Hf-Al-Si multiphase oxide ceramic fiber and preparing method thereof

Abstract

The invention discloses an Hf-Al-Si multiphase oxide ceramic fiber and a preparing method thereof. The weight ratio of HfO2 to Al2O3 to SiO2 in the ceramic fiber is (1-50):(20-94):(5-40), the averagediameter of the fiber is 5-15 micrometers, and the tensile strength is not smaller than 1.5 GPa. The preparing method comprises the steps of preparing an Hf-Al-Si multiphase oxide ceramic precursor, conducting melt spinning on the precursor, and afterwards, conducting non-melting treatment, inorganic treatment and high-temperature sintering treatment in sequence to obtain the Hf-Al-Si multiphase oxide ceramic fiber, wherein the softening point of the Hf-Al-Si multiphase oxide ceramic precursor is 85-135 DEG C. The Hf-Al-Si multiphase oxide ceramic fiber has a high temperature-resistance grade,and the reduction degree of mechanical performance after high-temperature treatment is small; moreover, the Hf-Al-Si multiphase oxide ceramic precursor can exist in the form of solids, can be dissolved with a specific solvent, and can also be molten, the applicability is improved, and the Hf-Al-Si multiphase oxide ceramic fiber is suitable for application and 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...

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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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