CN-224215847-U - Multi-size detachable combined graphite die suitable for plasma sintering

CN224215847UCN 224215847 UCN224215847 UCN 224215847UCN-224215847-U

Abstract

The utility model provides a many sizes detachable combination graphite mould suitable for plasma sintering, belong to plasma sintering graphite mould design manufacturing field, in order to solve the combination that can adjust the mould according to the size of required sample, and then reach the problem of required size requirement, the technical essential is that middle die sleeve includes a plurality of different diameters's middle die sleeve, middle die sleeve is cylindric, the bellied upper surface of lower base supports the bottom of middle die sleeve, the coaxial nestification of middle die sleeve of different diameters, arrange on the upper surface of base, the pressure head of different diameters can cooperate with the middle die sleeve of different diameters, outer die sleeve is cylindric, the coaxial nestification of outer die sleeve is arranged in the outside of protruding and supporting the middle die sleeve at protruding upper surface, the upper surface of lower base supports the bottom of the section of thick bamboo of outer die sleeve, the effect is that graphite mould can be dismantled, each part can be singly changed, and according to the size of sample can adjust the combination of mould at any time, and then reach required size requirement.

Inventors

LI MU
LIU MINGSHANG
TANG DAWEI

Assignees

大连理工大学

Dates

Publication Date: 20260508
Application Date: 20250516

Claims (10)

1. A multi-size detachable combined graphite die suitable for plasma sintering is characterized by comprising A first electrode; The upper surface of the upper base is provided with a first electrode, the lower part of the upper base is provided with a plurality of cylindrical grooves with different diameters, and the cylindrical grooves with different diameters are concentric stepped cylindrical grooves with gradually increased diameters; the pressure head comprises a plurality of pressure heads with different diameters, the pressure heads are cylindrical, and the pressure heads with different diameters can be matched with the cylindrical grooves with different diameters; a second electrode; the lower surface of the lower base is provided with a second electrode, and the center of the upper surface of the lower base is formed with a bulge higher than the upper surface; The middle die sleeve comprises a plurality of middle die sleeves with different diameters, the middle die sleeves are cylindrical, the upper surface of the bulge of the lower base is supported at the bottom of the middle die sleeve, the middle die sleeves with different diameters are coaxially nested and arranged on the upper surface of the base, and the pressure heads with different diameters can be matched with the middle die sleeves with different diameters; The outer die sleeve is cylindrical, is coaxially nested and arranged outside the middle die sleeve which is raised and supported on the upper surface of the raised, and the upper surface of the lower base is supported on the bottom of the cylinder of the outer die sleeve; The gaskets are in a disc shape, the gaskets with different diameters can be matched with the middle die sleeves with different diameters, the gaskets are arranged at the bottom of the middle die sleeves, and the bottom surface of the gasket is supported by the upper surface of the bulge of the lower base; Wherein, go up base, pressure head, lower base, middle die sleeve, external mold cover and gasket are graphite material.
2. The multi-sized removable graphite mold for plasma sintering of claim 1, wherein the protrusions have a first height in an axial direction, the middle mold sleeve has a second height in an axial direction, the outer mold sleeve has a third height in an axial direction, and a sum of the first height and the second height is less than the third height.
3. The multi-sized detachable combined graphite mold suitable for plasma sintering according to claim 1, wherein any two adjacent intermediate mold sleeves among the intermediate mold sleeves with different diameters are abutted against each other, and the inner wall of the outer intermediate mold sleeve is abutted against the outer wall of the inner intermediate mold sleeve, and the outer wall of the outer intermediate mold sleeve is abutted against the inner wall of the outer mold sleeve.
4. The multi-sized detachable combined graphite mold suitable for plasma sintering according to claim 1, wherein the upper base comprises a substrate and a protrusion arranged below the substrate, and the protrusion forms a plurality of cylindrical grooves with different diameters.
5. The multi-sized removable graphite mold for plasma sintering of claim 1, wherein the lower base comprises a base and a protrusion disposed above the base.
6. The multi-size removable graphite mold for plasma sintering of claim 1, wherein the fit between the ram and the cylindrical recess is a clearance fit and the fit between the ram and the intermediate sleeve is a clearance fit.
7. The multi-sized detachable combined graphite mold suitable for plasma sintering according to claim 1, wherein, The pressure head comprises a first pressure head, a second pressure head and a third pressure head; The concentric stepped cylindrical groove comprises a first cylindrical groove, a second cylindrical groove and a third cylindrical groove; the middle die sleeve comprises a first middle die sleeve, a second middle die sleeve and a third middle die sleeve; The opening diameter of the outer die sleeve is matched with the outer diameter of the third middle die sleeve, the opening diameter of the third die sleeve is matched with the outer diameter of the second middle die sleeve, and the opening diameter of the second die sleeve is matched with the outer diameter of the first middle die sleeve; The diameter of the opening of the third die sleeve is matched with the diameter of the third pressure head, the diameter of the opening of the second die sleeve is matched with the diameter of the second pressure head, and the diameter of the opening of the first die sleeve is matched with the diameter of the first pressure head; The diameter of the opening of the third cylindrical groove is matched with the diameter of the third pressure head, the diameter of the opening of the second cylindrical groove is matched with the diameter of the second pressure head, and the diameter of the opening of the first cylindrical groove is matched with the diameter of the first pressure head.
8. The multi-sized removable composite graphite mold suitable for plasma sintering of claim 1, wherein the gasket comprises a first gasket, a second gasket, and a third gasket; the first gasket is adapted to the diameter of the first intermediate die sleeve and can be arranged at the bottom of the first intermediate die sleeve, the second gasket is adapted to the diameter of the second intermediate die sleeve and can be arranged at the bottom of the second intermediate die sleeve, and the third gasket is adapted to the diameter of the third intermediate die sleeve and can be arranged at the bottom of the third intermediate die sleeve.
9. The multi-sized detachable combined graphite mold for plasma sintering according to claim 1, wherein the thickness of the gasket is 10mm.
10. The multi-sized detachable combined graphite mold for plasma sintering according to claim 1, wherein the first electrode covers the upper surface of the upper base, and the second motor covers the lower surface of the lower base.

Description

Multi-size detachable combined graphite die suitable for plasma sintering Technical Field The utility model relates to the field of design and manufacture of plasma sintering graphite molds for powder metallurgy and ceramic production, in particular to a multi-size detachable combined graphite mold suitable for plasma sintering. Background Plasma Sintering (SPS) is an advanced rapid sintering technology developed by japan in the 90 th century, aiming to overcome the limitations of conventional sintering (e.g., hot press sintering, pressureless sintering). The traditional method depends on high temperature and long-time heat preservation, is easy to cause coarsening of material grains and high in energy consumption, and is difficult to prepare high-performance nano materials. SPS directly acts on powder particles through pulse direct current, a plasma discharge effect is generated in a die, and the rapid densification (several minutes to several tens minutes) is realized by combining pressure and Joule heat. The core principle is that the surface of the powder is activated by an electric field to accelerate diffusion and atomic migration, so that a high-density material is obtained at a lower temperature. In the preparation process, the dry powder is filled into a graphite mold, and then pulse direct current is conducted from the uniaxial direction while pressurizing, so that the molding and sintering are completed simultaneously. The plasma sintering time is short (SPS only needs a few minutes in the traditional method), the grain growth can be inhibited, and the method is suitable for preparing nanocrystalline and amorphous materials. The activation of the plasma can reduce the sintering temperature (100-300 ℃ lower than the traditional method), save energy consumption and avoid pyrolysis of the material. The density of the product can reach more than 99%, the mechanical and electrical properties are obviously improved, and the technology is especially suitable for ceramic and metal matrix composite materials. In addition, the plasma sintering technology can sinter traditional difficult-to-process materials (such as high-melting point metal and super-hard ceramic) and realize accurate preparation of gradient materials and multilayer structures. And meanwhile, the temperature, the pressure and the current are independently regulated and controlled, so that the microstructure is convenient to optimize, and the generation of impurity phases is reduced. The plasma sintering technology has the defects that powder is directly filled into a graphite mold, and current is directly pressurized, so that raw materials are easy to adhere to the inner wall of the graphite mold in the sintering process, and the mold can react with certain materials (such as active metal) at high temperature, so that the graphite mold is easy to wear and needs to be replaced frequently. In addition, the sintering process may have a phenomenon that the temperature and pressure are set too high, so that part of the sample is melted, and the pressure head may be blocked in the die sleeve. Disclosure of utility model The utility model aims to provide a multi-size detachable combined graphite die, which can adjust the combination of the die at any time according to the size of a required sample, thereby achieving the required size requirement and being easy to replace. A multi-size detachable combined graphite mold suitable for plasma sintering according to some embodiments of the present utility model comprises A first electrode; The upper surface of the upper base is provided with a first electrode, the lower part of the upper base is provided with a plurality of cylindrical grooves with different diameters, and the cylindrical grooves with different diameters are concentric stepped cylindrical grooves with gradually increased diameters; the pressure head comprises a plurality of pressure heads with different diameters, the pressure heads are cylindrical, and the pressure heads with different diameters can be matched with the cylindrical grooves with different diameters; a second electrode; the lower surface of the lower base is provided with a second electrode, and the center of the upper surface of the lower base is formed with a bulge higher than the upper surface; The middle die sleeve comprises a plurality of middle die sleeves with different diameters, the middle die sleeves are cylindrical, the upper surface of the bulge of the lower base is supported at the bottom of the middle die sleeve, the middle die sleeves with different diameters are coaxially nested and arranged on the upper surface of the base, and the pressure heads with different diameters can be matched with the middle die sleeves with different diameters; The outer die sleeve is cylindrical, is coaxially nested and arranged outside the middle die sleeve which is raised and supported on the upper surface of the raised, and the upper surface of the lower base is supported