CN114589819A - Hot bending die and preparation method thereof, curved ceramic part and electronic equipment - Google Patents

Abstract

The application provides a hot bending die for ceramic member's hot bending, hot bending die has the holding chamber, the holding chamber is used for the holding ceramic member, hot bending die includes the mould body, and sets gradually the mould body is close to the silica layer and the at least one deck barrier layer of holding chamber one side, the material of mould body includes silicon-containing compound, the material of barrier layer includes oxide ceramic material and does not contain silica. The binding force between silica and mould body and barrier layer is good among this hot-bending mould, promotes overall structure's stability and life to the barrier layer can obstruct ceramic member and mould body in the hot-bending mould use and take place the reaction, avoids ceramic member sticking die, and easy drawing of patterns guarantees the production yield of ceramic member. The application also provides a preparation method of the hot bending die, the curved surface ceramic part and the electronic equipment.

Description

Hot bending die and preparation method thereof, curved ceramic part and electronic equipment

technical field

The application belongs to the technical field of electronic products, and in particular relates to a hot bending die and a preparation method thereof, a curved ceramic piece and electronic equipment.

Background technique

Ceramic materials have the advantages of high hardness, good toughness and wear resistance, and are often used in electronic equipment in recent years. With the continuous change of the appearance design of electronic equipment, more and more places need to use curved parts. Therefore, the preparation of curved ceramic parts is of great significance for its application in electronic devices.

SUMMARY OF THE INVENTION

In view of this, the present application provides a hot bending mold and a method for preparing a hot bending mold. By arranging a silicon dioxide layer and a barrier layer on the mold body, the hot bending mold has excellent mechanical properties, structural stability and chemical properties. Stability, so that it can be used for hot bending of ceramic parts to prepare curved ceramic parts, and the mold does not react with the ceramic parts, ensuring the generation yield of the curved ceramic parts, which is beneficial to the application of the curved ceramic parts in electronic equipment.

In a first aspect, the present application provides a hot bending die for hot bending a ceramic piece, the hot bending die has a accommodating cavity, the accommodating cavity is used for accommodating the ceramic piece, the hot bending die The mold includes a mold body, a silicon dioxide layer and at least one barrier layer sequentially arranged on the side of the mold body close to the accommodating cavity. The material of the mold body includes a silicon-containing compound, and the material of the barrier layer is Contains oxide ceramic material and does not contain silica.

In a second aspect, the application provides a method for preparing a hot bending die, comprising:

providing a mold body precursor, the material of the mold body precursor includes a silicon-containing compound, and the mold body precursor has a accommodating cavity;

calcining the mold body precursor to generate a silicon dioxide layer on the surface of the mold body precursor near the accommodating cavity;

At least one barrier layer is formed on the surface of the silicon dioxide layer, and the material of the barrier layer includes oxide ceramic material and does not contain silicon dioxide to obtain a hot bending mold.

In a third aspect, the present application provides a curved ceramic piece obtained by using the hot bending die described in the first aspect.

In a fourth aspect, the present application provides an electronic device, including the curved ceramic piece described in the third aspect.

The application provides a hot bending mold, in which the silicon dioxide, the mold body and the barrier layer have good bonding force, improve the stability and service life of the overall structure, and have stable performance of the barrier layer, which can block heat During the use of the bending mold, the ceramic parts contact and react with the mold body and the silicon dioxide layer, so as to avoid the ceramic parts from sticking to the mold, easy to demould, and ensure the production yield of the ceramic parts. The preparation method of the hot bending mold is simple and the operation is convenient. The surface of the curved ceramic piece prepared by the hot bending die is smooth, no bubbles are generated, the product quality is excellent, and the product can be applied to electronic equipment to improve the appearance and performance of the electronic equipment.

Description of drawings

In order to describe the technical solutions in the embodiments of the present application more clearly, the accompanying drawings required to be used in the embodiments of the present application will be described below.

FIG. 1 is a schematic diagram of a hot bending die provided by an embodiment of the present application.

FIG. 2 is a schematic structural diagram of a hot bending die provided by an embodiment of the present application.

FIG. 3 is a schematic structural diagram of a hot bending die provided by an embodiment of the present application.

FIG. 4 is a schematic structural diagram of a hot bending die provided by another embodiment of the present application.

FIG. 5 is a flowchart of a method for preparing a hot bending die provided by an embodiment of the present application.

FIG. 6 is a curved ceramic piece provided by an embodiment of the present application.

FIG. 7 is an enlarged cross-sectional view taken along the line A-A in FIG. 6 .

FIG. 8 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

Label description:

Mold body-11, female mold-111, punch-112, silicon dioxide layer-12, barrier layer-13, accommodating cavity-10 Hot bending mold-100, curved ceramic piece-200.

Detailed ways

The following are the preferred embodiments of the present application. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can be made, and these improvements and modifications are also regarded as the present invention. The scope of protection applied for.

The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are only examples and are not intended to limit the application. Furthermore, this application may repeat reference numerals and/or reference letters in different instances for the purpose of simplicity and clarity, and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, this application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

Please refer to FIG. 1 , which is a schematic diagram of a hot bending mold according to an embodiment of the present application, wherein the hot bending mold 100 has an accommodating cavity 10 , and the accommodating cavity 10 is used for accommodating a ceramic piece. Please refer to FIG. 2 , which is a schematic structural diagram of a hot bending mold according to an embodiment of the application, wherein the hot bending mold 100 includes a mold body 11 and a silicon dioxide layer sequentially disposed on the side of the mold body 11 close to the accommodating cavity 10 12 and at least one barrier layer 13, the material of the mold body 11 includes a silicon-containing compound, and the material of the barrier layer 13 includes an oxide ceramic material and does not contain silicon dioxide. The material of the mold body 11 includes a silicon-containing compound, so that the hot bending mold 100 has excellent strength, thermal shock resistance, high temperature corrosion resistance and low high temperature creep rate; the silicon dioxide layer 12 is connected to the mold body 11 and the barrier layer. The bonding force between 13 is good, which improves the stability and service life of the overall structure; the barrier layer 13 can block the direct contact between the ceramic piece and the mold body 11 and the silicon dioxide layer 12, and avoid the ceramic piece and the mold body 11 and silicon dioxide. The reaction occurs between the layers 12, so as to avoid the phenomenon of ceramic parts sticking to the mold and the occurrence of poor surface of the ceramic parts, so that the ceramic parts after hot bending are easy to demould, and the surface of the ceramic parts is good, ensuring the production yield of the ceramic parts, while blocking the layer. The setting of 13 enables the hot bending die 100 to be directly placed in the air atmosphere when in use, the barrier layer 13 has stable performance, is not easy to react in the air, and can still play a blocking role, so that the hot bending process does not need to be carried out in an inert atmosphere. Subsequent production costs are reduced; the mold body 11 , the silicon dioxide layer 12 and the barrier layer 13 in the hot bending mold 100 combine to improve the overall performance of the hot bending mold 100 , while the adjacent layers in the hot bending mold 100 There is excellent bonding force between them, which further improves the stability and service life of the overall structure.

In the related art, when hot bending the ceramic piece, the mold body 11 is directly in contact with the ceramic piece to perform the hot bending operation. Since the hot bending is performed at a high temperature, during the process, the surface of the mold body 11 reacts under the high temperature condition. Silica is generated; although the generated silica blocks the further reaction of the mold body 11, the silica will react with the ceramic pieces to produce silicates and other substances, causing bubbling on the surface of the ceramic pieces, and with the mold There is bonding between the bodies 11, which causes sticking to the mold and makes it difficult to release the mold. In the present application, by providing the barrier layer 13, the contact reaction between the ceramic piece and the mold body 11 is blocked, so that the surface quality of the ceramic piece is good, easy to demould, and the stability of the overall structure is improved. At the same time, the silica layer 12 is provided. , to improve the bonding force between the mold body 11 and the barrier layer 13 and enhance the structural stability.

In the present application, the material of the mold body 11 includes a silicon-containing compound, so that the hot bending mold 100 has excellent high temperature strength, thermal shock resistance, high temperature corrosion resistance and low creep rate, ensuring the performance of the hot bending mold 100 and service life.

Please refer to FIG. 3 , which is a schematic structural diagram of a hot bending mold according to an embodiment of the present application, wherein the mold body 11 includes a matching male mold 112 and a female mold 111 . It can be understood that the schematic diagram of the opening and closing state of the hot bending mold 100 shown in FIG. 3 , the matching male mold 112 and the female mold 111 can be covered together, and there is a capacity between the male mold 112 and the female mold 111. Therefore, the hot bending mold 100 has an accommodating cavity 10 for accommodating the ceramic piece. The punch 112 may also be referred to as a rear mold, a movable mold, a male mold, a lower mold or a male mold, and the female mold 111 may also be referred to as a front mold, a fixed mold, a female mold, an upper mold or a female mold. It can be understood that the structure of the mold body 11 in FIG. 3 is only an example, and the mold body 11 of other shapes and matching states is also applicable to the present application. It can be understood that the hot bending mold 100 has the accommodating cavity 10, that is to say, after the punch 112 and the concave mold 111 are closed, there is a gap between the convex mold 112 and the concave mold 111, so that the hot bending mold 100 has The accommodating cavity 10 , that is, the mold body 11 has an accommodating cavity space therein. In the embodiment of the present application, when the mold body 11 includes a male mold 112 and a female mold 111, since the silicon dioxide layer 12 and at least one barrier layer 13 are sequentially disposed on the side of the mold body 11 close to the accommodating cavity 10, therefore , a silicon dioxide layer 12 and at least one barrier layer 13 are sequentially arranged on the surface of the convex mold 112 on the side close to the accommodating cavity 10, and a silicon dioxide layer 12 is sequentially arranged on the surface of the concave mold 111 on the side close to the accommodating cavity 10. The silicon layer 12 and at least one barrier layer 13, that is, along the direction from the outside of the hot bending mold 100 to the accommodating cavity 10, the hot bending mold 100 includes a mold body 11, a silicon dioxide layer 12 and at least one barrier layer Layer 13. In the present application, by disposing the barrier layer 13 on the surfaces of the punch 112 and the die 111, the barrier layer 13 is in contact with the ceramic piece, so as to avoid the contact reaction between the punch 112 and the die 111 and the ceramic piece, and ensure the ceramic piece At the same time, the transition is carried out through the silicon dioxide layer 12, so that the convex mold 112, the concave mold 111, and the barrier layer 13 are more stably combined, and the stability of the overall structure is improved. In one embodiment, the male mold 112 and the female mold 111 can be fixed by plugging and clamping, or can be fixed by screws, which can be selected according to needs.

In the embodiments of the present application, the silicon-containing compound includes at least one of silicon carbide and silicon nitride. The mold body 11 made of silicon carbide and/or silicon nitride has excellent high-temperature strength and low high-temperature creep rate, which further improves the service life of the mold body 11 . In one embodiment, when the mold body 11 includes a male mold 112 and a female mold 111 , the materials of the male mold 112 and the female mold 111 respectively include at least one of silicon carbide and silicon nitride. Specifically, the materials of the punch 112 and the die 111 may be the same or different.

In the embodiment of the present application, the mold body 11 may be obtained by pressureless sintering, hot pressing sintering, hot isostatic pressing sintering, or reaction sintering. In one embodiment, after mixing silicon carbide with a binder, a green body is obtained by dry pressing, extrusion molding or injection molding, and the green body is sintered to obtain the mold body 11 . Specifically, the sintering temperature may be 1200°C-1500°C, and the sintering time may be 1h-5h. In the present application, the thickness and shape of the mold body 11 and the size of the accommodating cavity 10 can be selected according to actual needs.

Flexural strength is the ability to resist bending without breaking. Generally, three-point bending test or four-point test method are used for evaluation. In this application, the four-point bending strength test of the mold body 11 is carried out by adopting GB/T 6569-2006 "Bending Strength Test Method of Fine Ceramics". In the present application, the flexural strength of the mold body 11 is greater than 550 MPa. Further, the bending strength of the mold body 11 is greater than 600 MPa. Furthermore, the bending strength of the mold body 11 is greater than 750MPa. In one embodiment, when the mold body 11 is composed of silicon carbide, the bending strength of the mold body 11 is greater than 550 MPa, greater than 600 MPa, or greater than 620 MPa, or the like. In another embodiment, when the mold body 11 is composed of silicon nitride, the bending strength of the mold body 11 is greater than 750 MPa, greater than 800 MPa, or greater than 830 MPa, or the like. The mold body 11 of the present application has excellent bending strength, thereby ensuring its service life.

In this application, the porosity of the mold body 11 is detected by adopting GB/T 25995-2010 "Test Method for Density and Apparent Porosity of Fine Ceramics". In the embodiment of the present application, the porosity of the mold body 11 is less than 1%. That is, the density of the mold body 11 is greater than 99%. Further, the porosity of the mold body 11 is less than 0.5%. The low porosity of the mold body 11 ensures the bonding strength inside the mold body 11, which is beneficial to the improvement of the overall structural stability.

In the present application, the silicon dioxide layer 12 is used as a transition layer, which has a good bonding force with the mold body 11 and the barrier layer 13, and improves the overall stability. In the embodiment of the present application, during the preparation of the barrier layer 13 , the oxide ceramic material reacts with the non-bridging oxygen in the silicon dioxide layer to form a permanent bond, so that the gap between the silicon dioxide layer 12 and the barrier layer 13 is Has excellent adhesion. In the embodiment of the present application, the silicon dioxide layer 12 completely covers the surface of the mold body 11 , so as to facilitate the subsequent preparation of the barrier layer 13 and completely block the contact between the ceramic piece and the mold body 11 .

In the embodiment of the present application, the thickness of the silicon dioxide layer 12 is 10 nm-100 nm. By setting the silicon dioxide layer 12 with the above thickness, the silicon dioxide layer 12 can have strong bonding force with the mold body 11 and the barrier layer 13, thereby improving the overall structural stability and high temperature stability; the silicon dioxide layer The thickness of 12 is too thin, and the bonding force with the barrier layer 13 is general, which is not conducive to the long-term stable existence of the barrier layer 13; the strength of the silicon dioxide layer 12 is low, and when the silicon dioxide layer 12 is too thick, the proportion of silicon dioxide is too much , during the hot bending process, the strength of the mold surface layer structure is low, which affects the bonding force between the silicon dioxide layer 12 and the barrier layer 13 and the mold body 11, affects the overall structural stability, and even causes the barrier layer 13 to fall off. . Therefore, the bonding force between the silicon dioxide layer 12 of the above-mentioned thickness and the mold body 11 and the barrier layer 13 is excellent, and at the same time, the overall strength is not reduced, and the stability of the overall structure is improved. Further, the thickness of the silicon dioxide layer 12 is 15nm-90nm. Further, the thickness of the silicon dioxide layer 12 is 20nm-50nm. Specifically, the thickness of the silicon dioxide layer 12 may be, but not limited to, 10 nm, 25 nm, 30 nm, 40 nm, 50 nm, 60 nm, 65 nm, 70 nm, 75 nm or 85 nm.

In the embodiment of the present application, the mold body 11 can be calcined, so that the silicon-containing compound in the mold body 11 reacts with oxygen to generate silicon dioxide, and the silicon dioxide layer 12 can be obtained. The preparation method of the silicon dioxide layer 12 is simple and the operation is convenient. At the same time, since the silicon dioxide layer 12 is prepared by direct reaction on the surface of the mold body 11, the bonding force between the silicon dioxide layer 12 and the mold body 11 is very excellent. The occurrence of separation of the silicon dioxide layer 12 from the mold body 11 at high temperature is avoided. In one embodiment, the calcination temperature may be 1200°C-1500°C, and the time is 1h-5h. Further, the calcination temperature can be 1250°C-1400°C, and the time is 2h-4.5h.

In this application, the barrier layer 13 is used to block the contact between the mold body 11 and the ceramic piece, to prevent the reaction between the mold body 11 and the ceramic piece during the hot bending process, and to ensure that the ceramic piece is easy to be demolded after hot bending, and the ceramic piece can be easily demolded. The surface flatness of the part is good; at the same time, the bonding force between the barrier layer 13 and the silicon dioxide layer 12 is good, so that the barrier layer 13 can be well arranged on the mold body 11 to avoid the occurrence of falling off. In the embodiment of the present application, the barrier layer 13 completely covers the silicon dioxide layer 12 to completely isolate the contact between the ceramic piece and the silicon dioxide layer 12 and ensure the quality of the ceramic piece.

In the present application, one or more barrier layers 13 may be included in the hot bending die 100 . The above effect can be achieved by providing one layer of barrier layer 13 , and by providing multiple layers of barrier layer 13 , the stability of the overall structure of the hot bending die 100 can be further improved. In an embodiment of the present application, the number of layers of the barrier layer 13 is less than 10 layers. That is to say, one to nine layers of barrier layers 13 can be provided in the hot bending die 100 . By providing the above-mentioned barrier layer 13, the stability of the overall structure is ensured, and the internal stress accumulated in the barrier layer 13 during the hot bending process will not be too large, preventing the occurrence of peeling. Further, the number of layers of the barrier layer 13 is 2 to 8 layers. Specifically, the hot bending mold 100 may include, but is not limited to, 1 barrier layer 13 , 2 barrier layers 13 , 3 barrier layers 13 , 4 barrier layers 13 , 5 barrier layers 13 , 6 barrier layers 13 , 7 layers Layer barrier layer 13 , 8 layer barrier layer 13 or 9 layer barrier layer 13 . Please refer to FIG. 4 , which is a schematic structural diagram of a hot bending mold according to another embodiment of the present application, which is substantially the same as FIG. 2 , except that the hot bending mold 100 includes two barrier layers 13 . It can be understood that other numbers of multilayer barrier layers 13 may also be included in the hot bending die 100 , which will not be exemplified here. When the hot bending die 100 has the multi-layer barrier layers 13, the materials and thicknesses of the multi-layer barrier layers 13 may be the same or different, and may be selected according to needs.

In the embodiment of the present application, the thickness of the barrier layer 13 is 100 nm-500 nm. It can be understood that the thickness of the barrier layer 13 here is the thickness of one barrier layer 13 . By providing the barrier layer 13 with the above thickness, it can not only prevent the ceramic piece from contacting and reacting with the mold body 11 , but also has excellent bonding force with the silicon dioxide layer 12 , and also ensures that when there are multiple barrier layers 13 , the The barrier layers 13 can be better combined to prevent peeling. Further, the thickness of the barrier layer 13 is 100 nm-450 nm. Further, the thickness of the barrier layer 13 is 100nm-200nm. Specifically, the thickness of the blocking layer 13 may be, but not limited to, 120 nm, 160 nm, 170 nm, 190 nm, 230 nm, 250 nm, 280 nm, 300 nm, 340 nm, 370 nm, 400 nm, 440 nm, 450 nm or 480 nm.

In the embodiment of the present application, when the hot bending die 100 has multiple barrier layers 13 , the total thickness of the barrier layers 13 is less than 990 nm. It not only ensures the bonding force with silica, but also acts as a barrier. Further, the total thickness of the barrier layer 13 is less than 800 nm. Furthermore, the total thickness of the barrier layer 13 is less than 500 nm. In one embodiment, when the hot bending mold 100 has the multi-layer barrier layer 13 , the thickness of the multi-layer barrier layer 13 increases along the direction from the silicon dioxide layer 12 to the accommodating cavity 10 . Therefore, the barrier layer 13 close to the silicon dioxide layer 12 mainly plays a bonding role to ensure the bonding force with the silicon dioxide layer 12, and the barrier layer 13 near the accommodating cavity 10 mainly plays a blocking role, blocking the ceramic piece and the mold body. 11 is in contact with the silicon dioxide layer 12 . In one embodiment, when the hot bending mold 100 has multiple barrier layers 13, it includes a first barrier layer, a second barrier layer, ..., an Nth barrier layer, which are sequentially arranged on the silicon dioxide 12, wherein N is positive Integer. Optionally, N is a positive integer less than 10. In a specific embodiment, the thickness of the first barrier layer is 50nm-150nm, 80nm-120nm or 100nm-150nm, so as to first ensure the bonding force between the multi-layer barrier layer and the silicon dioxide layer and ensure the stability of the overall structure . In another specific embodiment, the thickness of the Nth barrier layer is 160nm-500nm, 170nm-400nm, 180nm-300nm, or 180nm-200nm, so as to ensure the blocking effect of the barrier layer 13 and prevent the ceramic piece from interfering with the two during the hot bending process. The silicon oxide layer 12 is in contact with the mold body 11 .

In the present application, the material of the barrier layer 13 includes oxide ceramic material, so that the barrier layer 13 has stable performance, is not easily oxidized with oxygen, and has high stability of the layer structure, which is conducive to the direct use of the hot bending mold 100 in an air atmosphere without the need for The use of an inert atmosphere reduces the technological difficulty of subsequent applications; at the same time, the material of the barrier layer 13 does not contain silicon dioxide, which can avoid the reaction between the ceramic piece and the silicon dioxide during the hot bending process, and avoid the problem of difficulty in demolding. Oxide ceramic materials have excellent strength, hardness, insulation, heat conduction, high temperature resistance, oxidation resistance, corrosion resistance, wear resistance and high temperature strength, and have good high temperature stability and mechanical properties under harsh environmental conditions. In the embodiment of the present application, the material of the barrier layer 13 includes at least one of a binary oxide, a glass ceramic material, a titanate ceramic material, and a hydroxyapatite ceramic material. It can be understood that the material of the barrier layer 13 selected in this application does not react with the ceramic piece during the hot bending process, and at the same time has a good bonding force with silicon dioxide; specifically, the binary oxide ceramic material includes At least one of aluminum oxide, titanium oxide, zinc oxide and rare earth oxide. Further, the oxide ceramic material includes at least one of alumina, titania, yttrium oxide and cerium oxide. In an embodiment of the present application, the material of the barrier layer 13 is aluminum oxide. The aluminum oxide and the silicon dioxide layer can generate strong chemical bonds, thereby improving the bonding force between the barrier layer and the silicon dioxide layer. In another embodiment of the present application, the material of the barrier layer 13 includes aluminum oxide, and at least one of titanium dioxide, yttrium oxide, and cerium oxide. By adding at least one of titanium dioxide, yttrium oxide, and cerium oxide, the performance of the barrier layer 13 can be improved. In one embodiment, the barrier layer 13 includes 80%-100% of aluminum oxide, 0%-20% of titanium dioxide, 0%-5% of yttrium oxide, and 0%-1% of cerium oxide by mass percentage. Among them, titanium oxide can improve the density and hardness of the barrier layer 13, so that the barrier layer 13 is not easy to wear during recycling; yttrium oxide and cerium oxide can improve the density of the barrier layer 13 and the bonding force between the multilayer barrier layers 13 , it is not easy to peel off during recycling, and it also improves the overall thermal shock resistance. Further, the mass content of aluminum oxide in the barrier layer 13 is 85%-98%, 85%-96%, 88%-95%, or 90%-95%. Specifically, the mass content of aluminum oxide in the barrier layer 13 may be, but not limited to, 80%, 82%, 84%, 86%, 89%, 91%, 92%, 93%, 94%, 97% or 99%. Further, the mass content of titanium dioxide in the barrier layer 13 is 1%-15%, 2%-13%, 3%-10%, or 3%-8%. Specifically, the mass content of titanium dioxide in the barrier layer 13 may be, but not limited to, 4%, 5%, 6%, 11%, 12%, 16%, 18% or 19%. Further, the mass content of yttrium oxide in the barrier layer 13 is 1%-5%, 1%-4%, 1%-3%, or 2%-5%. Specifically, the mass content of yttrium oxide in the barrier layer 13 may be, but not limited to, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4.5% or 5%. Further, the mass content of cerium oxide in the barrier layer 13 is 0%-0.8%, 0%-0.01%, 0.001%-0.5%, or 0.001%-0.1%. Specifically, the mass content of cerium oxide in the barrier layer 13 may be, but not limited to, 0.001%, 0.005%, 0.008%, 0.01%, 0.05%, 0.07%, 0.1%, 0.3%, 0.5% or 0.7%. In another embodiment, the barrier layer 13 includes aluminum oxide 90%-95%, titanium dioxide 3%-8%, yttrium oxide 1%-3%, and cerium oxide 0%-0.01% in mass percentage. In yet another embodiment, the barrier layer 13 includes 90%-95% of aluminum oxide, 3%-8% of titanium dioxide, 1%-3% of yttrium oxide, and 0.001%-0.01% of cerium oxide by mass percentage. Since cerium oxide is light yellow, cerium oxide in the above range can avoid changing the surface color of the ceramic part, and at the same time try to avoid a small amount of cerium atoms infiltrating into the crystal lattice of the ceramic part during hot bending, so as to avoid the phase change strengthening of the ceramic part. Influence, to ensure the strength of the ceramic parts.

In the embodiment of the present application, the total thickness of the silicon dioxide layer 12 and at least one barrier layer 13 is below 1000 nm. That is to say, the total thickness of the coating provided on the mold body 11 is below 1000 nm, thereby ensuring that the hot bending mold 100 will not accumulate excessive internal stress in the coating during the cycle of use, preventing the coating from falling off and ensuring Stability of the overall structure of the hot bending die 100 . In one embodiment, the total thickness of the silicon dioxide layer 12 and at least one barrier layer 13 is 100 nm-1000 nm. Therefore, the thickness of the coating is not too thin, it is not easy to wear through, the service life is long, and the stability of the structure is also ensured. Further, the total thickness of the silicon dioxide layer 12 and at least one barrier layer 13 is 200 nm-1000 nm, 200 nm-900 nm, 300 nm-800 nm, and the like.

In the embodiment of the present application, the roughness of the surface of the hot bending die 100 on the side close to the accommodating cavity 10 is less than 100 nm. Thus, it is ensured that no bonding occurs between the ceramic piece and the hot bending die 100 during the hot bending process, and at the same time, the surface of the ceramic piece is guaranteed to be flat and smooth. Further, the roughness of the surface of the side of the hot bending mold 100 close to the accommodating cavity 10 is less than 50 nm, 60 nm, 70 nm, 80 nm or 90 nm.

In the embodiment of the present application, the bending strength of the hot bending die 100 is greater than 600 MPa. Further, the bending strength of the hot bending die 100 is greater than 670 MPa. Furthermore, the bending strength of the hot bending die 100 is greater than 800 MPa. In one embodiment, when the mold body 11 is composed of silicon carbide, the bending strength of the hot bending mold 100 is greater than 600 MPa. In another embodiment, when the mold body 11 is composed of silicon nitride, the bending strength of the hot bending mold 100 is greater than 800 MPa. The hot bending die 100 of the present application has excellent bending strength to ensure its service life.

In the embodiment of the present application, the porosity of the hot bending die 100 is less than 0.1%. Further, the porosity of the mold body 11 is less than 0.5%. The low porosity of the hot-bending mold 100 ensures the bonding strength inside the hot-bending mold 100, which is beneficial to the improvement of the overall structural stability.

In the present application, the silicon dioxide layer 12 and the barrier layer 13 are provided on the mold body 11, so that the hot bending mold 100 has excellent performance, stable structure and long service life; it will not stick to the ceramic parts during hot bending. junction, to ensure that the ceramic piece is easy to demould, and at the same time, it can be directly used in an air atmosphere, thereby reducing the production cost of the ceramic piece.

Please refer to FIG. 5 , which is a flowchart of a method for preparing a hot-bending mold according to an embodiment of the present application. The preparation method for preparing the hot-bending mold 100 of any of the above-mentioned embodiments includes:

Operation 101 : providing a mold body precursor, the material of the mold body precursor includes a silicon-containing compound, and the mold body precursor has a accommodating cavity.

Operation 102 : calcining the mold body precursor to form a silicon dioxide layer on the surface of the mold body precursor near the accommodating cavity.

Operation 103: At least one barrier layer is formed on the surface of the silicon dioxide layer, and the material of the barrier layer includes oxide ceramic material and does not contain silicon dioxide to obtain a hot bending mold.

In operation 101, the mold body precursor may be obtained by pressureless sintering, hot pressing sintering, hot isostatic pressing sintering, or reaction sintering, or may be a commercially available mold body precursor. In the embodiment of the present application, the porosity of the mold body precursor is less than 1%, the content of free silicon is less than 1%, and the content of free carbon is less than 1%. Thus, the performance of the hot bending die 100 is guaranteed. In the embodiment of the present application, the sintering temperature may be 1200°C-1500°C, and the time may be 1h-5h. Further, the sintering temperature is 1250°C-1400°C, and the time can be 1h-3h. Specifically, the sintering can be carried out, but not limited to, in an air atmosphere. The internal microstructure of the mold body precursor is stabilized by sintering, the content of free silicon and free carbon is reduced, the thermal shock resistance of the mold body precursor is improved, cracking is not easy, and the service life is improved. In one embodiment, polishing the sintered mold body precursor is further included. Specifically, the surface roughness of the mold body precursor after polishing is less than 1 μm. In another embodiment, the mold body precursor may be sintered multiple times to improve the stability of the internal structure. Specifically, sintering may be performed twice, 3 times, or 4 times, etc., but not limited to, and polishing treatment may be performed after each sintering.

In operation 102 , the mold body precursor is calcined, and a silicon dioxide layer 12 is formed on a surface of the mold body precursor near the accommodating cavity 10 . The mold body precursor has a silicon-containing compound, and through calcination, the silicon-containing compound is reacted with oxygen to produce silicon dioxide on the surface of the mold body precursor. It can be understood that, since the surface of the mold body precursor reacts during this process, it is different from the composition of the mold body 11 in the final hot bending mold 100. Therefore, the mold body 11 before the reaction is called as the mold body 11. It is a mold body precursor, but the relevant properties, structures, etc. of the mold body precursor can all be within the description range of the mold body 11 above. Specifically, when the mold body precursor includes a concave mold precursor and a convex mold precursor, the concave mold precursor and the convex mold precursor can be calcined on one side surface of the concave mold precursor and the convex mold precursor close to the accommodating cavity 10, so that the concave mold precursor and the convex mold precursor are calcined. The silicon dioxide layer 12 is formed on the surface of one side of the punch precursor close to the accommodating cavity 10, respectively. That is, after the calcination process, the mold body precursor becomes the mold body 11 , the concave mold precursor becomes the concave mold 111 , and the punch precursor becomes the punch 112 . In one embodiment, the calcination temperature is 1200°C-1500°C, and the time is 1h-5h. Further, the calcination temperature is 1250°C-1450°C, and the time is 1.5h-4h.

In operation 103, the barrier layer 13 may be formed by at least one of vapor deposition and spray coating. In one embodiment, the multi-layer barrier layer 13 may be formed on the surface of the silicon dioxide layer 12, and the formation method of the multi-layer barrier layer 13 may be the same or different. In another embodiment, the vapor deposition includes at least one of physical vapor deposition and chemical vapor deposition, specifically, but not limited to, vacuum evaporation, magnetron sputtering, atmospheric pressure chemical vapor deposition, etc. The bonding force between the silicon oxide layers 12 . In yet another embodiment, the spraying is thermal spraying, specifically, but not limited to, plasma thermal spraying, which reduces the complexity of the process and reduces the manufacturing cost. In one embodiment, alumina is used as the target material, and the barrier layer 13 is evaporated on the surface of the silicon dioxide layer in vacuum, wherein the target material power is 6kW-10kW, nitrogen is used as the reaction gas, and the flow rate of nitrogen is 120sccm- 150sccm, the coating time is 5min-10min. In another embodiment, the arc voltage of plasma thermal spraying is 80V-100V, the arc current is 600A-800A, the spraying distance is 500mm-90mm, the spraying moving speed is 3m/min-5m/min, and the argon gas flow is ^25dm3 . /min-40dm ³ /min, hydrogen flow 120dm ³ /min-160dm ³ /min. In a specific embodiment, the arc voltage of plasma thermal spraying is 90V, the arc current is 700A, the spraying distance is 80mm, the moving speed of the spray gun is 5m/min, the flow rate of argon is 30dm ³ /min, and the flow rate of hydrogen gas is 150dm ³ /min. .

In the embodiment of the present application, after the barrier layer 13 is formed, a calcination process is also performed. Through calcination, the bonding force between the barrier layer 13 and the silicon dioxide layer 12 can be improved, the porosity of the barrier layer 13 and the silicon dioxide layer 12 can be reduced, and the stability and service life of the overall structure can be improved. In one embodiment, the calcination temperature is 1200°C-1500°C, and the time is 1h-5h. Further, the calcination temperature is 1250°C-1450°C, and the time is 1.5h-4h. Further, the calcination temperature is 1250°C-1400°C, and the time is 2h-4h. In another embodiment, when the multilayer barrier layer 13 is formed, the calcination treatment may be performed after the multilayer barrier layer 13 is formed. In yet another embodiment, when the multilayer barrier layer 13 is formed, calcination is performed after each barrier layer 13 is formed, so that the porosity of each barrier layer 13 and the relationship with other layer structures can be improved. The bonding force between them is enhanced, which is more conducive to the improvement of the overall structural stability.

In the embodiment of the present application, polishing processing is also performed on the hot bending die 100 . It can be understood that the polishing process is performed on the surface of the side surface of the hot bending die 100 close to the accommodating cavity 10, which is beneficial to ensure the flatness and smoothness of the surface of the ceramic piece after hot bending. In one embodiment, the roughness of the surface of the hot bending mold 100 on the side close to the accommodating cavity 10 is less than 100 nm.

The preparation method provided by the present application is simple and convenient to operate, and a hot bending die 100 with stable performance can be obtained, which is favorable for hot bending treatment of ceramic parts.

The present application also provides a curved ceramic piece 200 obtained by the above-mentioned hot bending die 100 . By using the above-mentioned hot bending mold 100 , a curved ceramic piece 200 can be produced, and the curved ceramic piece 200 can be easily separated from the hot bending die 100 , the surface is smooth and the quality is good. It can be understood that the curved ceramic piece 200 is obtained by placing the ceramic piece in the hot bending die 100 and undergoing a hot bending process; the ceramic piece may be but not limited to a flat plate, and the curved ceramic piece 200 may be, but not limited to, a 2.5D ceramic piece , 3D ceramic parts, etc. The specific shape of the curved ceramic part 200 is determined according to the internal shape of the accommodating cavity 10 of the hot bending mold 100 . Please refer to FIG. 6 , which shows a curved ceramic piece provided in an embodiment of the present application. Please refer to FIG. 7 , which is an enlarged cross-sectional view of the line A-A in FIG. 6 . It can be seen that the curved ceramic piece 200 can be produced by the above-mentioned hot bending die 100 . The curved ceramic piece 200 has a smooth surface, no bubbles, and excellent product quality, which is beneficial to its application.

The present application also provides an electronic device including the above-mentioned curved ceramic piece 200 . By arranging the curved ceramic piece 200 in the electronic device, the appearance variability of the electronic device is improved, the visual effect is enhanced, and the product competitiveness is improved. It can be understood that the electronic device may be, but not limited to, a mobile phone, a tablet computer, a notebook computer, a watch, MP3, MP4, GPS navigator, digital camera, and the like. The following takes a mobile phone as an example for description. Please refer to FIG. 8 , which is a schematic structural diagram of an electronic device according to an embodiment of the present application. The electronic device includes the above-mentioned curved ceramic piece 200 . At this time, the curved ceramic piece 200 is used as a casing of an electronic device. Specifically, the curved ceramic piece 200 can be used as, but not limited to, a back cover, a middle frame, a button, etc. of an electronic device to improve the quality of the electronic device.

Example 1

A kind of preparation method of hot bending die

A silicon carbide mold body is provided, and the silicon carbide mold body has an accommodating cavity; the surface of the side of the silicon carbide mold body close to the accommodating cavity is sintered at 1300 ° C for 2 hours and then polished, and the sintering and polishing treatment are repeated twice, and then After calcination at 1400°C for 3 hours, a silicon dioxide layer is formed on the surface of the silicon carbide mold body on the side close to the accommodating cavity.

A barrier slurry is provided, wherein the barrier slurry includes 92% alumina, 5% titania, and 3% yttria. By means of plasma spraying, a barrier layer of 150 nm is formed on the silicon dioxide layer, wherein the arc voltage of the plasma spraying is 90V, the arc current is 700A, the spraying distance is 80mm, the moving speed of the spray gun is 5m/min, and the flow rate of argon gas is ^30dm3 . /min, and the hydrogen flow rate was 150 dm ³ /min. Then, after calcining at 1250° C. for 1 h, the surface of the barrier layer is polished to make the surface roughness less than 100 nm, that is, a hot bending die is obtained.

Example 2

It is substantially the same as Example 1, except that the calcination treatment is not performed after forming the barrier layer.

Example 3

It is basically the same as Example 1, except that a silicon nitride mold body is used to form three barrier layers, and calcination is performed after each barrier layer is formed.

Comparative Example 1

It is substantially the same as Example 1, except that no silicon dioxide layer is provided.

Comparative Example 2

It is substantially the same as Example 2, except that no silicon dioxide layer is provided.

Effect Example

Using Anton Paar brand MCT300 micrometer scratch tester, and N-138 diamond spherical indenter (indenter diameter 200μm, maximum load 30N), the hot bending dies prepared in the Examples and Comparative Examples were inspected. It was found that the peeling force of the barrier layer in Example 1 was 26N, the peeling force of the barrier layer in Example 2 was 17N, the peeling force of the barrier layer in Example 3 was 28N, and the peeling force of the barrier layer in Comparative Example 1 was 11N , the peeling force of the barrier layer in Comparative Example 2 was 7N. It can be seen that the bonding force of the barrier layer in the hot bending mold provided by the present application is better, and the stability of the overall structure is stronger, which is favorable for long-term use.

The content provided by the embodiments of the present application has been introduced in detail above, and the principles and embodiments of the present application have been described and explained herein. Persons of ordinary skill, according to the idea of the present application, will have changes in the specific implementation manner and application scope. In conclusion, the contents of this specification should not be construed as a limitation on the present application.

Claims (14)

1. A hot-bending mold for hot-bending a ceramic piece, characterized in that the hot-bending die has an accommodating cavity, and the accommodating cavity is used for accommodating the ceramic piece, and the hot-bending die comprises a mold body, a silicon dioxide layer and at least one barrier layer sequentially arranged on the side of the mold body close to the accommodating cavity, the material of the mold body includes a silicon-containing compound, and the material of the barrier layer includes an oxide layer Ceramic material and silica-free. 2 . The hot bending die according to claim 1 , wherein the thickness of the barrier layer is 100 nm-500 nm. 3 . 3 . The hot bending mold according to claim 1 , wherein, in the hot bending mold, the number of layers of the barrier layer is less than 10 layers. 4 . 4 . The hot bending mold according to claim 1 , wherein the thickness of the silicon dioxide layer is 10 nm-100 nm. 5 . 5. The hot bending die of claim 1, wherein the oxide ceramic material comprises at least one of alumina, titania, yttria, and cerium oxide. 6. The hot bending die according to claim 1, wherein, by mass percentage, the barrier layer comprises:

7 . The hot bending die according to claim 1 , wherein the material of the die body comprises at least one of silicon carbide and silicon nitride. 8 . 8. The hot bending die according to claim 1, wherein the surface roughness of the surface of the hot bending die close to the accommodating cavity is less than 100 nm, and the bending strength is greater than 600 MPa. The porosity is less than 0.1%. 9. a preparation method of hot bending mould, is characterized in that, comprises: providing a mold body precursor, the material of the mold body precursor includes a silicon-containing compound, and the mold body precursor has a accommodating cavity; calcining the mold body precursor to generate a silicon dioxide layer on the surface of the mold body precursor near the accommodating cavity; At least one barrier layer is formed on the surface of the silicon dioxide layer, and the material of the barrier layer includes oxide ceramic material and does not contain silicon dioxide to obtain a hot bending mold. 10 . The preparation method according to claim 9 , wherein after the barrier layer is formed, a calcination treatment is also performed. 11 . 11. The preparation method according to claim 9 or 10, wherein the calcining temperature is 1200°C-1500°C, and the time is 1h-5h. 12 . The preparation method according to claim 9 , wherein the forming at least one barrier layer comprises: forming the barrier layer by at least one of vapor deposition and spraying. 13 . 13. A curved ceramic piece, characterized in that, it is obtained by using the hot bending die according to any one of claims 1-8. 14. An electronic device, comprising the curved ceramic piece according to claim 13.

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