Pressureless sintering of large-scale fine structural alumina matrix ceramic guideway materials

In the present work, diopside is introduced in alumina matrix ceramic materials as a sintering aid. Large-scale fine structural alumina matrix ceramic guideway materials are fabricated by the technology of pressureless sintering, during which transient liquid phase sintering comes into being and new phases such as 3Al2O3·2SiO2, CaO·Al2O3·2SiO2 and CaO·6Al2O3 are produced by the chemical reactions taking place among alumina and the additives. The densification rate of the guideway composites as a function of diopside content is discussed. The hardness, the fracture toughness and the bending strength of the guideway products are tested. Meanwhile, the effects of diopside on mechanical properties, fracture mechanism and porosity of large-scale fine structural alumina matrix ceramic guideway materials are analyzed.