CN114853481B

CN114853481B - Hardness-improved oxidation-resistant material, and preparation method and application thereof

Info

Publication number: CN114853481B
Application number: CN202210451971.2A
Authority: CN
Inventors: 陈亚兵; 李倩倩; 付弦; 许仁; 王伟
Original assignee: Weidali Technology Co ltd
Current assignee: Weidali Technology Co ltd
Priority date: 2022-04-27
Filing date: 2022-04-27
Publication date: 2023-11-07
Anticipated expiration: 2042-04-27
Also published as: CN114853481A

Abstract

The invention relates to a hardness-improved oxidation-resistant material, and a preparation method and application thereof. The boron nitride, the mica, the heat conducting agent and the microcrystalline glass are matched for use, and the mass percentages of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass are respectively controlled to be 30% -60%, 35% -60%, 0% -20% and 0% -10%, so that the material with good oxidation resistance and obvious hardness improvement is obtained. The hardness-improved oxidation-resistant material is used in a hot bending die, so that the hardness and oxidation resistance of the hot bending die can be effectively improved.

Description

Hardness-improved oxidation-resistant material, and preparation method and application thereof

Technical Field

The invention relates to the technical field of materials, in particular to a hardness-improved oxidation-resistant material, and a preparation method and application thereof.

Background

With the progress of glass processing technology, products including curved glass are increasing, and thus, the demand for curved glass is increasing. For example, electronic products such as mobile phones, computers, televisions and the like using 3D glass as a cover plate are popular with consumers, and the demand for 3D glass is increasing.

In the processing of curved glass, a hot bending die is a key processing component. The glass can be processed into curved glass meeting the radian requirement through the use of a hot bending die. On the basis of materials selected for the hot bending die, the conventional hot bending die is usually prepared from graphite. Although graphite molds have the advantages of good heat conduction performance, good lubricity, moderate strength and the like, the graphite molds often have the problems of low hardness, no oxidization resistance and the like due to the restriction of the performance, and the existence of the problems has great influence on the service life and the service performance of the graphite molds.

Disclosure of Invention

Based on this, it is necessary to provide a hardness-improved oxidation-resistant material, and a preparation method and application thereof.

In order to solve the technical problems, the technical scheme of the invention is as follows:

the hardness-improved oxidation-resistant material is prepared from the following raw materials in percentage by mass: 30-60% of boron nitride, 35-60% of mica, 0-20% of heat conducting agent and 0-10% of glass ceramic.

In one embodiment, the boron nitride is hexagonal boron nitride; and/or the Mohs hardness of the boron nitride is 1-2; and/or the mica has a mohs hardness of 2 to 3; and/or the thermally conductive agent comprises at least one of aluminum nitride and silicon carbide.

In one embodiment, the raw materials further comprise an anti-settling agent, wherein the anti-settling agent accounts for 0.5-2% by mass of the sum of the mass of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass; and/or the number of the groups of groups,

the raw materials also comprise a water reducer, wherein the mass percent of the water reducer is 0.2-1% in terms of the mass percent of the sum of the masses of boron nitride, mica, heat conducting agent and microcrystalline glass; and/or the number of the groups of groups,

the raw materials also comprise a dispersing agent, wherein the mass percent of the dispersing agent is 5-30% in terms of the mass percent of the sum of the masses of boron nitride, mica, heat conducting agent and microcrystalline glass; and/or the number of the groups of groups,

the raw materials also comprise an antifoaming agent, wherein the mass percent of the antifoaming agent is 0.1-1 percent in terms of the mass percent of the sum of the masses of boron nitride, mica, heat conducting agent and microcrystalline glass.

A preparation method of a hardness-improved oxidation-resistant material comprises the following steps:

preparing materials according to the mass percentage of 30-60% of boron nitride, 35-60% of mica, 0-20% of heat conducting agent and 0-10% of glass ceramics;

mixing the boron nitride, the mica, the heat conducting agent and the glass ceramic.

In one embodiment, the mixing of the boron nitride, the mica, the heat conducting agent and the glass ceramic further comprises the following steps:

mixing the mixed mixture with an anti-settling agent, a water reducing agent, a dispersing agent and a defoaming agent;

wherein, the weight percentage of the anti-settling agent is 0.5-2%, the weight percentage of the water reducing agent is 0.2-1%, the weight percentage of the dispersing agent is 5-30%, and the weight percentage of the defoaming agent is 0.1-1%, calculated by the weight percentage of the sum of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass.

The hardness-improved oxidation-resistant material described in any one of the above embodiments or the hardness-improved oxidation-resistant material obtained by the preparation method described in any one of the above embodiments is used for preparing a hot-bending die.

In one embodiment, the application comprises the steps of:

forming the hardness-improved oxidation-resistant material to prepare a green body;

and sintering the green body.

In one embodiment, the sintering process is at a temperature of 1000 ℃ to 1400 ℃.

In one embodiment, the molding process includes the steps of:

filling the hardness-improved oxidation-resistant material into a powder forming die, and then pressing and forming; or,

mixing the boron nitride, the mica, the heat conducting agent and the microcrystalline glass to prepare a mixture;

mixing the mixture with an anti-settling agent, a water reducing agent, a dispersing agent and a defoaming agent to prepare slurry; the weight percentage of the anti-settling agent is 0.5-2%, the weight percentage of the water reducing agent is 0.2-1%, the weight percentage of the dispersing agent is 5-30%, and the weight percentage of the defoaming agent is 0.1-1%, calculated by the weight percentage of the sum of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass;

the slurry is injected into a slurry forming die and then dried and formed.

A hot-bending die prepared from the hardness-improved oxidation-resistant material comprising the hardness-improved oxidation-resistant material described in any one of the above embodiments or the hardness-improved oxidation-resistant material obtained by the preparation method described in any one of the above embodiments.

The inventor researches on a hot bending die of curved glass, and found that the conventional graphite die has unsatisfactory performance, such as lower hardness, in the use process, and the problem of die abrasion easily occurs when the conventional graphite die is used for hot bending forming of the curved glass. For another example, graphite molds have poor oxidation resistance, and the molds are susceptible to oxidative damage during hot bending of curved glass. Based on the above, the inventors started from the material of the hot bending die, and used boron nitride, mica, a heat conductive agent and glass ceramics in combination, and controlled the mass percentages of boron nitride, mica, heat conductive agent and glass ceramics to be 30% -60%, 35% -60%, 0% -20% and 0% -10%, respectively, thereby obtaining the material with good oxidation resistance and obvious hardness improvement. The hardness-improved oxidation-resistant material is used in a hot bending die, so that the hardness and oxidation resistance of the hot bending die can be effectively improved.

In the preparation method of the hardness-improved oxidation-resistant material, 30-60%, 35-60%, 0-20% and 0-10% of boron nitride, mica, a heat conducting agent and microcrystalline glass are prepared according to mass percentages respectively, and then the boron nitride, the mica, the heat conducting agent and the microcrystalline glass are mixed, so that the preparation method is simple and feasible and is suitable for industrial production.

Detailed Description

The following detailed description of the present invention will provide further details in order to make the above-mentioned objects, features and advantages of the present invention more comprehensible. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

An embodiment of the present invention provides a hardness-improved oxidation resistant material. The hardness-improved oxidation-resistant material is prepared from the following raw materials in percentage by mass: 30-60% of boron nitride, 35-60% of mica, 0-20% of heat conducting agent and 0-10% of glass ceramic. In the hardness-improved oxidation-resistant material of the embodiment, the boron nitride, the mica, the heat conducting agent and the microcrystalline glass are used in a matching manner, and the mass percentages of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass are respectively controlled to be 30% -60%, 35% -60%, 0% -20% and 0% -10%, so that the material with good oxidation resistance and obvious hardness improvement is obtained. The hardness-improved oxidation-resistant material is used in a hot bending die, so that the hardness and oxidation resistance of the hot bending die can be effectively improved.

In the traditional graphite mould, the hardness of graphite is lower, the Mohs hardness of the graphite is about 1, the interior of the graphite is of a two-dimensional lamellar structure, layers are connected by virtue of Van der Waals force, and therefore the graphite mould is easy to suffer from abrasion problems such as lamellar peeling and powder falling in the use process. The abrasion problem not only reduces the service life of the graphite mold, but also has adverse effects on the quality of curved glass products. The hardness-improved oxidation-resistant material in the embodiment can effectively improve the hardness of the hot bending die through the matching use of boron nitride, mica, a heat conducting agent and microcrystalline glass. And the Mohs hardness of the hot bending die prepared from the hardness-improved oxidation-resistant material reaches about 4 to 5 by controlling the proportion of the raw materials. And for the processing of curved glass (glass hardness is generally more than or equal to 4), the glass has better suitability for the forming of the curved glass under the condition of Mohs hardness of 4-5. Too low a mohs hardness may cause wear of the hot bending mold and too high a mohs hardness may increase the risk of damage to the glass during hot bending. Meanwhile, the Mohs hardness of the hot bending die prepared from the hardness-improved oxidation-resistant material reaches about 4-5, and the hot bending die is convenient to process, and the Mohs hardness is too high or too low, so that the hot bending die is inconvenient to process. The hot bending die prepared from the hardness-improved oxidation-resistant material in the embodiment is better matched with the processing of the curved glass on the basis of keeping the self hardness, so that the service life of the die is prolonged, and the effect of effectively keeping the processing yield of the curved glass is achieved.

In addition, in the conventional graphite mold, the oxidation resistance of graphite is poor. Particularly, under the high-temperature condition of high-temperature hot bending, the problem of oxidization is more easy to occur, and the occurrence of the problem of oxidization can bring serious adverse effects to the performance and service life of the graphite mold. In order to reduce the influence of graphite oxidation, in the actual production process, a closed cavity is generally adopted for hot bending, and protective gas is filled in the closed cavity to prevent graphite oxidation. However, in the production process, the feeding and discharging operation is inevitably performed, so that oxygen is inevitably introduced into the closed cavity, and further oxidation of the graphite mold is caused. Another method for preventing graphite oxidation is to form an oxidation-resistant protective layer on the surface of the graphite mold. The method can avoid oxidation of graphite to a certain extent, but can greatly improve the production cost of the curved glass. Meanwhile, the melting point of graphite is high, sintering of a hot bending die prepared from graphite is difficult, and the preparation cost of the graphite hot bending die is high, so that the production cost of curved glass can be increased. The hardness-improved oxidation-resistant material in the embodiment fundamentally solves the problem of die oxidation from the material of the hot bending die through the matching use of boron nitride, mica, a heat conducting agent and microcrystalline glass. The hot bending die prepared from the hardness-improved oxidation-resistant material has good oxidation resistance, and can keep stable oxidation resistance even under the high-temperature condition of an air atmosphere. This has important significance for the extension of the service life of the hot bending die and the reduction of the processing cost of the curved glass. For example, the glass may be hot-formed without the addition of a shielding gas.

In a specific example, the hardness-improved oxidation resistant material is prepared from the following raw materials in percentage by mass: 30-60% of boron nitride, 35-60% of mica, 0-20% of heat conducting agent and 0-10% of glass ceramic. In this example, a material having high hardness and excellent oxidation resistance can be obtained by only mixing boron nitride, mica, a heat conductive agent, and glass ceramic.

As some selected examples of the mass percent of boron nitride in the feedstock, the mass percent of boron nitride may be, but is not limited to, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. It will be appreciated that other suitable selections of the mass percent of boron nitride may be made at 30% to 60%.

As some selected examples of the mass percent of mica in the raw material, the mass percent of mica may be, but is not limited to, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, or 60%. It will be appreciated that other suitable selections of the mass percent of mica may be made at between 35% and 60%.

As some selected examples of the mass percent of the heat transfer agent in the feedstock, the mass percent of the heat transfer agent may be, but is not limited to, 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%. It will be appreciated that other suitable selections of the mass percent of the thermally conductive agent may be made between 0 and 20%.

As some examples of choices of the mass percentage of the glass-ceramic in the raw material, the mass percentage of the glass-ceramic may be, but is not limited to, 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. It will be appreciated that other suitable selections of glass ceramics may be made at a mass percentage of 0 to 10%.

Further, the raw materials of the hardness-improved oxidation-resistant material comprise at least one of a heat conduction agent and glass ceramics, namely, the mass percentages of the heat conduction agent and the glass ceramics are different from 0. Furthermore, the raw materials of the hardness-improved oxidation-resistant material comprise a heat conduction agent and microcrystalline glass, namely the mass percent of the heat conduction agent and the microcrystalline glass in the raw materials of the hardness-improved oxidation-resistant material is more than 0. The addition of the heat conducting agent can improve the heat conducting performance of the hardness-improved oxidation-resistant material and the heat conducting coefficient of the hardness-improved oxidation-resistant material, so that the hardness-improved oxidation-resistant material is more suitable for a hot bending die of curved glass. The addition of the glass ceramics is easy to soften in the sintering process of preparing the hot bending die, and forms crystalline phase after sintering, thereby being beneficial to keeping the stability of the molding of the hot bending die, not reducing the melting point after sintering, and not adversely affecting the performance of the material.

In one specific example, the boron nitride is hexagonal boron nitride. Further, the Mohs hardness of the boron nitride is 1 to 2.

Alternatively, the mica is a hexagonal platelet structure. The Mohs hardness of the mica is 2-3. Optionally, the thermally conductive agent comprises at least one of aluminum nitride and silicon carbide.

In a specific example, the preparation raw material of the hardness-improved oxidation-resistant material further includes an anti-settling agent, wherein the anti-settling agent accounts for 0.5% -2% by mass of the sum of the mass of the boron nitride, the mica, the heat conducting agent and the glass ceramic, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2% by mass of the anti-settling agent. It will be appreciated that the mass percent of the anti-settling agent may be selected in other suitable ranges from 0.5% to 2%. Further, the anti-settling agent includes at least one of a polyamide wax and fumed silica.

In a specific example, the preparation raw materials of the hardness-improved oxidation-resistant material further include a water reducer, wherein the water reducer accounts for 0.2% -1% by mass of the sum of the masses of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass, for example, the water reducer accounts for 0.2%, 0.3%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1% by mass and the like. It will be appreciated that the mass percent of the water reducing agent may be selected in other suitable ranges from 0.2% to 1%. Further, the water reducing agent comprises at least one of a ceramic water reducing agent, a phosphate comb polymer, a polycarboxylic acid water reducing agent, a sulfamate water reducing agent and a naphthalene water reducing agent.

In a specific example, the preparation raw material of the hardness-improved oxidation-resistant material further includes a dispersant, wherein the mass percentage of the dispersant is 5% -30% by mass of the sum of the mass percentages of the boron nitride, the mica, the heat conductive agent and the glass ceramic, for example, the mass percentage of the dispersant is 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28% or 30% and the like. It will be appreciated that the mass percent of dispersant may be selected in other suitable ranges from 5% to 30%. Further, the dispersant includes at least one of water and an organic solvent. The organic solvent is at least one of methanol and ethanol.

In a specific example, the preparation raw material of the hardness-improved oxidation-resistant material further comprises an antifoaming agent, wherein the mass percentage of the antifoaming agent is 0.1% -1% in terms of the mass percentage of the sum of the mass percentages of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass, for example, the mass percentage of the water reducing agent is 0.1%, 0.2%, 0.3%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%, etc. It will be appreciated that the mass percent of defoamer may be selected in other suitable ranges from 0.1% to 1%. Further, the defoamer includes a modified silicone defoamer.

In yet another embodiment of the present invention, a method for preparing an improved hardness oxidation resistant material is provided. The preparation method comprises the following steps: preparing materials according to the mass percentage of 30-60% of boron nitride, 35-60% of mica, 0-20% of heat conducting agent and 0-10% of glass ceramics; mixing boron nitride, mica, a heat conducting agent and microcrystalline glass. The preparation method is simple and feasible, and is suitable for industrial production.

In a specific example, the mixing of boron nitride, mica, a heat conducting agent and glass ceramic further comprises the following steps: mixing the mixed mixture with an anti-settling agent, a water reducing agent, a dispersing agent and a defoaming agent; wherein, the weight percentage of the anti-settling agent is 0.5 to 2 percent, the weight percentage of the water reducing agent is 0.2 to 1 percent, the weight percentage of the dispersing agent is 5 to 30 percent, and the weight percentage of the defoaming agent is 0.1 to 1 percent based on the sum of the weight percentages of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass. The addition of the anti-settling agent, the water reducing agent, the dispersing agent and the defoaming agent can improve the fluidity and stability of the sizing agent in the process of preparing the hot bending die, thereby improving the performances such as the density and the strength of the hot bending die. Optionally, when the mixed mixture is mixed with the anti-settling agent, the water reducing agent, the dispersing agent and the defoaming agent, the anti-settling agent, the water reducing agent, the dispersing agent and the defoaming agent are sequentially added into the mixed mixture.

Further, the method comprises the following steps before mixing the mixed mixture with the anti-settling agent, the water reducing agent, the dispersing agent and the defoaming agent: mixing the mixture with ball milling liquid, and ball milling for 1-10 h, wherein the ball milling liquid accounts for 20-60% of the mixture by mass. The ball milling liquid comprises at least one of water and an organic solvent. The organic solvent is at least one of methanol and ethanol. The particle size of the mixture can be controlled by ball milling (wet milling) so that the mixture is more suitable for subsequent processing. Alternatively, the particle size of the mixture is made to be 0.5 μm to 500 μm by ball milling. It will be appreciated that the mixture is dried after wet milling, and the mixture is sieved through a sieve after drying. Optionally, the mixture is screened using a 200 mesh screen.

The invention also provides an application of the hardness-improved oxidation-resistant material or the hardness-improved oxidation-resistant material obtained by the preparation method in preparing a hot bending die.

Specifically, the application in the present embodiment includes the steps of: forming the hardness-improved oxidation-resistant material to prepare a green body; and sintering the green body. Alternatively, the sintering process is carried out at a temperature of 1000 ℃ to 1400 ℃. For example, the sintering process may be, but is not limited to, 1000 ℃, 1050 ℃, 1100 ℃, 1150 ℃, 1200 ℃, 1250 ℃, 1260 ℃, 1280 ℃, 1300 ℃, 1350 ℃, 1400 ℃. Alternatively, the temperature of the sintering process may be selected within the range of 1000 ℃ to 1400 ℃. Optionally, the sintering treatment time is 2-24 hours. For example, the sintering treatment time may be 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, 24h, or the like. Alternatively, the sintering process time may be selected within the range of 2h to 24h.

It is understood that the sintering process is performed in a vacuum furnace or an atmosphere furnace. When the sintering treatment is performed in an atmosphere furnace, the atmosphere in the atmosphere furnace is a hydrogen atmosphere, a nitrogen atmosphere, or an argon atmosphere.

In a specific example, the shaping process may be powder shaping or slurry shaping. In powder molding, solid powder is used as a raw material and molded in a powder molding die. When the sizing agent is formed, sizing agent is taken as a raw material to be formed in a sizing agent forming die.

Specifically, when powder molding is employed. The molding process comprises the following steps: the hardness-improved oxidation-resistant material is put into a powder forming die and then pressed and formed. It will be appreciated that the hardness-modified oxidation-resistant material is formed into a solid powder prior to compression molding. The solid powder can be prepared by ball milling. It will also be appreciated that the hardness-modified oxidation-resistant material is dried before compression molding and then formed into a solid powder. Alternatively, the particle size of the solid powder produced is 0.5 μm to 5. Mu.m. When powder molding is employed. The preparation raw materials of the hardness-improved oxidation-resistant material comprise 30% -60% of boron nitride, 35% -60% of mica, 0% -20% of heat conducting agent, 0% -10% of glass ceramic, and/or an anti-settling agent, and/or a water reducing agent, and/or a dispersing agent, and/or a defoaming agent.

Specifically, when slurry molding is employed. The molding process comprises the following steps: mixing boron nitride, mica, a heat conducting agent and microcrystalline glass to prepare a mixture; mixing the mixture with an anti-settling agent, and/or a water reducing agent, and/or a dispersing agent and/or a defoaming agent to prepare slurry; wherein, the weight percentage of the anti-settling agent is 0.5 to 2 percent, the weight percentage of the water reducing agent is 0.2 to 1 percent, the weight percentage of the dispersing agent is 5 to 30 percent, and the weight percentage of the defoaming agent is 0.1 to 1 percent based on the sum of the weight percentages of the boron nitride, the mica, the heat conducting agent and the microcrystalline glass; the slurry is injected into a slurry forming mold, and then dried and formed. Optionally, the drying and forming are carried out by naturally airing in the air for 1-3 days. Directly demolding after drying to prepare a green body. Alternatively, the slurry forming mold includes a plaster mold or a super absorbent plastic resin mold, or the like.

It will be appreciated that after sintering the green body, CNC trimming, polishing, etc. steps may also be performed to make the hot-bending die meet design requirements.

Still another embodiment of the present invention provides a hot bending die. The hot bending die is prepared from the hardness-improved oxidation-resistant material or the hardness-improved oxidation-resistant material obtained by the preparation method.

Still another embodiment of the present invention provides a hot bending die. The hot bending die is prepared from the hardness-improved oxidation resistant material or the hardness-improved oxidation resistant material obtained by the preparation method.

The following are specific examples.

Example 1

The preparation method of the hardness-improved oxidation-resistant material in the embodiment comprises the following steps:

s101: the mixture is prepared and mixed according to 50% of hexagonal boron nitride, 40% of mica, 5% of silicon carbide and 5% of microcrystalline glass by mass percent.

S102: and (3) adding ethanol accounting for 50% of the mass of the mixture into the mixture obtained in the step (S101) for ball milling for 5 hours. Ball milling, drying, and sieving with 200 mesh sieve to obtain powder.

S103: and (3) adding polyamide wax, a ceramic water reducer and deionized water into the powder obtained in the step (S102), stirring uniformly, and then adding a modified organic silicon defoamer for continuous stirring to obtain slurry. Wherein, the weight percentage of the anti-settling agent is 0.8%, the weight percentage of the ceramic water reducer is 0.6%, the weight percentage of the deionized water is 20%, and the weight percentage of the defoamer is 0.1% based on the sum of the weight percentages of hexagonal boron nitride, mica, silicon carbide and microcrystalline glass.

The preparation method of the hot bending die in the embodiment comprises the following steps:

pouring the slurry obtained in the step S103 into a gypsum mold, standing for 2 days at room temperature, demolding to obtain a green body, sintering the green body in a vacuum furnace at 1200 ℃ for 6 hours to obtain a mold blank, and performing CNC trimming and polishing on the surface of the mold blank to obtain the hot bending mold in the embodiment.

Example 2

Compared with example 1, the difference of this example is that 30% of hexagonal boron nitride, 60% of mica, 5% of silicon carbide and 5% of microcrystalline glass are prepared in percentage by mass.

Example 3

Compared with example 1, the difference of this example is that 55% of hexagonal boron nitride, 35% of mica, 5% of silicon carbide and 5% of microcrystalline glass are prepared in percentage by mass.

Example 4

Compared with example 1, the difference of this example is that 50% of hexagonal boron nitride, 43% of mica, 5% of silicon carbide and 2% of microcrystalline glass are prepared in percentage by mass. The sintering temperature was 1260 ℃.

Example 5

Compared with example 1, the difference of this example is that 50% of hexagonal boron nitride, 45% of mica, 5% of silicon carbide and 0% of microcrystalline glass are prepared in percentage by mass. The sintering temperature was 1300 ℃.

Example 6

Compared with example 1, the difference of this example is that 50% of hexagonal boron nitride, 45% of mica, 0% of silicon carbide and 5% of microcrystalline glass are prepared in percentage by mass.

Comparative example 1

The hot bending die in the comparative example is obtained by sintering, CNC trimming and polishing graphite. The sintering temperature was 2200 ℃.

Comparative example 2

Compared with example 1, the difference of this example is that 50% of cubic boron nitride, 40% of mica, 5% of silicon carbide and 5% of microcrystalline glass are prepared in percentage by mass. The sintering temperature was 1700 ℃.

Comparative example 3

Compared with example 1, the difference of this example is that 100% of hexagonal boron nitride is prepared in mass percent. The sintering temperature was 1700 ℃.

Comparative example 4

Compared with example 1, this example differs in that 100% of mica is prepared in mass percent. The sintering temperature was 1000 ℃.

Test case

The hot-bending molds obtained in examples 1 to 6 and comparative examples 1 to 4 were subjected to oxidation resistance test, mohs hardness test, flexural strength test, thermal conductivity test and cost evaluation, respectively.

The method for testing the oxidation resistance comprises the following steps: treating at 800 ℃ in air for 5 hours, and testing the weight loss rate before and after the test.

The mohs hardness test method comprises the following steps: polishing the plane of the hot bending die, and scoring the test sample by selecting Mohs hardness pens with different hardness (from low to high), wherein the scratch is displayed to judge that the hardness of the sample is lower than that of the Mohs hardness pen.

The bending strength testing method comprises the following steps: and testing the bending strength of the material by using a three-point bending test method.

The heat conductivity testing method comprises the following steps: selecting a testing instrument Hot Disk (TPS 2500), and testing by referring to the ISO22007-2 standard;

the cost is comprehensively judged according to the price of the raw materials and the service life, and the test results are shown in the following table.

As shown in the table, the hot bending dies in examples 1 to 6 have no weight loss at 800 ℃ for 5 hours, the glass products cannot be bad due to powder falling of the dies in the hot bending process, and the hot bending dies cannot be oxidized directly at the temperature of 800 ℃. Meanwhile, the mode hardness of the hot bending die in examples 1 to 6 is matched with the Mohs hardness of the glass, so that the yield of the glass product can be better maintained. The hot-bending dies in examples 1 to 6 are shown to exhibit better properties in terms of hardness and oxidation resistance.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. The scope of the invention is, therefore, indicated by the appended claims, and the description may be intended to interpret the contents of the claims.

Claims

1. The hardness-improved oxidation-resistant material is characterized by being prepared from the following raw materials in percentage by mass: 30-60% of boron nitride, 35-60% of mica, 0-20% of heat conducting agent and 1-10% of glass ceramics; the boron nitride is hexagonal boron nitride, the Mohs hardness of the boron nitride is 1-2, and the Mohs hardness of the mica is 2-3.

2. The hardness-improved oxidation-resistant material according to claim 1, wherein said heat conductive agent comprises at least one of aluminum nitride and silicon carbide.

3. The hardness-improved oxidation-resistant material according to any one of claims 1 to 2, wherein the raw material further comprises an anti-settling agent, wherein the anti-settling agent is 0.5 to 2 mass percent based on the mass percent of the sum of the mass of boron nitride, mica, heat conductive agent and glass ceramic; and/or the number of the groups of groups,

4. The preparation method of the hardness-improved oxidation-resistant material is characterized by comprising the following steps of:

according to the mass percentage, preparing materials according to 30-60% of boron nitride, 35-60% of mica, 0-20% of heat conducting agent and 1-10% of microcrystalline glass;

mixing the boron nitride, the mica, the heat conducting agent and the glass ceramic; the boron nitride is hexagonal boron nitride, the Mohs hardness of the boron nitride is 1-2, and the Mohs hardness of the mica is 2-3.

5. The method for producing an oxidation-resistant material with improved hardness according to claim 4, wherein after mixing said boron nitride, said mica, said heat conductive agent and said glass ceramic, further comprising the steps of:

6. Use of the hardness-improved oxidation-resistant material according to any one of claims 1 to 3 or the hardness-improved oxidation-resistant material obtained by the production method according to any one of claims 4 to 5 for producing hot-bending dies.

7. The use according to claim 6, comprising the steps of:

and sintering the green body.

8. The use according to claim 7, wherein the sintering treatment is carried out at a temperature of 1000 ℃ to 1400 ℃.

9. Use according to any one of claims 7 to 8, wherein the shaping process comprises the steps of:

filling the hardness-improved oxidation-resistant material into a powder forming die, and then pressing and forming; or alternatively, the first and second heat exchangers may be,

the slurry is injected into a slurry forming die and then dried and formed.

10. A hot-bending die prepared from the hardness-improved oxidation-resistant material according to any one of claims 1 to 3 or the preparation method according to any one of claims 4 to 5.