which is arranged on the side of the quartz window 12 away from the reaction cavity 1a. The mesh size of the metal microwave shielding net is less than 1 / 10 of the wavelength of the pulsed microwaves to prevent microwave leakage.

[0040] The above is the preferred embodiment of the present application. It should be noted that for ordinary skilled persons in the technical field, without departing from the principle of the present application, a number of improvements and refinements can be made, which should also be considered as the protection scope of the present application.

Claims

1. A microwave atmosphere furnace for simulating meteorite impact melt veins with cold shrinkage cracks, characterized by, The atmosphere furnace comprises a reaction furnace having a reaction cavity in which a meteorite sample is arranged; a pulse modulation assembly connected with the reaction furnace, the pulse modulation assembly being configured to output pulsed microwaves inside the reaction cavity to heat the meteorite sample to a molten state; a gas pump assembly in communication with the reaction cavity, the gas pump assembly comprising a vacuum pump and a gas pump, the vacuum pump being configured to pump the reaction cavity to a vacuum state so that the meteorite sample can be heated to the molten state under the vacuum state, and the gas pump being configured to spray inert gas inside the reaction cavity to cool the meteorite sample in the molten state. The atmosphere furnace comprises an alarm assembly comprising a power sensor, a temperature sensor, a flow rate sensor and an alarm, the power sensor, the temperature sensor and the flow rate sensor being electrically connected with the alarm, the power sensor being configured to monitor the power of the pulse modulation assembly, the temperature sensor being configured to monitor the temperature inside the reaction cavity, and the flow rate sensor being configured to monitor the flow rate of the inert gas sprayed by the gas pump, the alarm being capable of sounding an alarm when the power of the pulse modulation assembly is greater than a first preset value, and / or the temperature inside the reaction cavity is greater than a second preset value, and / or the flow rate of the inert gas sprayed by the gas pump is greater than a third preset value. The atmosphere furnace comprises a bushing arranged in the reaction cavity, the bushing being wrapped around the surface of the meteorite sample. The material of the bushing is configured to be a low-dielectric-constant alumina material.

2. The microwave atmosphere furnace for simulating the meteorite impact melt vein with cold shrinkage crack according to claim 1, characterized in that, The pulse modulation assembly comprises a pulse width modulation controller and a microwave source, the microwave source being configured to output pulsed microwaves inside the reaction cavity, and the pulse width modulation controller being configured to control the average output power of the microwave source by adjusting the pulse duty cycle.

3. The microwave atmosphere furnace for simulating the meteorite impact melt vein with cold shrinkage cracks according to claim 1, characterized in that, The atmosphere furnace comprises a cooling assembly comprising a water pump and a liquid cooling pipeline, the water pump being connected with the liquid cooling pipeline to enable cooling liquid in the liquid cooling pipeline to flow in the liquid cooling pipeline, and part of the structure of the liquid cooling pipeline being wrapped around the outer periphery of the microwave source to cool the microwave source.

4. The microwave atmosphere furnace for simulating a melt vein from a meteorite impact with a cold shrink crack of claim 3, wherein, The reaction furnace comprises a furnace body having an observation window and a quartz window covering the observation window to enclose the reaction cavity with the furnace body and the quartz window, the quartz window being transparent, and the reaction furnace further comprising a metal microwave shielding net arranged on the side of the quartz window away from the reaction cavity, the mesh size of the metal microwave shielding net being less than 1 / 10 of the wavelength of the pulsed microwaves to prevent microwave leakage.

5. The microwave atmosphere furnace for simulating the meteorite impact melt vein with cold shrinkage cracks according to claim 1, characterized in that, ​ 6. The microwave atmosphere furnace for simulating a melt vein from a meteorite impact with a cold shrink crack of claim 5, wherein, ​ 7. The microwave atmosphere furnace for simulating a melt vein from a meteorite impact with a cold shrink crack of claim 1, wherein, ​

Images