Thermal expansion coefficient is one of the important parameters of materials. In nature, most materials exhibit high thermal expansion coefficient which would lead to the phenomenon of thermal-expansion and cold-contraction. Therefore, these materials usually have poor thermal shock resistance and cannot be used in the environment with great temperature changes. The signal distortion usually occurs because of the destruction of aerospace components and the deformation of electronic device resulted from the uneven temperature distribution. It is exciting that there are a few materials with negative thermal expansion coefficient, and their volume decreases with the increase of temperature. Based on the additivity of the expansion coefficient, the compounds with low coefficient of thermal expansion can be obtained by introducing the material with low or negative coefficient of thermal expansion into the high ones, which can remarkably improve their thermal shock resistance. Negative thermal expansion materials include isotropic negative thermal expansion materials and anisotropic negative thermal expansion mate-rials. Isotropic negative thermal expansion materials are mainly ZrV2-xPxO7 and ZrW2O8 series. Anisotropic negative thermal expansion materials mainly include β-eucryptite, perovskite series, A2M3O12series, M(CN)2 (M=Zn, Cd) series, oxides, zeolite series and metal organic frameworks (MOFs), etc. The β-eucryptite is usually used to adjust the thermal expansion coefficient of composite materials owing to its negative thermal expansion coefficient (α=-6.1×10-6 K-1), low density (2.67 g/cm3), good thermal shock resistance, dielectric properties and infrared radiation. Composite materials with negative thermal expansion or near zero thermal expansion can be fabricated by compounding with other materials, which can greatly improve the thermal shock resistance and dimensional stability of the materials, and thus prolong the life of the materials. Therefore, β-eucryptite has been used to manufacture low expansion ceramics, glass-ceramics, metal matrix composites applied as fillers for electrical equipment, electronic components, device sealants, aircraft high precision components, humidity sensor sensitive materials and lithium ion battery so-lid electrolytes. At the same time, due to the anisotropic thermal expansion property of β-eucryptite, the composites will have more residual stress and lower mechanical strength. In order to solve this problem, fibers or whiskers with high mechanical strength can be introduced to form three-phase composites with low expansion and high mechanical strength, which is beneficial to expand the application of materials in inertial missiles, optic fiber gyro and other aerospace applications. In this paper, the research status and progress of the low expansion two-phase or three-phase composites of metals, glass and ceramics are reviewed. The preparation method, thermal properties and application fields of these low expansion coefficient composites are summarized. The future development trends and application prospects of the composites are also discussed. © 2020, Materials Review Magazine. All right reserved.
