A kind of hf-al-si complex oxide ceramic fiber and preparation method thereof

Abstract

The invention discloses a Hf-Al-Si composite oxide ceramic fiber and a preparation method thereof, in which HfO 2 , Al 2 o 3 and SiO 2 The weight ratio of the fibers is 1-50:20-94:5-40; the average diameter of the fibers is 5-15 μm, and the tensile strength is not less than 1.5 GPa. The preparation method comprises the preparation of Hf-Al-Si multiphase oxide ceramic precursor, and after the precursor is melt-spun, sequentially undergoes non-melting, inorganicization and high-temperature sintering treatment to obtain Hf-Al-Si multiphase oxidation The softening point of the Hf-Al-Si composite oxide ceramic precursor is 85-135°C. The Hf-Al-Si composite oxide ceramic fiber provided by the present invention has a higher temperature resistance grade, and the mechanical properties drop after high temperature treatment is small, and the precursor of the Hf-Al-Si composite oxide ceramic The body can exist in a solid state, so that it can be dissolved by a specific solvent, and can also be melted at the same time, which improves the applicability and is suitable for popularization.

Description

technical field [0001] The invention belongs to the technical field of composite materials, and in particular relates to a Hf-Al-Si composite oxide ceramic fiber and a preparation method thereof. Background technique [0002] Alumina fiber is a high-performance inorganic fiber. It starts with Al 2 o 3 As the main component, some also contain other metal oxides such as ZrO 2 and SiO 2 Etc., with long fiber, short fiber, whisker and other forms. The outstanding advantages of alumina fiber are high strength and high modulus. It has excellent mechanical properties in an air atmosphere of 1000-1200 ° C. It also has the advantages of small thermal conductivity, low thermal expansion coefficient, and good thermal shock resistance. In addition, compared with other high-performance inorganic fibers such as silicon carbide fibers, the raw material cost of alumina fibers is low, and the production process is simple, so it has huge market prospects in the fields of aerospace and ci...

AI Technical Summary

Problems solved by technology

This patent is also prepared by the sol-gel method, and the sodium-lithium ions brought by lithium tantalate and sodium hydroxide remaining in the system will also affect the high-temperature mechanical properties of the finished fiber to a certain extent

[0008] It can be seen that although the continuous alumina fiber prepared by the sol-gel method has been commercialized, the method still has the following disadvantages: the sol-gel spinning process is sensitive to ambient temperature and humidity, especially in summer when the ambient humidity is high. The primary fiber filaments are easy to merge and even stick together to form a paste; the sol contains chloride ions, and hydrogen chloride corrosive gas will be generated in the later heat treatment process, which will cause hidden dangers to the environment, equipment and workers' safety

However, due to the strong metallicity of Al atoms, it is difficult to prepare alumina precursors that can be melted, so there are few reports on the preparation of alumina fibers by melt spinning of precursors.

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