Design of higher allowable temperature range for zero thermal expansion composites considering stiffness characteristic

The macroscopic zero thermal expansion of material could be obtained through combining two kinds of materials with different positive thermal expansion coefficients within a unit cell. These composites usually possess higher thermally geometric stability in the large temperature fluctuation. However, it readily produces excessive thermal stress on the interface between the two constituent materials and therefore limits the allowable temperature range of the material. A new evaluation index of the maximum thermal stress of unit temperature rise was resorted to perform allowable temperature and stiffness analyses for the three types of typical bending-dominated zero expansion materials. Both the analytic and numerical simulation methods were adopted and the influences of cell design parameters on these aspects were also discussed. The results show that when the designed zero expansion attribute is achieved, the high stiffness and high allowable temperature range can be obtained at the same time if the reasonable constituent materials and structural parameters are selected. Copyright ©2021 Acta Materiae Compositae Sinica. All rights reserved.