Research Advances on Mechanical Property Improvement of Engineering Ceramic Joints

With the rapid development of science and technology, more and more stringent requirements for the properties of engineering materials are put forward. Engineering ceramics possess multiple advantages such as high strength and hardness, excellent resistance to high temperature and corrosion. With the gradual application of the engineering ceramics in extreme environment as alternatives for traditional metallic materials, the joining techniques of these ceramics appear to be one of the critical issues before used successfully. However, currently the properties of the joints of the ceramics are much lower than that of the matrix themselves, which are mainly due to two reasons. One is the accumulation of elastic strain energy in the ceramic matrix, and the other is the formation of the brittle reaction layer at the interface. In this review, various techniques emerging in recent years are introduced for the relief of the elastic strain energy of the ceramic base materials and the control of the thickness of the brittle reaction layer at the interface, whose basic theories, condition of use, examples of application, and disadvantages are analyzed in detail. At last, an outlook is provided for the theoretical research and technical procedures for the further development of mechanical properties of the joint structures of engineering ceramics.