阅读说明：本技术 SiC晶须增强AlN陶瓷结合C复合耐火材料及其制备方法 (SiC whisker reinforced AlN ceramic bonded C composite refractory material and preparation method thereof ) 是由 余超 吴欣欣 邓承继 丁军 祝洪喜 郑永翔 于 2020-06-09 设计创作，主要内容包括：本发明涉及一种SiC晶须增强AlN陶瓷结合C复合耐火材料及其制备方法。其技术方案是：将装有Al<Sub>4</Sub>SiC<Sub>4</Sub>坯体的坩埚置于高温气压炉内,真空条件下加热至1150～1250℃,充氮气至0.1～5MPa,保压条件下升温至1600～1800℃,保温保压10～300min,制得制品。或将装有Al<Sub>4</Sub>SiC<Sub>4</Sub>坯体的坩埚置于高温气压炉内,在真空条件下加热至1150～1250℃,用5～10min充氮气至0.1～1MPa,保压条件下加热至1500～1600℃,保温保压10～300min；再用5～10min充氮气至1.2～7MPa,保压条件下继续加热至1600～1800℃,保温保压10～60min,制得制品。所述坯体是将Al<Sub>4</Sub>SiC<Sub>4</Sub>粉体模压成型或将Al<Sub>4</Sub>SiC<Sub>4</Sub>粉体模压成型后再等静压成型。本发明所制制品抗氧化性能优异、致密度高且力学性能好。(The invention relates to a SiC whisker reinforced AlN ceramic bonded C composite refractory material and a preparation method thereof. The technical scheme is as follows: will be filled with Al 4 SiC 4 And (3) placing the crucible of the blank body in a high-temperature air pressure furnace, heating to 1150-1250 ℃ under a vacuum condition, filling nitrogen to 0.1-5 MPa, heating to 1600-1800 ℃ under a pressure maintaining condition, and keeping the temperature and the pressure for 10-300 min to obtain the product. Or will be charged with Al 4 SiC 4 Placing a crucible of the blank body in a high-temperature air pressure furnace, heating to 1150-1250 ℃ under a vacuum condition, filling nitrogen to 0.1-1 MPa for 5-10 min, and heating to 1500 ℃ under a pressure maintaining conditionKeeping the temperature and the pressure for 10-300 min at the temperature of-1600 ℃; and then filling nitrogen for 5-10 min to 1.2-7 MPa, continuously heating to 1600-1800 ℃ under the pressure maintaining condition, and preserving heat and pressure for 10-60 min to obtain the product. The blank is prepared by mixing Al 4 SiC 4 Molding the powder or mixing Al 4 SiC 4 And carrying out isostatic pressing after the powder is subjected to compression molding. The product prepared by the invention has excellent oxidation resistance, high density and good mechanical property.)

1. A preparation method of a SiC whisker reinforced AlN ceramic bonded C composite refractory material is characterized by comprising the following steps:

mixing Al₄SiC₄Placing the blank into a graphite crucible, then placing the crucible into a high-temperature air pressure furnace, and heating the crucible to 1150-1250 ℃ from room temperature under the condition that the vacuum degree is less than or equal to 10 Pa; then, filling nitrogen for 5-10 min to 0.1-5 MPa, heating to 1600-1800 ℃ under the pressure maintaining condition, preserving heat and maintaining pressure for 10-300 min, and cooling to room temperature to prepare the SiC whisker reinforced AlN ceramic bonded C composite refractory material;

or mixing Al₄SiC₄Placing the blank into a graphite crucible, then placing the crucible into a high-temperature air pressure furnace, heating the crucible to 1150-1250 ℃ from room temperature under the condition that the vacuum degree is less than or equal to 10Pa, filling nitrogen to 0.1-1 MPa for 5-10 min, heating to 1500-1600 ℃ under the pressure maintaining condition, and preserving heat and pressure for 10-300 min; then, filling nitrogen for 5-10 min to 1.2-7 MPa, continuously heating to 1600-1800 ℃ under the pressure maintaining condition, preserving heat and maintaining pressure for 10-60 min, and cooling to room temperature to prepare the SiC whisker reinforced AlN ceramic bonded C composite refractory material;

the Al is₄SiC₄The blank is a blank I or a blank II: the blank I is prepared from Al₄SiC₄The powder is molded under the condition of 5-50 MPa to obtain Al₄SiC₄A blank body I; the blank II is prepared by mixing Al₄SiC₄The powder is 5-50Molding under MPa, and then carrying out isostatic pressing under the condition of 100-200 MPa to obtain Al₄SiC₄And (5) a blank body II.

2. The method of claim 1, wherein the Al is selected from the group consisting of Al, Si, Cu, Al, Si, Al₄SiC₄The purity of the powder is more than or equal to 98.0 wt%, and the granularity is less than or equal to 74 mu m.

3. The method for preparing the SiC whisker reinforced AlN ceramic-bonded C composite refractory material according to claim 1, wherein the purity of the nitrogen is not less than 99.999%.

4. A SiC whisker reinforced AlN ceramic bonded C composite refractory, characterized in that the SiC whisker reinforced AlN ceramic bonded C composite refractory is the SiC whisker reinforced AlN ceramic bonded C composite refractory prepared by the method for preparing the SiC whisker reinforced AlN ceramic bonded C composite refractory according to any one of claims 1 to 3.

Technical Field

The invention belongs to the technical field of non-oxide ceramic combined carbon composite refractory materials. In particular to a SiC whisker reinforced AlN ceramic bonded C composite refractory material and a preparation method thereof.

Background

The carbon material has the characteristics of light weight, low thermal expansion coefficient, excellent high-temperature mechanical property, good electric conductivity and heat conductivity, and strong corrosion resistance and slag resistance, and is widely applied to the fields of aerospace, national defense, sports, medicine and the like. However, the carbon material is oxidized at 400 ℃ and has low strength, so that the carbon material is difficult to form chemical combination with other substances, and the application of the carbon material in high-temperature industries is limited. In order to apply the carbon material to high-temperature structural components, the most effective method is to introduce a ceramic material into the carbon material to prepare a ceramic-carbon composite material, and the result shows that the method can effectively improve the strength, oxidation resistance and other properties of the single-phase carbon material.

The wide range of applications of oxide ceramic-carbon composites in existing refractory materials has been relatively mature, such as aluminum carbon (Al)₂O₃-C) refractory material (J.Ding, C.Yu, J.P.Liu, et al.effects of silicon powder binder content of said properties and interfacial bonding of finished Al₂O₃-C refractories[J]Materials Chemistry and Physics,206,2018,193-203) for use in bulkhead, ladle or submerged nozzle devices in the steel industry, which Materials, while having poor wettability and corrosion resistance to liquid slag, are susceptible to oxidation at high temperatures and have a low service life. The non-oxide ceramic-carbon composite material has the characteristics of light weight and high strength as a novel refractory material, can be applied to ultra-high temperature extreme environments, and is attracted by more and more scholars in recent years, such as S.BZhou et al (S.B.Zhou, Z.Wang, W.Zhang, Effect of graphite flash orientation on microstructure and mechanical properties of ZrB₂SiC-graphite composite, Journal of Alloys and composites, 485,2009,181-185.) with ZrB with a particle size of 2 μm₂Fine powder, SiC fine powder with the particle size of 2 mu m and flake graphite with the particle size of 15 mu m and the thickness of 2 mu m are taken as raw materials, ball milling, wet mixing, drying and the like are carried out, and ZrB is prepared by sintering at 1900 ℃ for 1h in argon atmosphere under 30MPa of one-way pressure by adopting a hot-pressing sintering method₂-SiC-graphite composite material. The materials prepared by the preparation method have the defects of insufficient raw material mixing, uneven distribution of chemical components of products, high-temperature and high-pressure environment required in the preparation process, harsh conditions, high cost and the like, and the materials usually adopt fine powder as the raw material, have no framework structure constructed by coarse particle aggregates of the existing refractory materials, and cannot form strong chemical bond combination due to the fact that ceramics and carbon particles are combined in a simple physical stacking mode, so that the mechanical property of the materials is poor. Chen et al (W.W.Chen, Y.Miyamoto, T.Tojo, M.Naito, Dentification and properties of AlN Ceramic bonded carbon, Journal of the European Ceramic Society,32,2012, 245-.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method of a SiC whisker reinforced AlN ceramic bonded C composite refractory material with simple process and low cost.

In order to achieve the purpose, the invention adopts the technical scheme that:

mixing Al₄SiC₄Placing the blank into a graphite crucible, then placing the crucible into a high-temperature air pressure furnace, and heating the crucible to 1150-1250 ℃ from room temperature under the condition that the vacuum degree is less than or equal to 10 Pa; and then filling nitrogen for 5-10 min to 0.1-5 MPa, heating to 1600-1800 ℃ under the pressure maintaining condition, keeping the temperature and the pressure for 10-300 min, and cooling to room temperature to obtain the SiC whisker reinforced AlN ceramic bonded C composite refractory material.

Or mixing Al₄SiC₄Placing the blank into a graphite crucible, then placing the crucible into a high-temperature air pressure furnace, heating the crucible to 1150-1250 ℃ from room temperature under the condition that the vacuum degree is less than or equal to 10Pa, filling nitrogen to 0.1-1 MPa for 5-10 min, heating to 1500-1600 ℃ under the pressure maintaining condition, and preserving heat and pressure for 10-300 min; and then filling nitrogen for 5-10 min to 1.2-7 MPa, continuously heating to 1600-1800 ℃ under the pressure maintaining condition, preserving heat and maintaining pressure for 10-60 min, and cooling to room temperature to obtain the SiC whisker reinforced AlN ceramic bonded C composite refractory material.

The Al is₄SiC₄The blank is a blank I or a blank II: the blank I is prepared from Al₄SiC₄The powder is molded under the condition of 5-50 MPa to obtain Al₄SiC₄A blank body I; the blank II is prepared by mixing Al₄SiC₄The powder is molded under the condition of 5-50 MPa, and then is molded under isostatic pressure under the condition of 100-200 MPa to obtain Al₄SiC₄And (5) a blank body II.

The Al is₄SiC₄The purity of the powder is more than or equal to 98.0 wt%, and the granularity is less than or equal to 74 mu m.

The purity of the nitrogen is more than or equal to 99.999 percent.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the beneficial effects that:

the invention only adopts single Al₄SiC₄The powder is used as a raw material, and the chemical components of the product are uniformly distributed and have a microstructure; the SiC whisker reinforced AlN ceramic bonded C composite refractory material is prepared by firstly preparing a blank by adopting a method of die pressing or combination of die pressing and isostatic pressing, and then directly placing the blank in a high-temperature air pressure furnace to be sintered by using an air pressure sintering method in a nitrogen atmosphere, has simple process and can prepare products with complex shapes; the density of the blank is obtained by combining mould pressing and isostatic pressingMore uniform and consistent, and less product defects.

Compared with a one-step air pressure sintering method, the SiC whisker reinforced AlN ceramic bonded C composite refractory material prepared by the two-step air pressure sintering method has higher density and more excellent mechanical property; the SiC whisker reinforced AlN ceramic bonded C composite refractory material prepared by the invention is sintered at 1600-1800 ℃ and 0.1-7 MPa, has low preparation temperature, small pressure intensity and simple conditions, and can obviously reduce the production cost.

The SiC whisker reinforced AlN ceramic bonded C composite refractory material prepared by the invention forms a network structure of AlN-coated SiC whiskers and C, wherein SiC whiskers formed in situ are uniformly dispersed among C aggregates to form a continuous SiC whisker network, so that the dispersed and coated carbon aggregates are reinforced by a whisker network framework, and AlN and SiC are similar in structure and are easier to form effective chemical bonding, so that the SiC whisker network and the AlN ceramic framework can form close chemical bonding, and the weak bonding between the AlN ceramic and the carbon aggregates is reinforced by the SiC whisker network, so that the prepared SiC whisker reinforced AlN ceramic bonded C composite refractory material is good in mechanical property, excellent in oxidation resistance and high in compactness.

The SiC whisker reinforced AlN ceramic bonded C composite refractory material prepared by the invention has the relative density of 75.8-90% and the breaking strength of 106.9-200 MPa through detection.

Therefore, the preparation process is simple and low in cost, and the prepared SiC whisker reinforced AlN ceramic bonded C composite refractory material has uniform chemical component distribution and microstructure, excellent high-temperature oxidation resistance, high density and good mechanical property.

Drawings

FIG. 1 is an XRD pattern of a SiC whisker reinforced AlN ceramic bonded C composite refractory material prepared by the invention;

FIG. 2 is a TEM image of the SiC whisker reinforced AlN ceramic bonded C composite refractory shown in FIG. 1.

Detailed Description

The invention will now be further described with reference to the accompanying drawings and detailed description, without limiting its scope.

In this embodiment:

the Al is₄SiC₄The purity of the powder is more than or equal to 98.0 wt%, and the granularity is less than or equal to 74 mu m.

The purity of the nitrogen is more than or equal to 99.999 percent.