High-toughness wear-resistant material as well as preparation method and application thereof

Abstract

The invention belongs to the field of materials, and particularly discloses a high-toughness wear-resistant material and a preparation method and application thereof.The high-toughness wear-resistant material is prepared from 50 wt%-70 wt% of corundum, 20 wt%-40 wt% of mullite, 5 wt%-10 wt% of nanometer silicon carbide micro powder, 3 wt%-5 wt% of zirconium oxide, 2 wt%-5 wt% of nanometer titanium carbide micro powder, 1 wt%-3 wt% of rare earth oxide and 1 wt%-3 wt% of silicon oxide micro powder; the high-temperature strength and the thermal shock resistance are both considered through corundum-mullite combination, the wear resistance and the anti-scouring performance of the material are remarkably improved through introduction of the nano silicon carbide micro powder and the nano titanium carbide micro powder, the overall toughness of the material is improved through zirconium oxide, the material is made to adapt to mechanical shock at the high temperature, and the service life of the material is prolonged. Through the synergistic effect of the rare earth oxide and the silicon oxide micro powder, a stable protective film is formed at a high temperature, and the acid gas erosion resistance of the material is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the field of materials, and specifically relates to a high-strength and tough wear-resistant material and a preparation method and application thereof. Background Art

[0002] In metallurgical kilns, hot air pipes, bellows and other industrial equipment, materials need to be in a harsh environment of high temperature, corrosive gas and high-speed dusty flue gas for a long time; these environments require materials to have not only high strength and high toughness, but also excellent wear resistance and corrosion resistance;

[0003] However, traditional refractory materials (such as high-alumina bricks and corundum bricks) are prone to spalling or wear during use due to their poor toughness or insufficient wear resistance, resulting in a shortened equipment life. Summary of the invention

[0004] The purpose of the present invention is to provide a high-strength and wear-resistant material and a preparation method and application thereof, so as to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A high-strength and tough wear-resistant material comprises: 50-70wt% corundum, 20-40wt% mullite, 5-10wt% nano silicon carbide powder, 3-5wt% zirconium oxide, 2-5wt% nano titanium carbide powder, 1-3wt% rare earth oxide and 1-3wt% silicon oxide powder.

[0007] Preferably, the rare earth oxide is at least one of lanthanum oxide and cerium oxide.

[0008] Preferably, the high-toughness and wear-resistant material further comprises: 1-3 wt% graphite and 0.5-2 wt% hexagonal boron nitride.

[0009] A method for preparing a high-strength and tough wear-resistant material, comprising:

[0010] S1. Weigh corundum, mullite, nano silicon carbide powder, zirconium oxide, nano titanium carbide powder, graphite, and hexagonal boron nitride according to a certain ratio, add rare earth oxide and silicon oxide powder as auxiliary materials, and then use high-energy ball milling to mix the materials for ball milling.

[0011] S2, isostatic pressing the ball-milled material using an isostatic pressing process, during which 0.5-1 wt % of a PVA aqueous solution is added as a molding binder;

[0012] S3. The isostatically pressed material is subjected to spark plasma sintering and then subjected to heat treatment after sintering.

[0013] Preferably, the ball milling time in step S1 is 6 to 8 hours.

[0014] Preferably, the molding pressure of the isostatic pressing process in step S2 is 150-200 MPa.

[0015] Preferably, the temperature of the spark plasma sintering in step S3 is 1400-1600 degrees Celsius, the heating rate is controlled to be 100 degrees Celsius / minute, the holding time is 5 minutes, and during the sintering process, an inert gas is filled into the sintering chamber to form an oxygen-free environment.

[0016] Preferably, the temperature of the heat treatment after sintering in step S3 is 1200 degrees Celsius, and it is naturally cooled to room temperature after being kept at this temperature for 2 hours.

[0017] Preferably, during the spark plasma sintering in step S3, 0.5-1 wt% of calcium oxide and 1-3 wt% of silicon powder are added.

[0018] The invention discloses an application of a high-strength and tough wear-resistant material, wherein the high-strength and tough wear-resistant material is used as a metallurgical furnace flue, a hot air pipe and a bellows.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention takes into account both high-temperature strength and thermal shock resistance through the combination of corundum and mullite, significantly improves the wear resistance and erosion resistance of the material through the introduction of nano silicon carbide micropowder and nano titanium carbide micropowder, improves the overall toughness of the material by using zirconium oxide, and enables the material to adapt to mechanical impact at high temperatures, and forms a stable protective film at high temperatures through the synergistic effect of rare earth oxides and silicon oxide micropowder, significantly improving the material's resistance to acid gas erosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0022] Figure 1 It is a block diagram of the material composition of the present invention;

[0023] Figure 2 The figure is a flowchart of the method steps of the present invention. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0025] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0026] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0027] As attached Figure 1 As shown:

[0028] Embodiment 1: This embodiment provides a high-strength, toughness and wear-resistant material, including: 60wt% corundum, 30wt% mullite, 5wt% nano-silicon carbide powder, 3wt% zirconium oxide, 2wt% nano-titanium carbide powder, 2wt% rare earth oxide, and 1wt% silicon oxide powder.

[0029] The corundum in the material provides high temperature strength, chemical corrosion resistance and hardness foundation, while mullite provides good thermal shock resistance and creep resistance, and relieves thermal stress. The combination of corundum-mullite takes into account both high temperature strength and thermal shock resistance.

[0030] Nano-silicon carbide powder enhances the wear resistance and high temperature strength of the material, provides excellent anti-oxidation performance, and exhibits high stability in acidic environments. At the same time, nano-titanium carbide powder improves the anti-scouring ability, enhances the interface bonding force and wear resistance. The introduction of nano-silicon carbide powder and nano-titanium carbide powder significantly improves the wear resistance and anti-scouring performance of the material;

[0031] Zirconia will use the phase change toughening mechanism to improve the toughness and thermal shock resistance of the material, improve the overall toughness of the material, and make the material adapt to mechanical shock under high temperature;

[0032] Rare earth oxides will increase the interfacial bonding strength between corundum, mullite and nano-silicon carbide powder, zirconium oxide, and nano-titanium carbide powder, while enhancing the stability of the material in an acidic environment. Silica powder will form a protective glass phase during high-temperature sintering, further improving the material's resistance to acidic corrosion. Through the synergistic effect of rare earth oxides and silica powder, a stable protective film is formed at high temperatures, significantly improving the material's resistance to acidic gas corrosion.

[0033] The rare earth oxide is at least one of lanthanum oxide and cerium oxide. Lanthanum oxide tends to enhance the oxidation resistance and corrosion resistance of the material, while cerium oxide tends to optimize the grain boundary bonding strength and improve toughness and thermal shock resistance.

[0034] The high-strength, toughness and wear-resistant material also includes: 1wt% graphite and 1wt% hexagonal boron nitride. Graphite can reduce the friction coefficient of the material and improve the wear resistance of the material in a dynamic environment, and hexagonal boron nitride can further improve lubricity and corrosion resistance.

[0035] A method for preparing a high-strength and tough wear-resistant material, comprising:

[0036] S1. Weigh corundum, mullite, nano silicon carbide powder, zirconium oxide, nano titanium carbide powder, graphite, and hexagonal boron nitride according to the proportion, add rare earth oxide and silicon oxide powder as auxiliary materials, and then use high-energy ball milling to mix the materials for ball milling. During the ball milling process, the high-speed impact of the grinding balls causes the raw material particles to be continuously broken and cold-welded, promoting the full mixing of the components. At the same time, high-energy ball milling will also introduce a large number of lattice defects, increase the activity of the raw materials, and facilitate the subsequent sintering process. The ball milling time is set to 6 to 8 hours. This time range can not only ensure the full mixing of the raw materials, but also avoid excessive particle refinement and agglomeration due to too long ball milling, which affects the material properties;

[0037] S2. The ball-milled material is subjected to isostatic pressing using an isostatic pressing process. During the process, 0.5 wt% of a PVA aqueous solution is added as a molding binder to improve molding stability. The isostatic pressing process utilizes the characteristic of a liquid medium to uniformly transmit pressure, so that the material is subjected to the same pressure in all directions, thereby being able to prepare a green body with a complex shape and uniform density. The molding pressure is controlled within a range of 150 to 200 MPa. Within this pressure range, the raw material particles can be closely arranged, reducing internal pores and improving the density of the green body.

[0038] Add 0.5-1wt% PVA aqueous solution as a molding binder. PVA has good bonding properties and can form a thin film on the surface of the raw material particles to bond the particles together, thereby enhancing the strength and stability of the green body and preventing the green body from cracking or breaking during subsequent processing.

[0039] S3. The material after isostatic pressing is subjected to spark plasma sintering and heat treatment after sintering to further eliminate internal stress and stabilize material properties. Spark plasma sintering is a rapid sintering technology. At a high temperature of 1400 to 1600 degrees Celsius, the Joule heat generated by the pulse current and the external pressure are used to rapidly activate the surface of the powder particles and accelerate the atomic diffusion rate, thereby achieving rapid sintering. The heating rate is controlled at 100 degrees Celsius per minute. This faster heating rate can reduce the time for grain growth and is conducive to maintaining the fine grain structure of the material. structure to improve the strength of the material. The heat preservation time is 5 minutes. During the sintering process, inert gas is filled into the sintering chamber to form an oxygen-free environment. During this period, the atoms inside the material have enough time to diffuse and rearrange, and further densify. At the same time, 0.5-1wt% of calcium oxide and 1-3wt% of silicon powder are added during the spark plasma sintering process. Calcium oxide can react with impurities in the material, purify the grain boundaries, and improve the high-temperature performance of the material. Silicon powder reacts with other components at high temperature to form a new crystal phase and enhance the bonding strength of the material.

[0040] After sintering, the material is heat treated at 1200 degrees Celsius, kept at this temperature for 2 hours, and then naturally cooled to room temperature. This heat treatment process helps to eliminate the residual stress inside the material, further adjust the material's organizational structure, make the material's performance more stable, and through atomic diffusion and recrystallization at high temperature, the material's toughness and strength can be further optimized.

[0041] Specifically, the ball milling time in step S1 is 6 hours to ensure that the reinforcement phase is evenly dispersed in the matrix material.

[0042] Specifically, the molding pressure of the isostatic pressing process in step S2 is 200 MPa to ensure uniform density of the green body.

[0043] Specifically, in step S3, the temperature of spark plasma sintering is 1500 degrees Celsius, the heating rate is controlled to be 100 degrees Celsius / minute, the holding time is 5 minutes, and during the sintering process, an inert gas is filled into the sintering chamber to form an oxygen-free environment, and a dense microstructure is formed by rapid sintering.

[0044] Specifically, the temperature of the heat treatment after sintering in step S3 is 1200 degrees Celsius, and it is naturally cooled to room temperature after being kept at this temperature for 2 hours.

[0045] Specifically, during the spark plasma sintering process in step S3, 1 wt% of calcium oxide and 2 wt% of silicon powder are added. The calcium oxide can enhance the sintering activity of the material, and the silicon powder can improve the compactness of the material.

[0046] From the above, we can see that high-energy ball milling achieves uniform dispersion of raw materials and avoids agglomeration of the reinforcement phase; the combination of isostatic pressing and SPS sintering ensures the densification of the material and improves the overall performance.

[0047] Example 2: Application of a high-strength and tough wear-resistant material. The high-strength and tough wear-resistant material is used as a metallurgical kiln flue. The high-strength and tough wear-resistant material prepared in Example 1 is processed into lining bricks and installed in the metallurgical kiln flue. It runs continuously for 1200 hours under a high temperature of 600 to 1200°C and a dusty wind speed of 10m / s. The test results are as follows:

[0048] The lining bricks have no obvious wear or peeling and the surface is smooth;

[0049] The lining bricks have no cracks and excellent thermal shock resistance;

[0050] The service life is more than 50% longer than that of traditional high alumina bricks.

[0051] Comparative Example:

[0052] Raw material preparation: No nano silicon carbide powder is added, and the proportions of other raw materials are the same as in Example 1.

[0053] Preparation process: Prepare according to the preparation method of Example 1.

[0054] Performance test: The hardness and strength of the material are lower than those of Example 1, and the wear resistance in the simulated metallurgical furnace flue environment is also significantly reduced.

[0055] Comparative Example:

[0056] The high-strength and tough wear-resistant material prepared in Example 1 is compared with the traditional corundum brick material and the traditional high-alumina brick material, as follows:

[0057]

[0058]

[0059] Conclusion: The material exhibits excellent tensile strength and fracture toughness at high temperatures and can adapt to complex working conditions. Under particle scouring conditions, the wear rate is significantly reduced, and the stable protective film effectively resists acid gas erosion, extending the service life of the material. The material can operate stably in a high temperature fluctuation environment without cracking or peeling.

[0060] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0061] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0062] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A high-strength and wear-resistant material, characterized in that: include: Corundum 50-70wt%, mullite 20-40wt%, nano silicon carbide powder 5-10wt%, zirconium oxide 3-5wt%, nano titanium carbide powder 2-5wt%, rare earth oxide 1-3wt%, silicon oxide powder 1-3wt%.

2. A high-strength and wear-resistant material according to claim 1, characterized in that: The rare earth oxide is at least one of lanthanum oxide and cerium oxide.

3. A high-toughness wear-resistant material according to claim 1, characterized in that: The high-toughness and wear-resistant material further comprises: 1-3 wt % of graphite and 0.5-2 wt % of hexagonal boron nitride.

4. The method for preparing a high-strength and tough wear-resistant material according to claims 1 to 3, characterized in that: include: S1. Weigh corundum, mullite, nano silicon carbide powder, zirconium oxide, nano titanium carbide powder, graphite, and hexagonal boron nitride according to a certain ratio, add rare earth oxide and silicon oxide powder as auxiliary materials, and then use high-energy ball milling to mix the materials for ball milling. S2, isostatic pressing the ball-milled material, adding 0.5-1 wt % of PVA aqueous solution as a molding binder during the process; S3. The isostatically pressed material is subjected to spark plasma sintering and then subjected to heat treatment after sintering.

5. The method for preparing a high-strength and tough wear-resistant material according to claim 4, characterized in that: The ball milling time in step S1 is 6 to 8 hours.

6. The method for preparing a high-toughness wear-resistant material according to claim 4, characterized in that: The molding pressure of the isostatic molding process in step S2 is 150-200 MPa.

7. The method for preparing a high-toughness wear-resistant material according to claim 4, characterized in that: In step S3, the temperature of the spark plasma sintering is 1400-1600 degrees Celsius, the heating rate is controlled to be 100 degrees Celsius / minute, the holding time is 5 minutes, and during the sintering process, an inert gas is filled into the sintering chamber to form an oxygen-free environment.

8. The method for preparing a high-toughness wear-resistant material according to claim 4, characterized in that: The temperature of the heat treatment after sintering in step S3 is 1200 degrees Celsius, and it is naturally cooled to room temperature after being kept at this temperature for 2 hours.

9. The method for preparing a high-toughness wear-resistant material according to claim 4, characterized in that: During the spark plasma sintering process in step S3, 0.5-1 wt% of calcium oxide and 1-3 wt% of silicon powder are added.

10. The use of a high-toughness wear-resistant material according to any one of claims 1 to 3, characterized in that: The high-strength, toughness and wear-resistant material is used as a metallurgical furnace flue, hot air pipe and bellows.

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