[0031] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.
[0032] See Figure 1~3 , The embodiment of the present invention provides an ultra-high vacuum electromagnetic suspension material preparation system, which specifically includes: a cavity, a vacuum acquisition unit and a control system; facilities related to the cavity include: a sample suspension mechanism, a sample transmission mechanism, and image acquisition Unit, sample temperature monitoring mechanism, sample position detection mechanism, pressure casting unit and safety and accessory facilities.
[0033] Among them, the cavity is a double-cylindrical structure with a small top and a large bottom. The upper cavity is used for electromagnetic suspension experiments, and the lower cavity is used for pressure casting experiments. The cavity is connected up and down, the liquid metal suspended in the upper cavity can freely fall to the lower cavity without obstacles, and the pressure casting system in the cavity can process the falling melt.
[0034] Preferably, there is a metal partition with a plurality of circular holes at the connection part of the upper cavity and the lower cavity. The partition is used to prevent the high-temperature melt from accidentally falling onto the substrate of the lower cavity. A number of screw holes are distributed on the top for mounting brackets.
[0035] Further, a plurality of screw holes are reserved at the top and bottom of the inner wall of the cavity for installing accessory brackets. Several windows of different sizes are set on the top, side and bottom of the main cavity for observation, manipulation, temperature measurement, image acquisition, signal transmission, vacuum acquisition, thrust transmission, high-frequency current introduction, air flow transmission and cooling water circulation.
[0036] In the embodiment of the present invention, the upper cavity has a diameter of 200-800 mm and a height of 200-800 mm, and the lower cavity has a diameter of 300-900 mm and a height of 300-900 mm.
[0037] Among them, the sample suspension mechanism includes an electromagnetic suspension coil arranged in the cavity and a high-frequency induction heating power supply outside the cavity. Its function is to achieve long-term stable suspension, heating and melting of metals and alloys.
[0038] Among them, the sample transmission mechanism, including a sample transmission rod and a sample storage unit, is used to sequentially implement multiple sample suspension experiments and recovery tasks under the premise of one vacuum extraction. The sample transfer mechanism is powered by a stepping motor, and manipulates the mechanical arm inside the cavity to move with 2 degrees of freedom. One is vertical movement up and down, and the other is horizontal rotation movement.
[0039] Among them, the image acquisition unit adopts a camera to realize real-time collection of information such as sample contour, sample position, and sample movement status. The image acquisition unit and the suspended sample are located at the same level.
[0040] Among them, the sample temperature monitoring mechanism includes an infrared thermometer and a set of gas pipelines connected to the external gas source of the cavity. The non-contact temperature measurement of the material in the electromagnetic suspension process is realized by an infrared thermometer, and the temperature of the metal body is controlled by adjusting the airflow speed, the direction of the blowing port and the diameter of the pipe.
[0041] Among them, the sample position detection mechanism uses a high-speed camera, laser or photodiode to detect the sample position.
[0042] Among them, the die casting unit includes pneumatic, hydraulic or electromagnetic means to provide power to advance the mold, combined with photoelectric detection technology to obtain accurate falling position and time, and the computer adjusts the mold advancing speed and direction according to the above information, so that the falling droplets solidify and form. The mold is made of metal or alloy, and several slender cavities are distributed on the mold. Thermocouples can be installed to obtain the heat transfer information of the metal solidification environment.
[0043] Among them, safety and accessory facilities include lighting electrodes, vacuum chamber safety valves and vacuum gauges.
[0044] The image acquisition unit, the sample temperature monitoring mechanism, the sample position detection mechanism, and the die casting unit are all connected to the control system, and the real-time feedback information of the above units is used to adjust the temperature of the sample and the die advance speed of the die casting unit.
[0045] Further explanation: There are several windows on the cavity for sample detection by the above-mentioned various mechanisms. The sample suspension mechanism is located at the central axis of the upper cavity. The sample transfer mechanism is connected to the inside of the vacuum through the top window 10B, and plays a role of transferring samples. The horizontal plane of the window 11, the image acquisition unit and the coil are consistent. The image acquisition unit collects the image of the sample through the transparent window 11; the infrared thermometer is located at the central axis of the top of the cavity, and the temperature information of the sample is acquired through the top transparent window 10A. The sample position detection mechanism is composed of a first position detector, a second position detector, and a control system. The first position detector and the second position detector are distributed at different heights of the upper cavity and are used to detect the falling of the melt. time. The sample temperature monitoring mechanism is composed of gas source, gas path equipment, infrared thermometer, etc., according to the target temperature and real-time sample temperature, temperature control is realized by computer or manually. The die casting unit includes a mold, connecting parts, a driving device and a thermocouple. The mold is located inside the lower cavity and is connected to the inside and the outside through a bellows.
[0046] Correct figure 2 with image 3 Explain: In the figure, 1 is the sample, 2 is the electromagnetic coil, 3A is the upper cavity, 3B is the lower cavity, 4 is the sample transmission system, 5 is the infrared thermometer, 6A is the first position detector, and 6B is the first position detector. Two-position detector, 7A is the right mold drive unit, 8A is the right mold drive unit, 7B is the left mold drive unit, 8B is the left mold, 9 is the slide rail, 10A is the top center window, 10B is the top spare window, 11 is the side window, 12 is the control system, 13A is the front observation window of the upper cavity, 13B is the front observation window of the lower cavity, 14 is the vacuum extraction window, 15A and 15B are the connection windows for pressure casting, and 16 is the mold water cooling connection window. 17 is a gas circuit interface, 18 is a power and signal transmission interface, 19 is a thermocouple, 20 is a high-frequency induction power supply, 21 is a high-pressure gas cylinder, and 22 is a metal partition.
[0047] The embodiment of the present invention provides another method for preparing an ultra-high vacuum electromagnetic suspension material. Taking the preparation of large-volume metal Ni as an example, the method specifically includes:
[0048] 1. Electromagnetic suspension deep subcooling and basic thermophysical properties experiment of bulk metal.
[0049] Step 1: Preparation of the suspension environment and electromagnetic suspension of large-volume metal.
[0050] Through the vacuum acquisition system, the cavity can reach the target vacuum degree. Close the vacuum acquisition system and fill with inert gas. The coil excitation current is adjusted by the high-frequency induction heating power supply to make the sample float stably.
[0051] Step 2: Maintain the target temperature.
[0052] Continuous suspension heating, real-time control of the temperature change of the sample through the sample temperature acquisition system. When the sample temperature reaches above the liquidus line, under the control of the control system, continuous heating is combined with the sample temperature monitoring mechanism to maintain the sample temperature near the target temperature.
[0053] Step 3: Collection of basic thermophysical properties.
[0054] The profile, deformation and surface vibration of the sample are analyzed through the image acquisition system, and the thermophysical properties such as the density and surface tension of the sample at a certain temperature are obtained. The temperature is adjusted by the sample temperature monitoring system to obtain a variety of thermophysical properties at different temperatures.
[0055] Step 4. Deep subcooling experiment of bulk metal.
[0056] Through the temperature monitoring system, the air flow speed and blowing direction are adjusted, and the temperature of the liquid sample is reduced to below the liquidus in the suspended state, so that the sample obtains a deep supercooled state. Combined with the image acquisition unit and the temperature detection mechanism, the rapid solidification behavior of the sample can be observed and collected in real time.
[0057] 2. Electromagnetic suspension pressure casting experiment of bulk metal.
[0058] Step 1: Preparation of the suspension environment and electromagnetic suspension of large-volume metal.
[0059] Through the vacuum acquisition system, the cavity can reach the target vacuum degree. Close the vacuum acquisition system, and then fill with inert gas. The coil excitation current is adjusted by the high-frequency induction heating power supply to make the sample float stably.
[0060] Step 2: Maintain the target temperature.
[0061] Continuous suspension heating, real-time control of the temperature change of the sample through the sample temperature monitoring system. When the sample temperature reaches above the liquidus line, under the control of the control system, continuous heating is combined with the sample temperature monitoring mechanism to maintain the sample temperature near the target temperature.
[0062] Step 3: Pressure casting of liquid metal samples.
[0063] Turn off the excitation current and the sample drips. The sample position detection mechanism works and feeds back the falling position and time of the liquid metal in real time, and controls the thrust and speed of the mold in the pressure casting unit through the control system to make the liquid metal die-cast into a mold. At the same time, the thermocouple on the mold obtains the temperature change information of the mold in real time.
[0064] The above disclosure is only a few specific embodiments of the present invention. Those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention, provided that these modifications and changes belong to the right of the present invention. Within the scope of the requirements and equivalent technologies, the present invention also intends to include these modifications and variations.
