Mechanical and thermal expansion properties of β-eucryptite prepared by sol–gel methods and hot pressing

The microstructures, mechanical properties and thermal expansion behavior of monolithic lithium aluminosilicate glass–ceramics, prepared by sol–gel method and hot pressing, were investigated by using X-ray diffraction, scanning and transmission electron microscopies, three-point bend tests and dilatometry. β-eucryptite appeared as main phase in the monolithic lithium aluminosilicate glass–ceramics. The glass ceramics exhibited high relative densities and the average flexural strength and fracture toughness values were 154 MPa and 2.46 MPa m1/2, respectively. The lithium aluminosilicate glass–ceramics hot pressed 1300 and 1350 °C demonstrated negative coefficient of thermal expansion, which was affected by amount and type of crystalline phases.

Research highlights
► Dense LAS glass–ceramics were fabricated by sol–gel and hot pressing technique.
► The LAS glass–ceramics have relative good mechanical properties.
► The negative thermal expansion behavior of LAS glass–ceramics was investigated.