Abstract: Glass-ceramics with α-cordierite(2MgO·2Al₂O₃·5SiO₂) as main crystal phase, having excellent dielectric property, are perfect
materials for microwave parts of a medium apparatus. However, the thermal expansion coefficient of the material is not high enough for some special
applications. Now, a novel glass-ceramics with suitable thermal expansion coefficient (47.7×10^-7/℃) and excellent dielectric
property (ε=5.1，tgδ<10^-3) was developed. Crystallization process and the thermal expansion coefficient changes of the material was
studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and thermal expansion property testing. The results show that the thermal
expansion coefficient changes respond to crystal phase proportion and transition.

Key words: glass-ceramics, thermal expansion coefficient, dielectric property, crystal phase