Alumina ceramic material Its structure is corundum type, which has the characteristics of ionic bond, making the slip system far less than that of metal, which leads to the lack of certain toughness and plasticity. Therefore, the fracture toughness is low, which greatly limits the wide application of alumina ceramics.

This article gives a brief introduction to the current toughening methods of alumina porcelain and its main mechanism in order to bring readers some basic knowledge of ceramic toughening technology.

Common toughening methods for alumina ceramics

First, the layered structure is toughened

Natural materials, such as bamboo and shells, have good comprehensive properties because of their layered distribution. People learn from these natural structures, and adopt bionic structures to improve the brittleness and toughness of ceramic materials.

Layered composite ceramic materials are composed of multiple layers of materials. The elastic modulus and linear expansion coefficient of each layer are different, which leads to macro stress between the layers and compressive stress on the surface. When subjected to external force, it can absorb the strain energy to the greatest extent, and cause the crack to repeatedly deflect and twist along the interface. In this way, the purpose of improving surface properties and overall toughness is achieved.

For example: Al2O3 / Ni layered ceramics, which uses nickel's linear expansion coefficient to be about twice that of alumina, generates stress in the Al2O3 layer and has a large crack deflection ability, so the material has better toughness.

Laminated ceramics are a new type of material with a bright future, but their main disadvantages are that weak interlayers will reduce the strength of the material, and the properties of parallel and perpendicular to the interlayer direction are quite different and anisotropic. Therefore, industry experts have proposed the idea of using a strong interlayer, and prepared a ZTA / Al2O3 strong interlayer with an impact toughness of more than 10 Mpa.m1 / 2, which is 2.8 times that of ZTA materials and 5.6 times that of Al2O3 ceramics. Some scientists have simulated layered composite ceramics through computers and found that if the strength of the soft layer material is too high or too low, it will reduce the overall toughness, and increase th