CN-118754719-B - Three-dimensional netlike nanowire soft interface on surface of alumina fiber and preparation method thereof

CN118754719BCN 118754719 BCN118754719 BCN 118754719BCN-118754719-B

Abstract

The invention provides a three-dimensional netlike nanowire soft interface on the surface of an alumina fiber and a preparation method thereof, belonging to the technical field of alumina fiber reinforced ceramic composite materials. The preparation method comprises the steps of pretreating alumina fibers, fixing the pretreated alumina fibers by using a clamp, placing the pretreated alumina fibers into a chemical vapor deposition furnace, vacuumizing and heating the inside of the chemical vapor deposition furnace, preserving heat after heating, introducing trichlorosilane, hydrogen and argon for chemical vapor deposition, and cooling the pretreated alumina fibers to room temperature after deposition to obtain the alumina fibers with three-dimensional netlike nanowire soft interfaces on the surfaces. The surface area of the interface bonding of the fiber and the matrix is greatly increased due to the existence of the nanowire. When an external load acts on the oxide ceramic matrix composite material prepared from the fiber, the shear stress widely distributed on the surface of the nanowire at the interface of the fiber and the matrix can improve the energy dissipated by the composite material damage, thereby further improving the toughening effect.

Inventors

LIN HONGJIAO
SUN ZHONGYUAN
CAI XIANGYU
FENG TAO
WEN ZHIXUN
LIU HANGYI
LIU RUIXIAN

Assignees

西北工业大学

Dates

Publication Date: 20260505
Application Date: 20240710

Claims (5)

1. The application of the alumina fiber with the three-dimensional network nanowire soft interface on the surface in preparing the alumina fiber reinforced oxide ceramic matrix composite is characterized in that the preparation method of the alumina fiber reinforced oxide ceramic matrix composite comprises the following steps: Immersing alumina fiber with a three-dimensional netlike nanowire soft interface on the surface in alumina sol, placing the alumina fiber in a vacuum box for vacuum impregnation, wherein the vacuum degree is 0.1MPa, the impregnation time is 7h, taking out the alumina fiber after the impregnation, placing the alumina fiber in a drying furnace for drying treatment, wherein the drying temperature is 60-120 ℃ and the drying time is 10h, circularly impregnating and drying the alumina fiber until the mass increase percentage of the alumina fiber after the last drying is less than 5 percent, stopping circulation to obtain an Al 2 O 3 /SiC three-dimensional netlike nanowire soft interface/Al 2 O 3 composite blank, then placing the blank in a muffle furnace for high-temperature sintering, heating the blank to 800 ℃ at a heating rate of 10 ℃ per minute, keeping the temperature for 2h, continuously heating the blank to 1000 ℃ at a heating rate of 6 ℃ per minute, and keeping the temperature for 2h to obtain the alumina fiber reinforced oxide ceramic matrix composite; The preparation method of the alumina fiber with the three-dimensional netlike nanowire soft interface on the surface comprises the following steps: Pretreating an alumina fiber, fixing the alumina fiber by using a clamp, placing the pretreated alumina fiber into a chemical vapor deposition furnace, vacuumizing and heating the inside of the chemical vapor deposition furnace, preserving heat after heating, introducing trichlorosilane, hydrogen and argon for chemical vapor deposition, and cooling the alumina fiber to room temperature after finishing deposition to obtain the alumina fiber with the three-dimensional netlike nanowire soft interface on the surface; The alumina fiber is pretreated by sintering the alumina fiber at a high temperature, wherein the temperature rising rate of the high-temperature sintering is 400-600 ℃ per hour, the sintering temperature is 500-600 ℃, and the heat preservation time is 1-3 hours; vacuumizing the chemical vapor deposition furnace body to a vacuum degree of 1-3 Kpa, and raising the temperature to 1000-1300 ℃ at a temperature raising rate of 400-600 ℃ per hour; The middle surface of the clamp is provided with round air holes with the aperture of 3-5 mm, the distance between every two air holes is 7-10 mm, and the length of the clamp is 12-18 cm.
2. The application of the alumina fiber with the three-dimensional network nanowire soft interface on the surface in the preparation of the alumina fiber reinforced oxide ceramic matrix composite material, according to claim 1, wherein in the preparation method of the alumina fiber with the three-dimensional network nanowire soft interface on the surface, argon with the flow of 100-500 mL/min is introduced in the heating process to form a protective atmosphere.
3. The application of the alumina fiber with the three-dimensional network nanowire soft interface on the surface in the preparation of the alumina fiber reinforced oxide ceramic matrix composite material, according to claim 1, wherein in the preparation method of the alumina fiber with the three-dimensional network nanowire soft interface on the surface, the inside of a chemical vapor deposition furnace body is vacuumized and heated, and the heat preservation time is 3-6 hours after the heating is finished.
4. The application of the alumina fiber with the three-dimensional network nanowire soft interface on the surface in the preparation method of the alumina fiber reinforced oxide ceramic matrix composite material, which is characterized in that in the preparation method of the alumina fiber with the three-dimensional network nanowire soft interface on the surface, the inside of a chemical vapor deposition furnace body is vacuumized and heated, heat is preserved after the heating is finished, the flow rate of the introduced trichlorosilane is 0.1-0.4 g/min, the flow rate of the hydrogen is 1000-3000 mL/min, and the flow rate of the argon is 500-1000 mL/min in the heat preservation process.
5. The application of the alumina fiber with the three-dimensional network nanowire soft interface on the surface in the preparation of the alumina fiber reinforced oxide ceramic matrix composite material, which is disclosed in claim 1, is characterized in that in the preparation method of the alumina fiber with the three-dimensional network nanowire soft interface on the surface, after the deposition is completed, the introduction of the trichloromethylsilane and the hydrogen is stopped, and the flow of the argon is reduced to 100-500 mL/min.

Description

Three-dimensional netlike nanowire soft interface on surface of alumina fiber and preparation method thereof Technical Field The invention belongs to the technical field of alumina fiber reinforced ceramic composite materials, and particularly relates to a three-dimensional reticular nanowire soft interface on the surface of an alumina fiber and a preparation method thereof. Background The oxide ceramic has a plurality of excellent characteristics of high temperature resistance, oxidation resistance, high strength, low density, wear resistance and the like. In order to overcome the inherent brittleness of oxide ceramics, i.e., to enhance the toughness of oxide ceramics, the formation of oxide ceramic matrix composites by incorporating high strength oxide ceramic fibers into the oxide ceramic matrix is one of the most effective methods. Of these, alumina fiber reinforced Oxide ceramic matrix (Al 2O3/Oxide) composites are significantly representative. Although Al 2O3/Oxide composites have been developed later than superalloys and non-Oxide composites, there are advantages not possessed by the latter two. Compared with high-temperature alloy, the density of the Al 2O3/Oxide composite material is reduced by about 2/3, the fuel consumption is reduced due to the weight reduction characteristic, and the inherent high-temperature oxidation resistance and steam corrosion resistance of the Al 2O3/Oxide composite material are greatly improved in the reliability of the material compared with a non-Oxide composite material. And the Al 2O3/Oxide composite material has simple preparation process and low cost, and is an environment-friendly material. Based on the above-described advantages, al 2O3/Oxide composites have an irreplaceable position in a number of fields. In Al 2O3/Oxide composites, the interface, which refers to the discontinuous region between the fiber reinforcement and the matrix, is a determining factor in the properties of the composite. The introduction of the interfacial phase can significantly improve the performance of the Al 2O3/Oxide composite. For example, to prevent adverse chemical reactions between the fibers and the matrix and to avoid degradation of mechanical properties due to changes in the chemical composition of the fibers or the matrix. The most important function is however to increase the toughness of the composite, and when an applied load is applied to the composite, the energy dissipated by the composite in failure, i.e. the toughening effect, can be increased by the shear stress at the interface. To fully exert the toughening effect of this mechanism, the interfacial surface area of the fiber-matrix is a critical factor. The interface phase applied to the Al 2O3/Oxide composite material at present has a plurality of types, such as weak interface phase which is most widely applied, including PyC (pyrolytic carbon), single-site stone, zrO 2, BN and the like, and has the main functions of transmitting load and simultaneously preventing the fiber and a matrix from forming strong interface combination in the preparation and (high-temperature) service process, thereby improving the retention rate and fracture toughness of the strength of the material, and the porous interface phase has the characteristics of being low in density and strength, enabling cracks to deflect and protecting the fiber due to the existence of a microporous structure, and has more common application, and in addition, the porous interface phase and the porous-matrix interface phase are the other interface phases. However, for these diversified interfacial phases, which are all in the form of ceramic between the fibers and the matrix in the composite material, the inherent shape characteristics of the ceramic make the fiber-matrix bonding surface area relatively small, and the shear stress which can be generated is relatively low, so that the requirement of the high-toughness Al 2O3/Oxide composite material in certain specific environments cannot be met. Therefore, in order to meet the requirements of high toughness Al 2O3/Oxide composites in certain specific environments, it is highly desirable for those skilled in the art to provide a specific interfacial phase on the surface of alumina fibers and a method for preparing the same. Disclosure of Invention In order to overcome the defect of lower toughness of an Al 2O3/Oxide composite material, the invention provides a three-dimensional reticular nanowire soft interface on the surface of an alumina fiber and a preparation method thereof, and aims to toughen the Al 2O3/Oxide composite material. In order to achieve the above purpose, the invention provides a preparation method of a three-dimensional netlike nanowire soft interface on the surface of an alumina fiber, which comprises the following steps: Pretreating an alumina fiber, fixing the pretreated alumina fiber by using a clamp, placing the pretreated alumina fiber into a chemical vapor deposition furnace, vacuumi