A composite side sealing plate and its preparation method

Abstract

This invention relates to the field of twin-roll thin strip casting and rolling technology, specifically disclosing a composite side sealing plate applied to the twin-roll thin strip casting and rolling process. The thermal conductivity, elastic modulus, and coefficient of linear expansion of the composite side sealing plate vary gradients along the thickness direction; or the thermal conductivity, elastic modulus, and coefficient of linear expansion of the composite side sealing plate vary gradients along the height direction. Therefore, when this composite side sealing plate is applied to the twin-roll thin strip casting and rolling process, it can effectively reduce the maximum thermal stress generated by the composite side sealing plate, avoid cracks or even fractures caused by the interaction between thermal stress and supporting force, and improve the service life of the composite side sealing plate.

Description

Technical Field

[0001] This invention relates to the field of twin-roll thin strip casting and rolling technology, and in particular to a composite side sealing plate and its preparation method. Background Technology

[0002] Twin-roll thin strip casting involves directly pouring high-temperature molten metal into a molten pool composed of casting rolls and side sealing plates. Through the relative rotation of the crystallizing rolls, the molten metal undergoes non-equilibrium rapid solidification into a solid metal within a very short time. As is well known, twin-roll thin strip casting has received widespread attention in recent years due to its short process, low energy consumption, low emissions, and sub-rapid solidification characteristics.

[0003] Side sealing technology is one of the most critical technologies in the twin-roll thin strip casting and rolling process. The performance of the side sealing plate material directly determines the stability and safety of the twin-roll thin strip casting and rolling process, and ultimately determines whether the twin-roll thin strip casting and rolling technology can be applied on a large scale in industrial production. Optimizing the material and structure of the side sealing plate is key to improving its performance and lifespan.

[0004] Patent CN101648260B proposes to prepare a composite side sealing plate by bonding a boron nitride-containing panel and an aluminum-silicon-based thermal insulation material substrate using a modified silicone resin adhesive; Patent CN101259517A proposes to coat the surface of the side sealing plate with a 1-2 mm composite coating to improve the service life of the side sealing plate, reduce maintenance costs, and ensure mass industrial production; Patent CN205996139U proposes a composite side sealing plate and side sealing device, wherein the composite side sealing plate includes an corrosion-resistant layer, The wear-resistant layer, heating layer, and base layer are integrated together by reinforcing blocks. CN106541092B and CN109877284A propose selecting different materials according to the functional areas of the side sealing plate, with the corrosion-resistant area being zirconia-based ceramic and the wear-resistant layer mainly being BN-ZrO2-SiC-based ceramic. CN115947610 proposes a multi-layer composite side sealing plate including a working layer, a body, an insulation layer, and an interlayer transition layer. The multi-layer composite structure is made by hot pressing and sintering after raw material proportioning. However, these side sealing plates have problems such as excessive thermal stress, uneven expansion, poor wear resistance, weak corrosion resistance, or high thermal conductivity. This is mainly because the physical performance parameters between the composite layers of the side sealing plate do not change continuously and there are gaps between the interfaces. The manufacturing process is complex and demanding, resulting in poor overall rigidity of the side sealing plate, making it difficult to serve for a long time.

[0005] The thermal conductivity, coefficient of thermal expansion, and modulus of elasticity of the side sealing plate play a crucial role in its performance. Specifically, when the side sealing plate is impacted by high-temperature flowing molten steel, different locations along its thickness and height exhibit varying temperatures, creating a temperature gradient and consequently generating thermal stress. A low thermal conductivity leads to excessive internal temperature differences, easily generating significant thermal stress. An excessively high coefficient of linear expansion makes the side sealing plate susceptible to thermal deformation and resulting in greater thermal stress and potential fracture. An excessively high modulus of elasticity makes it less prone to deformation; the greater the expansion of the side sealing plate upon heating, the greater the thermal stress. The complex interaction between the thermal stress generated by the side sealing plate and the supporting force on the back side can cause cracks to appear on the surface of the side sealing plate. After prolonged casting, this can easily lead to fracture. Furthermore, the physical properties of the side sealing plate also affect its resistance to thermal shock and molten steel corrosion, potentially causing safety accidents in severe cases. Summary of the Invention

[0006] In view of this, the present invention provides a composite side sealing plate and its preparation method. When the composite side sealing plate is applied to the twin-roll thin strip casting and rolling process, it can effectively reduce the maximum thermal stress generated by the composite side sealing plate, avoid cracks or even breakage of the composite side sealing plate due to the interaction between thermal stress and support force, and improve the service life of the composite side sealing plate.

[0007] An embodiment of the first aspect of the present invention provides a composite side sealing plate for use in a twin-roll thin strip casting and rolling process, wherein the thermal conductivity, elastic modulus and linear expansion coefficient of the composite side sealing plate vary gradient along the thickness direction; or the thermal conductivity, elastic modulus and linear expansion coefficient of the composite side sealing plate vary gradient along the height direction.

[0008] Preferably, the physical performance parameters of the composite side sealing plate change gradient from the non-working surface to the working surface with the following characteristics: thermal conductivity increases, elastic modulus decreases, and linear expansion coefficient decreases; or the physical performance parameters of the composite side sealing plate change gradient from the top to the bottom with the following characteristics: thermal conductivity increases, elastic modulus decreases, and linear expansion coefficient decreases.

[0009] Preferably, the chemical composition of the composite side sealing plate varies gradually from the non-working surface to the working surface, and by mass percentage: boron nitride decreases in the range of 70% to 20%, zirconium oxide increases in the range of 10% to 60%, alumina increases in the range of 1% to 20%, silicon carbide decreases in the range of 20% to 1%, and the remainder is additives; or the chemical composition of the composite side sealing plate varies gradually from the top to the bottom, and by mass percentage: boron nitride decreases in the range of 70% to 20%, zirconium oxide increases in the range of 10% to 60%, alumina increases in the range of 1% to 20%, silicon carbide decreases in the range of 20% to 1%, and the remainder is additives.

[0010] Preferably, the chemical composition of the composite side sealing plate varies gradually from the non-working surface to the working surface, and by mass percentage: boron nitride decreases in the range of 60% to 25%, zirconium oxide increases in the range of 20% to 50%, alumina increases in the range of 1% to 10%, silicon carbide decreases in the range of 10% to 1%, and the remainder is additives; or the chemical composition of the composite side sealing plate varies gradually from the top to the bottom, and by mass percentage: boron nitride decreases in the range of 60% to 25%, zirconium oxide increases in the range of 20% to 50%, alumina increases in the range of 1% to 10%, silicon carbide decreases in the range of 10% to 1%, and the remainder is additives.

[0011] Preferably, the additive is one, two or more of yttrium oxide, magnesium oxide, graphite, boron powder, selenocyanide and borates.

[0012] Preferably, the gradient characteristics of the chemical composition of the composite side sealing plate changing from the non-working surface to the working surface are linear or quadratic functions; or the gradient characteristics of the chemical composition of the composite side sealing plate changing from the top to the bottom are linear or quadratic functions.

[0013] Preferably, the physical performance parameters of the composite side sealing plate exhibit a gradient change from the non-working surface to the working surface, specifically characterized by: an increase in thermal conductivity within the range of 8 to 30 W / (m·K), a decrease in elastic modulus within the range of 100 to 50 GPa, and a linear expansion coefficient within the range of 7.5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 The physical properties of the composite side sealing plate decrease within a certain range; specifically, the characteristics of the gradient change in physical property parameters from top to bottom are: thermal conductivity increases in the range of 8 to 30 W / (m·K), elastic modulus decreases in the range of 100 to 50 GPa, and linear expansion coefficient decreases in the range of 7.5 x 10⁻⁶ W / (m·K). -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0014] Preferably, the physical performance parameters of the composite side sealing plate exhibit a gradient change from the non-working surface to the working surface, specifically characterized by: an increase in thermal conductivity within the range of 8 to 20 W / (m·K), a decrease in elastic modulus within the range of 80 to 50 GPa, and a linear expansion coefficient within the range of 5 x 10⁻⁶ W / (m·K). -6 Up to 2.5x10 -6 K -1 The characteristics of the physical properties of the composite side sealing plate decreasing within a certain range; or the gradient change of physical properties from top to bottom are specifically: thermal conductivity increasing within the range of 8 to 20 W / (m·K), elastic modulus decreasing within the range of 80 to 50 GPa, and linear expansion coefficient decreasing within the range of 5 x 10⁻⁶ W / (m·K). -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0015] A second aspect of the present invention provides a method for preparing a composite side sealing plate, comprising:

[0016] Step 1: Weigh boron nitride, zirconium oxide, aluminum oxide, silicon carbide, and additives, and prepare composite material powders with different mass percentages according to the chemical composition of claim 4 or 5;

[0017] Step 2: Spread the composite material powder layer by layer according to the mass percentage relationship, place it in a hot press mold, and perform hot pressing sintering under vacuum atmosphere;

[0018] Step 3: After hot pressing and sintering, slowly cool to room temperature while unloading the pressure to obtain the composite side sealing plate blank;

[0019] Step 4: Process the composite side sealing plate blank to obtain the composite side sealing plate.

[0020] Preferably, the hot pressing sintering temperature is 1500 to 1800°C, the hot pressing sintering pressure is 20 to 60 MPa, and the hot pressing sintering time is 60 to 240 min.

[0021] The beneficial effects of the technical solution provided by the embodiments of the present invention include at least the following: a composite side sealing plate applied to a twin-roll thin strip casting and rolling process, wherein the thermal conductivity, elastic modulus, and linear expansion coefficient of the composite side sealing plate vary gradient along the thickness direction; or the thermal conductivity, elastic modulus, and linear expansion coefficient of the composite side sealing plate vary gradient along the height direction. Therefore, when this composite side sealing plate is applied to the twin-roll thin strip casting and rolling process, it can effectively reduce the maximum thermal stress generated by the composite side sealing plate, avoid cracks or even fractures in the composite side sealing plate due to the interaction between thermal stress and supporting force, and improve the service life of the composite side sealing plate.

[0022] This invention employs composite powders with varying mass percentages of components laid in the thickness or height direction, followed by hot-pressing and sintering to obtain a monolithic composite side sealing plate. This reduces thermal stress generated during use, improves thermal shock resistance, and extends the service life of the side sealing plate. Compared to traditional composite side sealing plates that are formed by bonding corrosion-resistant, wear-resistant, heating, and base layers, the composite side sealing plate manufacturing process provided by this invention is simple and feasible. Its physical performance parameters change continuously, and the monolithic manufacturing process reduces the likelihood of damage or coiling due to differences in the linear expansion coefficients between layers.

[0023] 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, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0024] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. Wherein:

[0025] Figure 1 A schematic diagram of a physical model of a composite side seal with continuously gradient-varying physical performance parameters in the thickness direction, provided by an embodiment of the first type of the present invention, is shown.

[0026] Figure 2 It shows Figure 1 A schematic diagram illustrating the continuous gradient change of physical performance parameters in the thickness direction in the embodiment shown;

[0027] Figure 3 A schematic diagram of the physical model of a composite side seal with continuously gradient-varying physical performance parameters in the height direction, provided by a second type of embodiment of the present invention, is shown.

[0028] Figure 4 It shows Figure 3 A schematic diagram illustrating the continuous gradient change of physical performance parameters in the height direction in the illustrated embodiment;

[0029] Figure 5 A schematic diagram of a function model showing the continuous gradient change of the physical performance parameters of the side sealing plate in an embodiment of the present invention is shown. Detailed Implementation

[0030] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0032] The following reference Figures 1 to 5 This invention describes a composite side sealing plate and its preparation method according to some embodiments of the present invention. The working surface is the surface of the composite side sealing plate that directly contacts molten steel during use, and the non-working surface is the side of the composite side sealing plate that faces away from the working surface during use.

[0033] According to an embodiment of the first aspect of the present invention, a composite side sealing plate for use in a twin-roll thin strip casting and rolling process is provided. The thermal conductivity, elastic modulus, and coefficient of linear expansion of the composite side sealing plate vary gradient along the thickness direction; or the thermal conductivity, elastic modulus, and coefficient of linear expansion of the composite side sealing plate vary gradient along the height direction. Therefore, when this composite side sealing plate is applied to the twin-roll thin strip casting and rolling process, the maximum thermal stress generated by the composite side sealing plate can be effectively reduced, preventing cracks or even fractures caused by the interaction between thermal stress and supporting force, thus improving the service life of the composite side sealing plate.

[0034] Specifically, when the side sealing plate is impacted by high-temperature flowing molten steel, the temperature varies at different locations along its thickness and height, creating a temperature gradient that generates thermal stress. The continuous gradient change in the physical property parameters of the composite side sealing plate effectively reduces residual stress and thermal stress between adjacent interfaces, improves the bonding strength of the material, and effectively alleviates the thermal stress caused by temperature differences along the thickness or height of the composite side sealing plate, thus exhibiting excellent thermal shock resistance.

[0035] Preferably, the physical performance parameters of the composite side sealing plate change gradient from the non-working surface to the working surface with the following characteristics: thermal conductivity increases, elastic modulus decreases, and linear expansion coefficient decreases; or the physical performance parameters of the composite side sealing plate change gradient from the top to the bottom with the following characteristics: thermal conductivity increases, elastic modulus decreases, and linear expansion coefficient decreases.

[0036] Understandably, a side sealing plate with a low thermal conductivity leads to excessive internal temperature differences, easily generating significant thermal stress. Similarly, a side sealing plate with a high coefficient of linear expansion is prone to thermal stress due to thermal deformation, potentially causing breakage. Furthermore, a side sealing plate with a high elastic modulus is less prone to deformation, resulting in greater thermal stress as its volume expands upon heating. Therefore, two types of composite side sealing plates are used. The first type has physical property parameters that vary from the non-working surface to the working surface, while the second type varies from the top to the bottom. This reduces the thermal stress experienced by the composite side sealing plate in both the thickness and height directions, respectively.

[0037] Preferably, the composite side sealing plate exhibits a continuous gradient change in its physical performance parameters along its thickness or height direction, determined by the mass percentage of each component in the composite side sealing plate material. Specifically, the chemical composition of the composite side sealing plate varies gradient from the non-working surface to the working surface, with the following mass percentages: boron nitride decreases from 70% to 20%, zirconium oxide increases from 10% to 60%, alumina increases from 1% to 20%, silicon carbide decreases from 20% to 1%, and the remainder is additives; or the chemical composition of the composite side sealing plate varies gradient from the top to the bottom, with the following mass percentages: boron nitride decreases from 70% to 20%, zirconium oxide increases from 10% to 60%, alumina increases from 1% to 20%, silicon carbide decreases from 20% to 1%, and the remainder is additives. This material gives the composite side sealing plate excellent thermal shock resistance and resistance to molten steel corrosion. By adjusting the mass percentage of each chemical component, the thermal conductivity, elastic modulus, and coefficient of linear expansion of the composite side sealing plate can be continuously varied gradient.

[0038] Preferably, the chemical composition of the composite side sealing plate varies gradually from the non-working surface to the working surface, with the following mass percentages: boron nitride decreases from 60% to 25%, zirconium oxide increases from 20% to 50%, alumina increases from 1% to 10%, silicon carbide decreases from 10% to 1%, and the remainder is additives; or the chemical composition of the composite side sealing plate varies gradually from the top to the bottom, with the following mass percentages: boron nitride decreases from 60% to 25%, zirconium oxide increases from 20% to 50%, alumina increases from 1% to 10%, silicon carbide decreases from 10% to 1%, and the remainder is additives. In this case, the physical properties of the composite side sealing plate are optimal.

[0039] Preferably, the additive is one, two or more of yttrium oxide, magnesium oxide, graphite, boron powder, sialon (β-sialon, α-sialon, O-sialon) and borates.

[0040] Preferably, the gradient characteristics of the chemical composition of the composite side sealing plate changing from the non-working surface to the working surface are linear or quadratic functions; or the gradient characteristics of the chemical composition of the composite side sealing plate changing from the top to the bottom are linear or quadratic functions.

[0041] Specifically, when the gradient characteristic of the chemical composition of the composite side sealing plate changing from the non-working surface to the working surface is a linear function, the gradient characteristic of the physical performance parameters of the composite side sealing plate changing from the non-working surface to the working surface is approximately a linear function. Similarly, when the gradient characteristic of the chemical composition of the composite side sealing plate changing from the non-working surface to the working surface is a quadratic function, the gradient characteristic of the physical performance parameters of the composite side sealing plate changing from the non-working surface to the working surface is approximately a quadratic function; when the gradient characteristic of the chemical composition of the composite side sealing plate changing from the top to the bottom is a linear function, the gradient characteristic of the physical performance parameters of the composite side sealing plate changing from the top to the bottom is approximately a linear function; when the gradient characteristic of the chemical composition of the composite side sealing plate changing from the top to the bottom is a quadratic function, the gradient characteristic of the physical performance parameters of the composite side sealing plate changing from the top to the bottom is approximately a quadratic function.

[0042] Based on the above characteristics, the composite side sealing plate can effectively reduce the maximum thermal stress generated in the actual application of the twin-roll thin strip casting process, avoid cracks or even breakage of the composite side sealing plate due to the complex interaction between thermal stress and support force, and improve the service life of the composite side sealing plate.

[0043] Preferably, the physical performance parameters of the composite side sealing plate exhibit a gradient change from the non-working surface to the working surface, specifically characterized by: an increase in thermal conductivity within the range of 8 to 30 W / (m·K), a decrease in elastic modulus within the range of 100 to 50 GPa, and a linear expansion coefficient within the range of 7.5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 The physical properties of the composite side sealing plate decrease within a certain range; specifically, the characteristics of the gradient change in physical property parameters from top to bottom are: thermal conductivity increases in the range of 8 to 30 W / (m·K), elastic modulus decreases in the range of 100 to 50 GPa, and linear expansion coefficient decreases in the range of 7.5 x 10⁻⁶ W / (m·K). -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0044] Preferably, the physical performance parameters of the composite side sealing plate exhibit a gradient change from the non-working surface to the working surface, specifically characterized by: an increase in thermal conductivity within the range of 8 to 20 W / (m·K), a decrease in elastic modulus within the range of 80 to 50 GPa, and a linear expansion coefficient within the range of 5 x 10⁻⁶ W / (m·K). -6 Up to 2.5x10 -6 K -1 The characteristics of the physical properties of the composite side sealing plate decreasing within a certain range; or the gradient change of physical properties from top to bottom are specifically: thermal conductivity increasing within the range of 8 to 20 W / (m·K), elastic modulus decreasing within the range of 80 to 50 GPa, and linear expansion coefficient decreasing within the range of 5 x 10⁻⁶ W / (m·K). -6 Up to 2.5x10 -6 K-1 Decrease within the range.

[0045] A method for preparing a composite side sealing plate according to an embodiment of a second aspect of the present invention includes:

[0046] Step 1: Weigh boron nitride, zirconium oxide, aluminum oxide, silicon carbide, and additives, and prepare composite material powders with different mass percentages according to the chemical composition of claim 4 or 5;

[0047] Step 2: Spread the composite material powder layer by layer according to the mass percentage relationship, place it in a hot press mold, and perform hot pressing sintering under vacuum atmosphere;

[0048] Specifically, composite material powders with different mass percentages can be prepared sequentially by mechanical equipment according to a pre-set ratio, and the powder can be automatically spread to achieve a continuous gradient change in chemical composition, thereby achieving a continuous change in the physical performance parameters of the side sealing plate.

[0049] Step 3: After hot pressing and sintering, slowly cool to room temperature while unloading the pressure to obtain the composite side sealing plate blank;

[0050] Step 4: Process the composite side sealing plate blank to obtain the composite side sealing plate.

[0051] Preferably, the hot pressing sintering temperature is 1500 to 1800°C, the hot pressing sintering pressure is 20 to 60 MPa, and the hot pressing sintering time is 60 to 240 min.

[0052] The following application examples further illustrate the composite side sealing plate provided in this application.

[0053] Example 1:

[0054] A composite side sealing plate with gradient changes in physical performance parameters along the thickness direction.

[0055] like Figures 1 to 2 As shown, Figure 1 A schematic diagram of the physical model of a composite side sealing plate with continuously varying physical performance parameters from the non-working surface to the working surface; Figure 2 This describes the continuous gradient change of physical property parameters from the non-working surface to the working surface. From the non-working surface to the working surface of the side sealing plate, the thermal conductivity λ1 increases, the elastic modulus E1 decreases, and the coefficient of linear expansion α1 decreases. Specifically, from the non-working surface to the working surface of the side sealing plate, the mass of boron nitride powder decreases linearly from 70% to 20%, the mass of zirconium oxide powder increases linearly from 10% to 60%, the mass of alumina powder increases linearly from 1% to 10%, the mass of silicon carbide powder decreases linearly from 10% to 1%, and the remainder is additives.

[0056] Furthermore, the linear functional relationship followed by the mass change of boron nitride powder is: M BN(1) = -50h1 + 70; where h is the non-working surface. 1(0) =0; the side sealing plate has an arbitrary distance of h in the thickness direction. x1 The distance from the non-working surface to the working surface is the total thickness h of the side sealing plate. t1 The side sealing plate thickness ratio is H1 = h x1 / h t1 The value is between 0 and 1; M represents the mass percentage of each component. The linear functional relationship that the mass change of zirconium oxide powder follows is: M ZrO2(1) =50h1+10; The linear functional relationship followed by the mass change of alumina powder is: M Al2O3(1) =9h1+1; The linear functional relationship followed by the mass change of silicon carbide powder is: M SiC(1) =-9h1+10, the rest are additives.

[0057] Further, the composite material powder is laid layer by layer according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering; the hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 20 to 60 MPa, sintering temperature of 1500 to 1800℃, and sintering time of 60 to 240 min; after hot pressing sintering, it is slowly cooled to room temperature and the pressure is unloaded to obtain a composite side sealing plate blank; the side sealing plate blank is processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0058] Among them, from the non-working surface to the working surface of the side sealing plate, the thermal conductivity increases in the range of 8 to 20 W / (m·K), the elastic modulus decreases in the range of 80 to 50 GPa, and the coefficient of linear expansion is 5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0059] Example 2:

[0060] A composite side sealing plate with gradient changes in physical performance parameters along the height direction.

[0061] like Figures 3 to 4 As shown, Figure 3 A schematic diagram of the physical model of a composite side seal plate with continuously varying physical performance parameters from top to bottom; Figure 4This illustrates the continuous gradient change of physical property parameters from top to bottom. From the top to the bottom of the side sealing plate, the thermal conductivity λ2 increases, the elastic modulus E2 decreases, and the coefficient of linear expansion α2 decreases. Specifically, from the top to the bottom of the side sealing plate, the mass of boron nitride powder decreases linearly from 70% to 20%, the mass of zirconium oxide powder increases linearly from 10% to 60%, the mass of alumina powder increases linearly from 1% to 10%, the mass of silicon carbide powder decreases linearly from 10% to 1%, and the remainder is additives.

[0062] Furthermore, the linear functional relationship followed by the mass change of boron nitride powder is: M BN(2) = -50x1 + 70; where, x is the top of the side panel. 1(0) =0; any distance x in the height direction of the side sealing plate x1 The distance from top to bottom is the total height of the side panel x t1 The side sealing plate thickness ratio is X1 = x x1 / x t1 The value is between 0 and 1; M represents the mass percentage of each component. The linear functional relationship that the mass change of zirconium oxide powder follows is: M ZrO2(2) =50x1+10; The linear functional relationship followed by the mass change of alumina powder is: M Al2O3(2) =9x1+1; The linear functional relationship followed by the mass change of silicon carbide powder is: M SiC(2) = -9x1+10, the rest are additives.

[0063] Further, the composite material powder is layered according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering. The hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 20 to 60 MPa, sintering temperature of 1500 to 1800 °C, and sintering time of 60 to 240 min. After hot pressing sintering, the material is slowly cooled to room temperature while the pressure is unloaded to obtain a composite side sealing plate blank. The sintered side sealing plate blank is then processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0064] Among them, from the top to the bottom of the side sealing plate, the thermal conductivity increases in the range of 8 to 20 W / (m·K), the elastic modulus decreases in the range of 80 to 50 GPa, and the coefficient of linear expansion is 5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0065] Example 3:

[0066] A composite side sealing plate with gradient changes in physical performance parameters along the thickness direction.

[0067] like Figures 1 to 2As shown, from the non-working surface to the working surface of the side sealing plate, the thermal conductivity λ3 increases, the elastic modulus E3 decreases, and the coefficient of linear expansion α3 decreases. Specifically, from the non-working surface to the working surface of the side sealing plate, the mass of boron nitride powder decreases from 70% to 20% according to a quadratic function, the mass of zirconium oxide powder increases from 10% to 60% according to a quadratic function, the mass of alumina powder increases from 1% to 10% according to a quadratic function, the mass of silicon carbide powder decreases from 10% to 1% according to a quadratic function, and the remainder is additives.

[0068] Furthermore, the mass change of boron nitride powder follows a quadratic function relationship: M BN(3) =-50h3 2 +70; where the non-working surface h 3(0) =0; the side sealing plate has an arbitrary distance of h in the thickness direction. x3 The distance from the non-working surface to the working surface is the total thickness h of the side sealing plate. t3 The side sealing plate thickness ratio is H2 = h x3 / h t3 The value is between 0 and 1; M represents the mass percentage of each component. The mass change of zirconia powder follows a quadratic function relationship: M ZrO2(3) =50h3 2 +10; The mass change of alumina powder follows a quadratic function relationship: M Al2O3(3) =9h3 2 +1; The mass change of silicon carbide powder follows a quadratic function relationship: M SiC(3) =-9h3 2 +10, the rest are additives.

[0069] Further, the composite material powder is layered according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering. The hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 20 to 60 MPa, sintering temperature of 1500 to 1800 °C, and sintering time of 60 to 240 min. After hot pressing sintering, the material is slowly cooled to room temperature while the pressure is unloaded to obtain a composite side sealing plate blank. The sintered side sealing plate blank is then processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0070] Among them, from the non-working surface to the working surface of the side sealing plate, the thermal conductivity increases in the range of 8 to 20 W / (m·K), the elastic modulus decreases in the range of 80 to 50 GPa, and the coefficient of linear expansion is 5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0071] Example 4:

[0072] A composite side sealing plate with continuously gradient changes in physical performance parameters along the height direction.

[0073] like Figures 3 to 4 As shown, from the top to the bottom of the side sealing plate, the thermal conductivity λ4 increases, the elastic modulus E4 decreases, and the coefficient of linear expansion α4 decreases. Specifically, from the top to the bottom of the side sealing plate, the mass of boron nitride powder decreases from 70% to 20% according to a quadratic function, the mass of zirconium oxide powder increases from 10% to 60% according to a quadratic function, the mass of alumina powder increases from 1% to 10% according to a quadratic function, the mass of silicon carbide powder decreases from 10% to 1% according to a quadratic function, and the remainder is additives.

[0074] Furthermore, the mass change of boron nitride powder follows a quadratic function relationship: M BN(4) =-50x4 2 +70; where the top of the side panel is x 4(0) =0; any distance x in the height direction of the side sealing plate x4 The distance from top to bottom is the total height of the side panel x t4 The side panel thickness ratio is X2 = x x4 / x t4 The value is between 0 and 1; M represents the mass percentage of each component. The mass change of zirconia powder follows a quadratic function relationship: M ZrO2(4) =50x4 2 +10; The mass change of alumina powder follows a quadratic function relationship: M Al2O3(4) =9x4 2 +1; The mass change of silicon carbide powder follows a quadratic function relationship: M SiC(4) =-9x4 2 +10, the rest are additives.

[0075] Further, the composite material powder is layered according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering. The hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 20 to 60 MPa, sintering temperature of 1500 to 1800 °C, and sintering time of 60 to 240 min. After hot pressing sintering, the material is slowly cooled to room temperature while the pressure is unloaded to obtain a composite side sealing plate blank. The sintered side sealing plate blank is then processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0076] Among them, from the top to the bottom of the side sealing plate, the thermal conductivity increases in the range of 8 to 20 W / (m·K), the elastic modulus decreases in the range of 80 to 50 GPa, and the coefficient of linear expansion is 5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0077] Example 5:

[0078] A composite side sealing plate with gradient changes in physical performance parameters along the thickness direction.

[0079] like Figures 1 to 2 As shown, from the non-working surface to the working surface of the side sealing plate, the mass of boron nitride powder decreases linearly from 50% to 20%, the mass of zirconium oxide powder increases linearly from 20% to 50%, the mass of alumina powder increases linearly from 1% to 20%, the mass of silicon carbide powder decreases linearly from 20% to 1%, and the remainder is additives.

[0080] Furthermore, the linear functional relationship followed by the mass change of boron nitride powder is: M BN(5) = -30h5 + 50; where h is the non-working surface. 5(0) =0; the side sealing plate has an arbitrary distance of h in the thickness direction. x5 The distance from the non-working surface to the working surface is the total thickness h of the side sealing plate. t5 The side sealing plate thickness ratio is H3 = h x5 / h t5 The value is between 0 and 1; M represents the mass percentage of each component. The linear functional relationship that the mass change of zirconium oxide powder follows is: M ZrO2(5) =30h5+20; The linear functional relationship followed by the mass change of alumina powder is: M Al2O3(5) =19h5+1; The linear functional relationship followed by the mass change of silicon carbide powder is: M SiC(5) =-19h5+20, the rest are additives.

[0081] Further, the composite material powder is layered sequentially according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering. The hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 5 to 40 MPa, sintering temperature of 1500 to 1700 °C, and sintering time of 120 to 240 min. After hot pressing sintering, the material is slowly cooled to room temperature while the pressure is unloaded to obtain a composite side sealing plate blank. The sintered side sealing plate blank is then processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0082] Among them, from the non-working surface to the working surface of the side sealing plate, the thermal conductivity increases in the range of 8 to 16 W / (m·K), the elastic modulus decreases in the range of 100 to 60 GPa, and the coefficient of linear expansion is 7.5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0083] Example 6:

[0084] A composite side sealing plate with gradient changes in physical performance parameters along the thickness direction.

[0085] like Figures 1 to 2 As shown, from the non-working surface to the working surface of the side sealing plate, the mass of boron nitride powder decreases from 50% to 20% according to a quadratic function, the mass of zirconium oxide powder increases from 20% to 50% according to a quadratic function, the mass of alumina powder increases from 1% to 20% according to a quadratic function, the mass of silicon carbide powder decreases from 20% to 1% according to a quadratic function, and the remainder is additives.

[0086] Furthermore, the mass change of boron nitride powder follows a quadratic function relationship: M BN(6) =-30h6 2 +50; where the non-working surface h 6(0) =0; the side sealing plate has an arbitrary distance of h in the thickness direction. x6 The distance from the non-working surface to the working surface is the total thickness h of the side sealing plate. t6 The side sealing plate thickness ratio is H4 = h x6 / h t6 The value is between 0 and 1; M represents the mass percentage of each component. The mass change of zirconia powder follows a quadratic function relationship: M ZrO2(6) =30h6 2 +20; The mass change of alumina powder follows a quadratic function relationship: M Al2O3(6) =19h6 2 +1; The mass change of silicon carbide powder follows a quadratic function relationship: M SiC(6) =-19h6 2 +20, the rest are additives.

[0087] Further, the composite material powder is layered sequentially according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering. The hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 5 to 40 MPa, sintering temperature of 1500 to 1700 °C, and sintering time of 120 to 240 min. After hot pressing sintering, the material is slowly cooled to room temperature while the pressure is unloaded to obtain a composite side sealing plate blank. The sintered side sealing plate blank is then processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0088] Among them, from the non-working surface to the working surface of the side sealing plate, the thermal conductivity increases in the range of 8 to 16 W / (m·K), the elastic modulus decreases in the range of 100 to 60 GPa, and the coefficient of linear expansion is 7.5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0089] Example 7:

[0090] A composite side sealing plate with gradient changes in physical performance parameters along the thickness direction.

[0091] like Figures 1 to 2 As shown, from the non-working surface to the working surface of the side sealing plate, the mass of boron nitride powder decreases linearly from 60% to 30%, the mass of zirconium oxide powder increases linearly from 20% to 50%, the mass of alumina powder increases linearly from 1% to 10%, the mass of silicon carbide powder decreases linearly from 10% to 1%, and the remainder is additives.

[0092] Furthermore, the linear functional relationship followed by the mass change of boron nitride powder is: M BN(7) = -30h7 + 60; where h is the non-working surface. 7(0) =0; the side sealing plate has an arbitrary distance of h in the thickness direction. x7 The distance from the non-working surface to the working surface is the total thickness h of the side sealing plate. t7 The side sealing plate thickness ratio is H5 = h x7 / h t7 The value is between 0 and 1; M represents the mass percentage of each component. The linear functional relationship that the mass change of zirconium oxide powder follows is: M ZrO2(7) =30h7+20; The linear functional relationship followed by the mass change of alumina powder is: M Al2O3(7) =9h7+1; The linear functional relationship followed by the mass change of silicon carbide powder is: M SiC(7) =-9h7+10, the rest are additives.

[0093] Further, the composite material powder is layered according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering. The hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 20 to 60 MPa, sintering temperature of 1500 to 1800 °C, and sintering time of 60 to 240 min. After hot pressing sintering, the material is slowly cooled to room temperature while the pressure is unloaded to obtain a composite side sealing plate blank. The sintered side sealing plate blank is then processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0094] Among them, from the non-working surface to the working surface of the side sealing plate, the thermal conductivity increases in the range of 10 to 18 W / (m·K), the elastic modulus decreases in the range of 90 to 60 GPa, and the coefficient of linear expansion is 5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0095] Example 8:

[0096] A composite side sealing plate with gradient changes in physical performance parameters along the thickness direction.

[0097] like Figures 1 to 2 As shown, from the non-working surface to the working surface of the side sealing plate, the mass of boron nitride powder decreases linearly from 70% to 40%, the mass of zirconium oxide powder increases linearly from 10% to 40%, the mass of alumina powder increases linearly from 1% to 10%, the mass of silicon carbide powder decreases linearly from 10% to 1%, and the remainder is additives.

[0098] Furthermore, the linear functional relationship followed by the mass change of boron nitride powder is: M BN(8) = -30h8 + 70; where h is the non-working surface 8(0) =0; the side sealing plate has an arbitrary distance of h in the thickness direction. x8 The distance from the non-working surface to the working surface is the total thickness h of the side sealing plate. t8 The side sealing plate thickness ratio is H6 = h x8 / h t8 The value is between 0 and 1; M represents the mass percentage of each component. The linear functional relationship that the mass change of zirconium oxide powder follows is: M ZrO2(8) =30h8+10; The linear functional relationship followed by the mass change of alumina powder is: M Al2O3(8) =9h8+1; The linear functional relationship followed by the mass change of silicon carbide powder is: M SiC(8) =-9h8+10, the rest are additives.

[0099] Further, the composite material powder is layered sequentially according to the mass percentage relationship and placed in a hot press mold for hot pressing sintering. The hot pressing sintering conditions are: vacuum atmosphere, sintering pressure of 40 to 100 MPa, sintering temperature of 1700 to 2000 °C, and sintering time of 60 to 120 min. After hot pressing sintering, the material is slowly cooled to room temperature while the pressure is unloaded to obtain a composite side sealing plate blank. The sintered side sealing plate blank is then processed by a machine tool to obtain a composite side sealing plate with continuously gradient changes in physical property parameters in the thickness direction.

[0100] Among them, from the non-working surface to the working surface of the side sealing plate, the thermal conductivity increases in the range of 15 to 30 W / (m·K), the elastic modulus decreases in the range of 80 to 50 GPa, and the coefficient of linear expansion is 5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

[0101] The physical performance parameters of the composite side sealing plates of Examples 1 to 8 and the traditional side sealing plates are compared in the table below:

[0102] Table 1. Comparison of Physical Performance Parameters between Composite Side Sealing Panels and Traditional Side Sealing Panels

[0103]

[0104]

[0105] Among these, the thermal conductivity, coefficient of thermal expansion, and modulus of elasticity of the side sealing plate play a crucial role in its performance. In practical applications, when the side sealing plate is impacted by high-temperature flowing molten steel, the temperature varies at different locations along its thickness and height, creating a temperature gradient and consequently generating thermal stress. Data from Examples 1 to 8 show that the composite side sealing plate provided in this application, by achieving a continuous gradient change in its physical performance parameters, can effectively reduce the maximum thermal stress generated by the composite side sealing plate, preventing cracks or even breakage due to the interaction between thermal stress and supporting force, thus improving the service life of the composite side sealing plate.

[0106] In the description of this invention, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this invention, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0107] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite side sealing plate, applied in a twin-roll thin strip casting and rolling process, characterized in that: The thermal conductivity, elastic modulus, and coefficient of linear expansion of the composite side sealing plate vary gradient along the thickness direction; or The thermal conductivity, elastic modulus, and coefficient of linear expansion of the composite side sealing plate vary gradient along the height direction. The chemical composition of the composite side sealing plate varies gradient from the non-working surface to the working surface, and by mass percentage: boron nitride decreases from 70% to 20%, zirconium oxide increases from 10% to 60%, alumina increases from 1% to 20%, silicon carbide decreases from 20% to 1%, and the remainder is additives; or The chemical composition of the composite side sealing plate varies from top to bottom in a gradient, and by mass percentage: boron nitride decreases from 70% to 20%, zirconium oxide increases from 10% to 60%, aluminum oxide increases from 1% to 20%, silicon carbide decreases from 20% to 1%, and the remainder is additives.

2. The composite side sealing plate according to claim 1, characterized in that: The physical performance parameters of the composite side sealing plate exhibit a gradient change from the non-working surface to the working surface, characterized by: increased thermal conductivity, decreased elastic modulus, and decreased coefficient of linear expansion; or The physical performance parameters of the composite side sealing plate change in a gradient from top to bottom as follows: thermal conductivity increases, elastic modulus decreases, and coefficient of linear expansion decreases.

3. A composite side sealing plate according to claim 1, characterized in that: The chemical composition of the composite side sealing plate varies gradient from the non-working surface to the working surface, and by mass percentage: boron nitride decreases from 60% to 25%, zirconium oxide increases from 20% to 50%, alumina increases from 1% to 10%, silicon carbide decreases from 10% to 1%, and the remainder is additives; or The chemical composition of the composite side sealing plate varies from top to bottom in a gradient, and by mass percentage: boron nitride decreases in the range of 60% to 25%, zirconium oxide increases in the range of 20% to 50%, aluminum oxide increases in the range of 1% to 10%, silicon carbide decreases in the range of 10% to 1%, and the remainder is additives.

4. A composite side sealing plate according to claim 1, characterized in that: The additive is one, two, or more of yttrium oxide, magnesium oxide, graphite, boron powder, silon, and borate.

5. A composite side sealing plate according to claim 1, characterized in that: The gradient characteristic of the chemical composition of the composite side sealing plate changing along the non-working surface to the working surface is a linear or quadratic function; or The chemical composition of the composite side sealing plate varies from top to bottom in a gradient characteristic that is either a linear or quadratic function.

6. A composite side sealing plate according to claim 1, characterized in that: The physical performance parameters of the composite side sealing plate exhibit a gradient change from the non-working surface to the working surface, specifically characterized by: increasing thermal conductivity in the range of 8 to 30 W / (m·K), decreasing elastic modulus in the range of 100 to 50 GPa, and a linear expansion coefficient of 7.5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Reduce within the range; or The physical performance parameters of the composite side sealing plate exhibit a gradient change from top to bottom, specifically: the thermal conductivity increases in the range of 8 to 30 W / (m·K), the elastic modulus decreases in the range of 100 to 50 GPa, and the coefficient of linear expansion is 7.5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

7. A composite side sealing plate according to claim 6, characterized in that: The physical performance parameters of the composite side sealing plate exhibit a gradient change from the non-working surface to the working surface, specifically as follows: the thermal conductivity increases in the range of 8 to 20 W / (m·K), the elastic modulus decreases in the range of 80 to 50 GPa, and the coefficient of linear expansion decreases in the range of 5 x 10⁻⁶ W / (m·K). -6 Up to 2.5x10 -6 K -1 Reduce within the range; or The physical performance parameters of the composite side sealing plate exhibit a gradient change from top to bottom, specifically: the thermal conductivity increases in the range of 8 to 20 W / (m·K), the elastic modulus decreases in the range of 80 to 50 GPa, and the coefficient of linear expansion decreases in the range of 5 x 10⁻⁶. -6 Up to 2.5x10 -6 K -1 Decrease within the range.

8. The method for preparing a composite side sealing plate according to claim 1, characterized in that, include: Step 1: Weigh boron nitride, zirconium oxide, aluminum oxide, silicon carbide, and additives, and prepare composite material powders with different mass percentages according to the chemical composition described in claim 4; Step 2: The composite material powder is layered according to the mass percentage relationship and placed in a hot press mold for hot pressing and sintering under vacuum. Step 3: After hot pressing and sintering, slowly cool to room temperature while unloading the pressure to obtain the composite side sealing plate blank; Step 4: Process the composite side sealing plate blank to obtain the composite side sealing plate.

9. The method for preparing a composite side sealing plate according to claim 8, characterized in that: The hot pressing sintering temperature is 1500 to 1800℃, the hot pressing sintering pressure is 20 to 60MPa, and the hot pressing sintering time is 60 to 240min.

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