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

摘要

The microstructures, mechanical properties and thermal expansion behavior of monolithic lithium alu-minosilicate 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 dilatom-etry. p-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 m~(1/2), respectively. The lithium aluminosilicate glass-ceramics hot pressed 1300 and 1350 ℃ demonstrated negative coefficient of thermal expansion, which was affected by amount and type of crystalline phases.