Fabrication of near-zero thermal expansion of fully dense β-eucryptite ceramics by microwave sintering

Microwave heating is proposed as the non-conventional technique for the sintering of optimal lithium aluminosilicate compositions of the β-eucryptite system. The coefficient of thermal expansion and mechanical properties of the sintered samples has been studied under the influence of microwave heating. The ad hoc synthesized β-eucryptite together with the microwave sintering technique developed in this work open the opportunity to produce breakthrough materials with low or negative coefficient of thermal expansion and excellent mechanical properties, as Youngʹs modulus of 110 GPa. The combination of rapid heating with low energy applied by the microwave technology (eco-friendly process) and the dramatic reduction in cycle time allows densification without glass phase formation. Results of the coefficient of thermal expansion of the β-eucryptite ceramics presented here under cryogenic conditions will be of value, for example, in the future design of new composite materials for space applications.