Mold for molding chalcogenide glass

Abstract

The application discloses a chalcogenide glass die pressing die and relates to the technical field of optical part forming. The chalcogenide glass die pressing die comprises an upper die core, a lower die core and a die sleeve. The upper die core and the lower die core are closed to form a die cavity for accommodating a chalcogenide glass blank. The die sleeve is sleeved on the outer periphery of the upper die core and the lower die core. The inner wall of the side of the die sleeve facing the die cavity is provided with a stress release groove, and the stress release groove is arranged at a position corresponding to the die closing parting gap between the upper die core and the lower die core. An exhaust passage is arranged on the die sleeve, and the first end of the exhaust passage is communicated with the stress release groove, and the second end of the exhaust passage extends to the outer wall of the die sleeve. The die structure cannot simultaneously meet the stress release and exhaust requirements, resulting in poor microstructure precision of the formed diffractive element and low yield of finished products.

Description

Technical Field

[0001] This application relates to the field of optical component molding technology, and in particular to a chalcogenide glass molding die. Background Technology

[0002] Chalcogenide glasses possess advantages such as an ultra-wide infrared transmittance of 1–14 μm and a low temperature coefficient of refractive index, making them a core material for fabricating long-wave infrared diffraction elements. Chalcogenide glass flat diffraction elements are thin-film components that achieve infrared beam shaping, spot modulation, and chromatic aberration correction through surface diffraction microstructure rings. They are widely used in various infrared detection and imaging equipment, and precision molding is the mainstream process for mass production of chalcogenide glass diffraction elements.

[0003] However, the inventors discovered that the existing mold structure could not simultaneously meet the needs of stress release and venting, resulting in poor microstructure precision of the diffraction element after molding and low yield of finished products.

[0004] Therefore, the above problems urgently need to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a chalcogenide glass molding die to solve the problem that the existing mold structure cannot simultaneously meet the needs of stress release and venting, resulting in poor microstructure accuracy of the diffraction element after molding and low yield of finished products.

[0006] To address the aforementioned technical problems, this application provides the following technical solutions: This application provides a chalcogenide glass molding die, comprising: The upper mold core and the lower mold core are joined together to form a mold cavity, which is used to hold the chalcogenide glass preform. A mold sleeve is fitted around the outer periphery of the upper mold core and the lower mold core. The inner wall of the mold sleeve facing the mold cavity is provided with a stress relief groove, and the position of the stress relief groove corresponds to the mold parting gap between the upper mold core and the lower mold core. The mold sleeve is provided with an exhaust channel. The first end of the exhaust channel is connected to the stress relief groove, and the second end extends to the outer wall of the mold sleeve.

[0007] In some embodiments, the aforementioned chalcogenide glass molding die has a stress relief groove that is annular and circumferentially formed on the inner wall of the die sleeve.

[0008] In some embodiments, the aforementioned chalcogenide glass molding die has a rectangular cross-section along the axial direction of the die sleeve for stress relief grooves.

[0009] In some embodiments, the aforementioned chalcogenide glass molding die has a cylindrical mold sleeve; the venting channel extends radially along the cylindrical mold sleeve.

[0010] In some embodiments, the aforementioned chalcogenide glass molding die has venting channels evenly spaced along the circumferential direction of the annular stress relief groove in the die sleeve.

[0011] In some embodiments, the aforementioned chalcogenide glass molding die has a variable diameter section at the first end of the venting channel, wherein the diameter of the variable diameter section facing the stress relief groove is larger than the diameter of the section away from the stress relief groove.

[0012] In some embodiments, the aforementioned chalcogenide glass molding die has a diffractive microstructure ring on the molding end face of the upper mold core and / or lower mold core facing the mold cavity.

[0013] In some embodiments, the aforementioned chalcogenide glass molding die, wherein both the upper and lower mold cores are made of tungsten carbide-niobium carbide composite cemented carbide, and the surface of the tungsten carbide-niobium carbide composite cemented carbide is provided with a nickel-phosphorus-diamond composite film layer; wherein the coefficients of thermal expansion of the tungsten carbide-niobium carbide composite cemented carbide, the nickel-phosphorus-diamond composite film layer, and the chalcogenide glass preform are arranged in descending order.

[0014] In some embodiments, the aforementioned chalcogenide glass molding die has a first positioning step at the upper end of the upper mold core away from the lower mold core; a second positioning step at the lower end of the lower mold core away from the upper mold core; the first positioning step and the second positioning step limit the positioning space; and the mold sleeve is fitted into the positioning space.

[0015] In some embodiments, the aforementioned chalcogenide glass molding die further includes: an outer steel sleeve, which is sleeved on the outside of the first positioning step, the mold sleeve, and the second positioning step; the outer steel sleeve has an exhaust hole, and there is a preset gap between the inner wall of the outer steel sleeve and the mold sleeve, and the exhaust channel communicates with the exhaust hole through the preset gap.

[0016] By means of the above technical solution, the chalcogenide glass molding die of the present invention has at least the following advantages: This application provides a The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of this application are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0017] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of this application are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein: Figure 1 A schematic diagram of the isometric structure of a chalcogenide glass molding die according to the present invention is shown. Figure 2 The diagram schematically illustrates the isometric structure of the upper and lower mold cores of a chalcogenide glass molding die during the mating process. Figure 3 A schematic cross-sectional view of the mold sleeve of a chalcogenide glass molding die according to the present invention is shown. Figure 4 The diagram schematically illustrates a cross-sectional view of the variable diameter section of the venting channel in a chalcogenide glass molding die of the present invention. Figure 5 The diagram schematically illustrates the isometric structure of a diffractive microstructure ring of a chalcogenide glass molding die according to the present invention. Figure 6 The diagram schematically illustrates a top view of the diffraction microstructure ring of a chalcogenide glass molding die according to the present invention. Figure 7 The diagram schematically illustrates the isometric structure of the outer steel sleeve of a chalcogenide glass molding die according to the present invention.

[0018] Explanation of icon numbers: 1. Upper mold core; 11. First positioning step; 2. Lower mold core; 21. Second positioning step; 3. Mold sleeve; 31. Stress relief groove; 32. Venting channel; 321. Variable diameter section; 4. Diffraction microstructure rings; 5. Outer steel sleeve; 51. Vent hole. Detailed Implementation

[0019] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application. This application can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0020] It should be noted that, in the description of this application, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0021] Furthermore, the terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well.

[0022] It should also be noted that, in the description of this application, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances. All terms used in this application have the same meaning as understood by those skilled in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted with an idealized or highly formalized meaning, unless expressly defined herein.

[0023] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0024] like Figures 1 to 3 As shown, this application provides a chalcogenide glass molding die, including: an upper mold core 1, a lower mold core 2, and a mold sleeve 3; the upper mold core 1 and the lower mold core 2 are joined together to form a mold cavity, which is used to accommodate chalcogenide glass blanks; the mold sleeve 3 is sleeved on the outer periphery of the upper mold core 1 and the lower mold core 2; a stress relief groove 31 is provided on the inner wall of the mold sleeve 3 facing the mold cavity, and the position of the stress relief groove 31 corresponds to the mold parting gap between the upper mold core 1 and the lower mold core 2; an exhaust channel 32 is provided on the mold sleeve 3, the first end of the exhaust channel 32 is connected to the stress relief groove 31, and the second end extends to the outer wall of the mold sleeve 3.

[0025] Specifically, the upper mold core 1 and the lower mold core 2 are joined together to form a mold cavity, which is used to accommodate the chalcogenide glass preform. Under high-temperature molding conditions, the chalcogenide glass preform is placed inside the mold cavity and undergoes a series of processes including heating and softening, mold closing and pressurization, pressure holding and shaping, and cooling and demolding to obtain the molded chalcogenide glass optical element. The mold cavity formed by the joining of the upper mold core 1 and the lower mold core 2 ensures that the preform is subjected to uniform and stable pressure, guaranteeing the molding quality. The mold sleeve 3 is fitted around the outer periphery of the upper mold core 1 and the lower mold core 2. The mold sleeve 3 can be fitted with a clearance fit between itself and the outer periphery of the upper mold core 1 and the lower mold core 2. During the mold closing process, the upper mold core 1 can slide relative to the mold sleeve 3 to move closer to the lower mold core 2 to complete the mold closing and pressurization action. The mold sleeve 3 can wrap and limit the outer sides of the upper mold core 1 and the lower mold core 2, which can constrain the radial displacement deviation of the upper mold core 1 and the lower mold core 2 during the mold closing process and maintain the stability of the mold cavity molding state.

[0026] A stress relief groove 31 is provided on the inner wall of the mold sleeve 3 facing the mold cavity. The location of the stress relief groove 31 corresponds to the parting gap between the upper mold core 1 and the lower mold core 2. During the mold closing process, the mating position of the upper mold core 1 and the lower mold core 2 forms the parting gap. During the high-temperature and high-pressure molding process, the mechanical stress generated by the extrusion of the blank and the thermal stress generated by the temperature change of the mold are prone to accumulate at the parting gap, causing deviations in the fit of the parting surface. This results in quality problems such as edge defects, surface micro-cracks, and deformation of the molded glass element. Based on the constraint and limitation provided by the mold sleeve 3 on the outer side of the upper mold core 1 and the lower mold core 2, this application provides a stress relief groove 31 on the inner wall of the mold sleeve 3 corresponding to the parting gap, which can form a buffer space on the outer side of the parting gap. During the mold closing and pressurization stage, the stress relief groove 31 can share and release the local concentrated extrusion stress at the parting gap, reducing the degree of stress accumulation. During the cooling and shaping stage, the stress relief groove 31 can adapt to the thermal shrinkage difference between the upper mold core 1, the lower mold core 2 and the chalcogenide glass blank, release the residual stress at the interface, alleviate the problems of component cracking and molding deformation, and improve the structural integrity of the molded product.

[0027] The mold sleeve 3 is provided with an exhaust channel 32. The first end of the exhaust channel 32 is connected to the stress relief groove 31, and the second end extends to the outer wall of the mold sleeve 3, forming an exhaust passage that runs through the inside and outside of the mold sleeve 3. During the mold closing and molding process, residual air inside the mold cavity and trace amounts of gaseous substances generated by the heating of the blank will converge to the mold closing and parting gap due to the compression action of the mold closing. In this application, by arranging the stress relief groove 31 and the exhaust channel 32, the gas inside the mold cavity first converges into the stress relief groove 31, and then is discharged outward through the exhaust channel 32, which can smoothly discharge the gas trapped in the mold cavity and alleviate various molding defects caused by air trapped in the mold cavity. Moreover, both the stress relief groove 31 and the exhaust channel 32 are arranged outside the effective molding area of ​​the mold cavity and do not participate in the structural molding of the optical molding area, maintaining the smooth operation of the exhaust structure for a long time and adapting to continuous molding production conditions.

[0028] This application integrates the stress relief groove 31 and the venting channel 32 onto the mold sleeve 3, enabling the same structure to simultaneously perform the dual functions of stress buffering and release and mold cavity gas venting. This avoids the technical problem that the venting function and stress relief function cannot be simultaneously achieved in traditional mold structures, stabilizes the chalcogenide glass molding process, and improves the product molding qualification rate and batch consistency.

[0029] This application provides a chalcogenide glass molding die, comprising: an upper mold core 1, a lower mold core 2, and a mold sleeve 3; the upper mold core 1 and the lower mold core 2, when joined together, form a mold cavity for accommodating chalcogenide glass preforms; the mold sleeve 3 is fitted around the outer periphery of the upper mold core 1 and the lower mold core 2; a stress relief groove 31 is formed on the inner wall of the mold sleeve 3 facing the mold cavity, the position of the stress relief groove 31 corresponding to the parting gap between the upper mold core 1 and the lower mold core 2; an exhaust channel 32 is formed on the mold sleeve 3, the first end of the exhaust channel 32 connecting to the stress relief groove 31, and the second end extending to the outer wall of the mold sleeve 3. This application integrates the dual functions of stress relief at the mold parting position and venting of the mold cavity by forming a stress relief groove 31 on the inner wall of the mold sleeve 3 at the parting gap and providing an exhaust channel 32 connected to the stress relief groove 31. The stress relief groove 31 effectively alleviates stress accumulation at the parting line during molding, reducing defects such as deformation and microcracks in the glass components and ensuring structural accuracy. Simultaneously, the structure connecting the stress relief groove 31 to the venting channel 32 allows for the smooth removal of trapped gas from the mold cavity, preventing molding defects caused by gas buildup. It also prevents softened glass from seeping into and clogging the venting structure, ensuring long-term stable mold operation, effectively improving the molding quality of chalcogenide glass, and enhancing the structural accuracy and yield of the molded components. This application solves the problem that existing mold structures cannot simultaneously address stress relief and venting requirements, resulting in poor microstructural accuracy and low yield of the molded diffraction elements.

[0030] like Figure 3 As shown, in some embodiments, the stress relief groove 31 is annular and is formed circumferentially on the inner wall of the mold sleeve 3.

[0031] Specifically, this application sets the stress relief groove 31 to be annular and is opened along the circumferential direction on the inner wall of the mold sleeve 3. The annular stress relief groove 31 can cover the circumferential mold parting gap formed by the docking of the upper and lower mold cores 2, forming a continuous surrounding buffer space on the outside of the mold cavity. It can uniformly release the compressive stress and thermal stress at various points in the circumferential direction of the mold parting gap, balance the stress state of the mold in the circumferential direction during the molding process, and improve the overall molding uniformity of the component.

[0032] The annular stress relief groove 31 can collect and summarize the gas overflowing from all parts of the mold cavity, so that the gas in the mold parting gap can be smoothly and evenly merged into the groove and discharged outward through the exhaust channel 32, thereby improving the overall exhaust uniformity of the mold cavity, stabilizing the overall molding process environment, and ensuring the consistency of batch molding of chalcogenide glass components.

[0033] like Figure 3 As shown, in some embodiments, the stress relief groove 31 has a rectangular cross-section along the axial direction of the mold sleeve 3.

[0034] Specifically, this application provides that the stress relief groove 31 has a rectangular cross-section along the axial direction of the mold sleeve 3. The rectangular cross-section of the groove structure ensures that the depth and width of the stress relief groove 31 remain consistent along the overall circumference, and that the inner wall of the groove is flat and regular, thereby ensuring consistent stress buffering conditions at all positions along the circumference of the parting gap. Furthermore, the rectangular cross-section can uniformly bear and release the compressive and thermal stresses at various points along the parting gap, stabilizing the forming state of the entire edge of the chalcogenide glass element.

[0035] The rectangular cross-section of the through-channel has a constant flow cross-section, and the gas containment space and conduction conditions are uniform and consistent throughout the circumference. This facilitates the smooth diffusion and uniform collection of gas overflowing from the mold cavity within the channel, avoiding airflow turbulence and localized gas accumulation. At the same time, the rectangular channel facilitates the integral processing and forming of the mold, improving the batch reusability of the mold and making it suitable for the stable molding production of high-precision chalcogenide glass components.

[0036] like Figures 1 to 3 As shown, in some embodiments, the mold sleeve 3 is cylindrical; the exhaust channel 32 extends radially along the cylindrical mold sleeve 3.

[0037] Specifically, this application sets the mold sleeve 3 in a cylindrical shape. The inner wall of the cylindrical mold sleeve 3 has a regular and continuous circumferential contour, which is adapted to the annular arrangement of the annular stress relief groove 31. The cylindrical mold sleeve 3 provides circumferential structural symmetry. The exhaust channel 32 extends along the radial direction of the mold sleeve 3, which can form a radial straight exhaust path from the inside to the outside, shortening the gas outlet stroke and reducing exhaust resistance. This allows the gas collected in the annular stress relief groove 31 to be smoothly and quickly discharged to the outside of the mold sleeve 3 along the radial exhaust channel 32, avoiding gas retention and accumulation in the groove and improving the overall exhaust efficiency.

[0038] like Figure 1 As shown, in some embodiments, the exhaust channels 32 are evenly spaced along the circumferential direction of the annular stress relief groove 31 on the mold sleeve 3.

[0039] Specifically, this application provides exhaust channels 32 that are evenly spaced along the circumferential direction of the annular stress relief groove 31 in the mold sleeve 3. This arrangement can further improve the uniformity of circumferential venting in the mold cavity, allowing the gas overflowing from the parting gap during mold closing to be discharged synchronously and smoothly in all circumferential locations, thereby improving the overall venting throughput and venting stability. At the same time, it allows the gas at each position in the circumferential direction of the annular stress relief groove 31 to be discharged through the nearest corresponding exhaust channel 32, improving venting efficiency.

[0040] like Figure 4 As shown, in some embodiments, the first end of the exhaust channel 32 is provided with a variable diameter section 321, the diameter of the variable diameter section 321 facing the stress relief groove 31 is larger than the diameter of the side away from the stress relief groove 31.

[0041] Specifically, this application provides a variable diameter section 321 at the first end of the exhaust channel 32. The diameter of the variable diameter section 321 facing the stress relief groove 31 is larger than the diameter of the side away from the stress relief groove 31, forming a flow structure adapted to the Venturi airflow characteristics. The large diameter end of the variable diameter section 321 receives the collected gas inside the annular stress relief groove 31, increasing the gas collection and conduction range. During the mold closing and exhaust process, the airflow enters the variable diameter section 321 from the large diameter end. The cross-sectional area inside the variable diameter section 321 gradually decreases, causing the airflow velocity to gradually increase. At the same time, the fluid static pressure decreases, which can form a stable negative pressure suction effect. The negative pressure suction effect can accelerate the discharge of residual gas from the stress relief groove 31 and the parting gap, improving the mold cavity exhaust efficiency.

[0042] like Figure 5 and Figure 6 As shown, in some embodiments, diffraction microstructure rings 4 are provided on the molding end faces of the upper mold core 1 and / or the lower mold core 2 facing the mold cavity.

[0043] Specifically, the diffraction microstructure ring 4 set on the molding end face provides a reference for the formation of the diffraction structure of the chalcogenide glass element. During the molding process, the chalcogenide glass blank softened at high temperature is bonded to the molding end face for shaping, and the diffraction microstructure ring 4 set on the molding end face is used for replication molding, thereby meeting the optical requirements of the chalcogenide glass infrared diffraction element. Furthermore, based on the viscoelastic constitutive model of chalcogenide glass and combined with finite element simulation, during the setting of the diffraction microstructure ring 4, the radial position single ring compensation amount and the ring height single ring compensation amount can be pre-compensated according to the size of the element aperture to correct the deformation deviation during the molding process, ensuring the size, position and surface accuracy of the diffraction microstructure, and the optical indicators of the finished product meet the requirements of high-end infrared equipment.

[0044] In some embodiments, both the upper mold core 1 and the lower mold core 2 are made of tungsten carbide-niobium carbide composite cemented carbide, and a nickel-phosphorus-diamond composite film is provided on the surface of the tungsten carbide-niobium carbide composite cemented carbide; wherein, the coefficients of thermal expansion of the tungsten carbide-niobium carbide composite cemented carbide, the nickel-phosphorus-diamond composite film, and the chalcogenide glass preform are arranged in descending order.

[0045] Specifically, this application sets both the upper mold core 1 and the lower mold core 2 to be made of tungsten carbide-niobium carbide composite cemented carbide. Tungsten carbide-niobium carbide composite cemented carbide has mechanical and thermal properties suitable for high-temperature molding processes of chalcogenide glass. It has strong structural stability and excellent resistance to high-temperature deformation. It can withstand long-term repeated mold closing and extrusion and high and low temperature cycle conditions. It can maintain the structural integrity and dimensional accuracy of the molding end face and the diffraction microstructure ring 4, improve the overall service life of the mold, and ensure the stability and consistency of the mold forming state during mass molding production.

[0046] The surface of the tungsten carbide-niobium carbide composite cemented carbide is coated with a nickel-phosphorus-diamond composite film. By setting the thermal expansion coefficients of the tungsten carbide-niobium carbide composite cemented carbide, the nickel-phosphorus-diamond composite film, and the chalcogenide glass preform in descending order, the nickel-phosphorus-diamond composite film can reduce the difference in thermal expansion coefficients between the tungsten carbide-niobium carbide composite cemented carbide and the chalcogenide glass preform. This creates a thermal transition buffer effect between the hard matrix of the mold core and the glass preform, alleviating the interfacial thermal stress caused by the deformation difference during the entire molding process of heating, cooling and shaping.

[0047] The difference between the coefficient of thermal expansion of the nickel-phosphorus-diamond composite film and that of the chalcogenide glass preform can be no greater than 1.5 × 10⁻⁶. -6 / K is used to avoid molding defects such as cracking of the glass element body, microstructure deformation, and contour incompleteness caused by thermal expansion mismatch during the molding process, thereby improving the molding quality of chalcogenide glass diffraction elements, reducing the defect rate, and ensuring the optical performance of the product and the yield rate of batch production.

[0048] like Figure 1 and 2 As shown, in some embodiments, the upper mold core 1 is provided with a first positioning step 11 at its upper end away from the lower mold core 2; the lower mold core 2 is provided with a second positioning step 21 at its lower end away from the upper mold core 1; the first positioning step 11 and the second positioning step 21 limit the positioning space; the mold sleeve 3 is fitted into the positioning space.

[0049] Specifically, the upper mold core 1 is provided with a first positioning step 11 at its upper end away from the lower mold core 2, and the lower mold core 2 is provided with a second positioning step 21 at its lower end away from the upper mold core 1. The positioning space is limited by the first positioning step 11 and the second positioning step 21. The positioning space can provide limiting constraints on the assembly position of the mold sleeve 3, which can limit the axial displacement and radial movement of the mold sleeve 3 under assembly and molding conditions, avoid misalignment and uneven gaps in the assembly of the mold sleeve 3, ensure the overall coaxiality and assembly symmetry of the mold, ensure the alignment accuracy of the stress relief groove 31 and the mold parting gap, and maintain the working stability of mold venting and stress relief.

[0050] like Figure 7 As shown, in some embodiments, it further includes: an outer steel sleeve 5, which is sleeved on the outside of the first positioning step 11, the mold sleeve 3, and the second positioning step 21; the outer steel sleeve 5 has an exhaust hole 51, and there is a preset gap between the inner wall of the outer steel sleeve 5 and the mold sleeve 3, and the exhaust channel 32 communicates with the exhaust hole 51 through the preset gap.

[0051] Specifically, this application provides an outer steel sleeve 5 that is integrally fitted onto the outside of the first positioning step 11, the mold sleeve 3, and the second positioning step 21. This provides overall coverage and constraint for the positioning steps of the inner mold sleeve 3 and the upper and lower mold cores 2, thereby improving the overall assembly integrity and structural rigidity of the mold, as well as enhancing the overall coaxiality and fitting accuracy of the mold. The outer steel sleeve 5 also provides protection for the internal functional structures, preventing external environmental factors, assembly friction, and cyclic temperature changes from affecting the inner mold core, mold sleeve 3, venting structure, and stress relief groove 31, thus improving the overall structural stability and service life of the mold.

[0052] The pre-set gap between the outer steel sleeve 5 and the mold sleeve 3 can form a buffer gas collection cavity, so that the gas discharged radially from all parts of the mold sleeve 3 can first diffuse to the pre-set gap, and then be discharged outward through the exhaust hole 51 opened by the outer steel sleeve 5. Thus, while ensuring the overall reinforcement and limiting protection function of the outer steel sleeve 5, the gas discharge of the mold is guaranteed.

[0053] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A chalcogenide glass molding die, characterized in that, include: An upper mold core and a lower mold core are joined together to form a mold cavity, which is used to hold chalcogenide glass preforms. A mold sleeve, which is fitted around the outer periphery of the upper mold core and the lower mold core; The inner wall of the mold sleeve facing the mold cavity is provided with a stress relief groove, and the position of the stress relief groove corresponds to the mold parting gap between the upper mold core and the lower mold core. The mold sleeve is provided with an exhaust channel, the first end of which is connected to the stress relief groove, and the second end extends to the outer wall of the mold sleeve.

2. The chalcogenide glass molding die according to claim 1, characterized in that, The stress relief groove is annular and is formed circumferentially on the inner wall of the mold.

3. The chalcogenide glass molding die according to claim 2, characterized in that, The stress relief groove has a rectangular cross-section along the axial direction of the mold sleeve.

4. The chalcogenide glass molding die according to claim 2, characterized in that, The mold sleeve is cylindrical; The exhaust channel extends radially along the cylindrical mold sleeve.

5. The chalcogenide glass molding die according to claim 4, characterized in that, The exhaust channels are evenly spaced along the circumferential direction of the annular stress relief groove in the mold sleeve.

6. The chalcogenide glass molding die according to claim 1, characterized in that, The first end of the exhaust channel is provided with a variable diameter section, the diameter of the variable diameter section facing the stress relief groove is larger than the diameter of the side away from the stress relief groove.

7. The chalcogenide glass molding die according to claim 1, characterized in that, The upper mold core and / or the lower mold core are provided with diffractive microstructure rings on their forming end faces toward the mold cavity.

8. The chalcogenide glass molding die according to claim 1, characterized in that, Both the upper mold core and the lower mold core are made of tungsten carbide-niobium carbide composite cemented carbide, and the surface of the tungsten carbide-niobium carbide composite cemented carbide is provided with a nickel-phosphorus-diamond composite film layer. The coefficients of thermal expansion of the tungsten carbide-niobium carbide composite cemented carbide, the nickel-phosphorus-diamond composite film, and the chalcogenide glass preform are arranged in descending order.

9. The chalcogenide glass molding die according to claim 1, characterized in that, The upper mold core is provided with a first positioning step at its upper end away from the lower mold core; The lower mold core is provided with a second positioning step at its lower end, which is away from the upper mold core; The first positioning step and the second positioning step limit the positioning space; The mold is fitted onto the positioning space.

10. The chalcogenide glass molding die according to claim 9, characterized in that, Also includes: An outer steel sleeve is fitted over the outside of the first positioning step, the mold sleeve, and the second positioning step; The outer steel sleeve has an exhaust hole, and there is a preset gap between the inner wall of the outer steel sleeve and the mold sleeve. The exhaust channel communicates with the exhaust hole through the preset gap.

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