About this Abstract |
Meeting |
MS&T24: Materials Science & Technology
|
Symposium
|
Engineering Ceramics: Microstructure-Property-Performance Relations and Applications
|
Presentation Title |
Microscale Mechanical Properties of Silicon Nitride |
Author(s) |
Tatsuki Ohji, Motoyuki Iijima, Takuma Takahashi, Junichi Tatami |
On-Site Speaker (Planned) |
Tatsuki Ohji |
Abstract Scope |
In order to understand the mechanical properties of silicon nitride (Si3N4) ceramics, the deformation behavior and bending strength of Si3N4 grains and grain boundaries were measured by bending tests using microcantilever beam specimens.β-Si3N4 single crystals are plastically deformed at room temperature under high bending stress, and the yield stress depends on the crystal orientation. The critical resolved share stress of the primary slip system is determined to be below 1.5 GPa from the yield stress. The grain-boundary strength and toughness depended on the added rare earth ions as a sintering aid. Furthermore, degradation behaviors of Si3N4 ceramics, including the deterioration due to the contact with molten Al and the corrosion in sulfuric acid solution, were evaluated. The variation of the microscale properties appears in very short periods compared to the macroscale approaches, demonstrating the advantage in terms of rapid assessment of time-dependent degradation behaviors. |