STRENGTH CHARACTERISTICS OF STRUCTURAL CERAMICS

Development of Superplastic Structural Ceramics

Superplastic structural ceramics (Y-TZP, A1203, Si3N4, and their composites) that can withstand biaxial stretching to large strains have been developed recently. Microstructural design of these ceramics first requires an ultrafine grain size that is stable against coarsening during sintering and deformation. A low sintering temperature is a necessary, but not a sufficient, condition for achievi...

Broadline NMR of Structural Ceramics

Magic angle spinning (MAS) has become the most widely used NMR technique for the study of inorganic solids. This popularity has come about because MAS removes the effects of chemical shift anisotropy, permitting acquisition of chemical shift spectra in these materials. However, there are two weaknesses to the MAS technique, which are accentuated in the study of structural ceramics. The first di...

Strength of Polycrystalline Ceramics under Shock Compression

Flexural strength of veneering ceramics for zirconia.

OBJECTIVES The flexural strengths of veneering ceramics for zirconia were compared. METHODS With 10 different veneering ceramics for zirconia (test group) and three different veneering ceramics for the metal-ceramic technique (control group) three-point flexural strength and biaxial flexural strength according to ISO 6872: 1995 as well as four-point flexural strength according to EN 843-1: 20...

Laminar Ceramics That Exhibit a Threshold Strength.

Thin compressive layers within a laminar ceramic arrest large cracks (surface and internal) and produce a threshold strength. This phenomenon increases the damage tolerance of ceramics and will allow engineers to design reliable ceramic components for structural applications. The stress intensity factor derived for a crack sandwiched between two compressive layers suggests that the threshold st...