KR-20260063277-A - Ultra-high pressure isothermal warm isostatic pressing device

KR20260063277AKR 20260063277 AKR20260063277 AKR 20260063277AKR-20260063277-A

Abstract

The present invention provides an ultra-high pressure isothermal warm isotropic forming apparatus comprising a pressure vessel having openings formed on the left and right sides, a left opening/closing door for selectively opening and closing the left opening of the pressure vessel, a right opening/closing door for selectively opening and closing the right opening of the pressure vessel, and a heat conduction module provided inside the pressure vessel to transfer heat of a pressure medium contained therein from a high place to a low place, wherein a heat conductor with high thermal conductivity is placed in the internal space of the pressure vessel to compensate for the lack of heat transfer of the pressure medium through heat conduction, and the pressure medium is forced to convect by increasing the dielectric constant by ultrasonic waves through ultrasonic waves, thereby improving the thermal uniformity of the pressure medium contained inside the pressure vessel.

Inventors

주경
김정환
최인수

Assignees

(주) 미코하이테크

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (14)

A pressure vessel having openings formed on the left and right sides, respectively; A left opening/closing door for selectively opening and closing the left opening of the above pressure vessel; A right opening/closing door for selectively opening and closing the right opening of the pressure vessel; and An ultra-high pressure isothermal warm isotropic forming apparatus comprising a heat conduction module provided inside the pressure vessel and transferring heat of a pressure medium contained inside from a high place to a low place.
In claim 1, The above heat conduction module is, A cylindrical main heat conductor in which the outer surface of the heat conduction module is in close contact with the inner surface of the pressure vessel, and An ultra-high pressure isothermal warm isotropic forming device comprising a side heat conductor coupled to the left opening of the main heat conductor.
In claim 2, The above heat conduction module is, A diaphragm coupled to the right opening of the main heat conductor, and An ultra-high pressure isothermal warm isotropic forming apparatus further comprising an ultrasonic vibrator provided on the above-mentioned diaphragm to vibrate the diaphragm and propagate ultrasonic waves into a pressure medium.
In claim 2, The above main heat conductor is, An ultra-high pressure isothermal warm isotropic forming apparatus characterized by being made of any one of the following materials: graphite, copper, aluminum, or graphite coated with metal.
In claim 2, The above-mentioned side thermal conductor is, An ultra-high pressure isothermal warm isotropic forming apparatus characterized by being made of any one of the following materials: graphite, copper, aluminum, or graphite coated with metal.
In claim 5, The above-mentioned side thermal conductor is, An ultra-high pressure isothermal warm isotropic forming device coupled to the surface facing the left opening of the above-mentioned left opening/closing door, which moves together when the above-mentioned left opening/closing door closes the left opening of the pressure vessel and is coupled to the left opening of the main heat conductor.
In claim 3, The above diaphragm is, An ultra-high pressure isothermal warm isotropic forming apparatus characterized by being made of any one of the following materials: graphite, copper, aluminum, or graphite coated with metal.
In claim 3, The above diaphragm is, An ultra-high pressure isothermal warm isotropic forming device coupled to the surface facing the right opening of the right opening/closing door, which moves together when the right opening/closing door closes the right opening of the pressure vessel and is coupled to the right opening of the main heat conductor.
In claim 3, The above heat conduction module is, An ultra-high pressure isothermal warm isotropic forming device characterized by propagating ultrasound to a pressure medium contained in the pressure vessel to cause convection of the pressure medium contained in the pressure vessel.
In claim 3, The above heat conduction module is, A booster electrically connected to the above-mentioned ultrasonic vibrator and amplifying the amplitude of the ultrasonic waves according to the temperature or pressure applied to the above-mentioned pressure vessel, and An ultra-high pressure isothermal and warm isotropic forming apparatus further comprising an ultrasonic controller mechanically connected to the above ultrasonic vibrator and adjusting the amplitude of the ultrasonic waves according to the temperature or pressure applied to the pressure vessel.
In claim 1, A plate-shaped base installed on the ground, and An ultra-high pressure isothermal warm isotropic forming apparatus further comprising a frame positioned on the upper side of the above base and forming a through space in which the pressure vessel, left opening/closing door, and right opening/closing door are located in the center.
In claim 11, The above pressure vessel is, An ultra-high pressure isothermal warm isotropic forming device characterized by being selectively transported and selectively positioned in the through space of the frame.
In claim 11, The above-mentioned left opening/closing door is positioned to the left based on the point where the pressure vessel is located within the penetration space of the frame, and An ultra-high pressure isothermal warm isotropic forming device characterized in that the above-mentioned right opening/closing door is positioned to the right based on the point where the pressure vessel is located within the penetration space of the above-mentioned frame.
In any one of claims 4, 5, and 7, The metal material having a metal coating on the above graphite is, Ultra-high pressure isothermal warm isostatic forming device characterized by being either copper or aluminum.

Description

Ultra-high pressure isothermal warm isostatic pressing device The present invention relates to an isostatic molding apparatus for producing a product by placing raw material powder into a molding die, introducing it into a pressure vessel, filling the pressure vessel with a pressure medium, and creating a high-temperature, high-pressure atmosphere. More specifically, the invention relates to an ultra-high pressure isothermal and warm isostatic molding apparatus that ensures there is no temperature variation between locations within the pressure vessel by increasing the heat conduction efficiency of the pressure medium and causing convection of the pressure medium even when the pressure inside the pressure vessel rises to ultra-high pressure. Generally, an isotropic forming device is equipment that manufactures a molded body with a dense structure by loading raw material powder, such as ceramic or metal in powder form, into a mold and then applying pressure to the mold using a high-pressure pressure medium, or by sealing the exterior of a primary molded body produced by primary compression, extrusion, or lamination using ceramic or metal powder through means such as vacuum packaging, and then applying high pressure using a pressure medium. In particular, the warm isotropic forming device is a device capable of applying high pressure to a primary formed body after heating the pressure medium to about 100°C, and recently it has been widely used in the manufacture of multilayer ceramic capacitors. Warm isostatic forming devices primarily utilize a structure in which a jacket is installed on the outside of a pressure vessel and heated heat transfer fluid (pressure medium) is circulated through the outer jacket, or a heater is installed to heat the entire pressure vessel. For prior art, refer to Registered Patent No. 10-2591295 (October 16, 2023). Meanwhile, in conventional high-pressure isostatic forming devices, a jacket is installed on the outside of the pressure vessel to adjust the pressure medium to the required temperature, and a high-temperature heat transfer fluid is circulated to conduct heat through the pressure vessel to the pressure medium inside the pressure vessel, thereby raising the temperature of the pressure medium. However, in this case, heat gradually accumulates on the upper side of the pressure vessel, becoming higher than the lower side, and this temperature difference is conducted to the pressure medium, resulting in a temperature difference between the upper and lower parts of the pressure medium. To address these issues, there is a method in which multiple tube heaters are arranged at equal intervals parallel to the longitudinal direction of the pressure vessel but radially around the longitudinal central axis, and multiple thermocouples are installed radially around the longitudinal central axis to measure the temperatures at the top, bottom, front, back, left, and right of the pressure vessel. By receiving temperature feedback from the thermocouples and controlling the radially installed heaters individually, the temperatures across the pressure vessel are leveled to ensure uniform temperature delivery to the pressure medium; however, this method also suffers from the problem that heat accumulates upward over time because almost no convection occurs in the pressure medium under high pressure, eventually resulting in a temperature difference between the top and bottom of the pressure medium. Therefore, since water and oil, which are pressure media, have low thermal conductivity, there are limitations in rapidly and uniformly transferring heat within the vessel; additionally, temperature non-uniformity occurred due to the thermal buoyancy phenomenon of the pressure media inside the pressure vessel (a phenomenon where a higher temperature fluid rises and a lower temperature fluid sinks). In addition, although water is known to be an incompressible fluid, it has a compressibility of about 10% at ultra-high pressures of several hundred MPa. At ultra-high pressures, the distance between molecules of water decreases, so heat conduction increases somewhat, but the density increases, making heat transfer by convection less efficient. Consequently, there was a problem where the non-uniformity of temperature was exacerbated due to heat transfer relying on heat conduction between water molecules. FIG. 1 is an exemplary diagram showing an ultra-high pressure isothermal warm isotropic forming apparatus according to an embodiment of the present invention. FIG. 2 is a side cross-sectional view showing a side cross-section of an ultra-high pressure isothermal warm isotropic forming apparatus according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing a planar cross-section of an ultra-high pressure isothermal warm isotropic forming apparatus according to an embodiment of the present invention. FIG. 4 is an exemplary diagram showing the operation of a pressure vessel o