Development of a Near Zero Thermal Expansion Porous Material

A porous material having near zero thermal expansion (NZTE) around room temperature was developed. This material was prepared by sintering a mixture of SiC, vitrified bonding material (VBM) and LiAlSiO4 at 850°C. LiAlSiO4 was added in different weight proportions, and it was found that a change in the amount of LiAlSiO4 leads to a material with NZTE at room temperature, porosity around 50%, and Young's modulus around 14 GPa. Through X-ray diffraction (XRD) and scanning electron microscopy (SEM) it was determined that no reaction occurred between SiC and LiAlSiO4 during sintering, and they are joined by the VBM, which melted at the sintering temperature. In conclusion, the addition of LiAlSiO4 and VBM to SiC, allowed the development of porous SiC materials having NZTE at room temperature.