Corrosion of Hot-Pressed Silicon Nitride in Alkali Carbonate Melts

Modeling the strain-rate dependence of fatigue life of hot- pressed silicon nitride

This paper presents the results of a micromechanical model used to explain the strain-rate dependence of the compression fatigue lives of amorphous and crystalline grain boundary phase; denoted by ABP and CBP silicon nitrides, respectively. When the strain-rate is changed from 400 to 0.01/s, the fatigue lives of both materials, evaluated at a peak stress of 3.2 GPa, increased by more than two o...

Dynamic Multiaxial Response of a Hot-Pressed Aluminum Nitride

Corrosion Characteristics of Silicon Carbide and Silicon Nitride

The present work is a review of the substantial effort that has been made to measure and understand the effects of corrosion with respect to the properties, performance, and durability of various forms of silicon carbide and silicon nitride. The review encompasses corrosion in diverse environments, usually at temperatures of 1000 °C or higher. The environments include dry and moist oxygen, mixt...

Microstructure and Fracture Toughness of Hot-Pressed Silicon Carbide Reinforced with Silicon Carbide Whisker

The effects of p-Sic whisker addition on the microstructural evolution and fracture toughness (K,c) of hot-pressed SIC were investigated. Most of the whiskers added disappeared during the densification process by transformation into the a-phase. The remaining whiskers acted as nuclei for grain growth, resulting in the formation of large tabular grains around the whiskers. The tabular grains aro...

Investigation of the Physical and Mechanical Properties of Hot-Pressed Boron Nitride/Oxide Ceramic Composites

Billets of hexagonal boron nitride powders (h-BN) were hot-pressed, varying the alignment of the platelike particles and the amount of oxide additives. Increasing either alignment of individual grains or the amount of additives was shown to increase flexural strength, to approximately 120 MPa at ambient temperatures. h-BN was shown to deflect cracks initially propagating normal to its basal pla...