Ceramic with light weight, high strength and high toughness and preparation method thereof

Abstract

The invention provides a ceramic with light weight, high strength and high toughness and a preparation method thereof. The method comprises the following steps: 1) presintering ceramic cenosphere powder to increase the strength of the ceramic cenosphere powder; 2) adding the presintered ceramic cenosphere powder in ceramic powder, adding the related additives; 3) selecting a moulding technology to mould the ceramic; 4) drying the obtained blank; and 5) sintering the dried blank. The invention provides the ceramic with light weight, high strength and high toughness and the preparation method thereof, wherein the ceramic cenosphere is a ceramic material toughened by the toughening body.

Description

technical field [0001] The invention relates to the field of inorganic non-metallic ceramics, in particular to a new method for preparing light-weight, high-strength and high-toughness ceramics. Background technique [0002] Due to the molecular arrangement and chemical bond properties of ceramic materials, the grain dislocation density in ceramic materials is low, the slip system is small, and the energy of crack nucleation and growth is small, thus determining the brittle nature of ceramic materials. Brittleness and low reliability severely limit the application range of ceramic materials. Only by improving the fracture toughness of ceramics, realizing the strengthening and toughening of materials, and improving their reliability and service life, can ceramic materials be widely used. Therefore, ceramic toughening technology has always been a hot spot in ceramic research. [0003] The essence of toughening is to introduce a mechanism to absorb fracture energy in the mater...

AI Technical Summary

Problems solved by technology

The particle dispersion toughening operation is relatively simple, but the toughening effect is not significant; the introduction of nano-scale particles into the ceramic matrix can achieve a good strengthening and toughening effect, but the preparation of nano-powders grows rapidly during the sintering process, making it difficult to prepare Real nanocrystalline ceramic products; phase change toughening has a good effect at room temperature, but toughening fails at high temperatures (above 1000 ° C); ceramic fiber (or whisker) reinforced and toughened ceramic matrix composites It has excellent mechanical properties at room temperature and high temperature. The preparation process of whiskers as a toughening phase is simpler. The disadvantage of fiber and whisker toughening is that it is difficult to ensure the uniformity of mixing, and whiskers are harmful to the human body, and the application is limited.

In recent years, inspired by the relationship between the structure and performance of biological materials in the biological world, people have designed bionic structures of ceramic materials, such as imitating bamboo and wood structures to make Si 3 N 4 / BN fiber monolithic ceramic material, imitating shell nacre structure made of Si 3 N 4 / BN layered structure ceramic materials, etc., also have a certain toughening effect, but its disadvantages are mainly that the properties parallel to and perpendicular to the interlayer direction are quite different, showing anisotropy

At the same time, the toughness of the layered and fiber monolithic ceramics is improved at the expense of strength, that is, although the toughness is greatly improved, the strength is reduced.

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