Crack propagation along grain boundaries in sintered silicon nitride (Si3N4 was investigated by in-situ straining experiments at room temperature in a transmission electron microscope, using a high-precision microindenter. Using this in-situ technique, cracks introduced were introduced in situ and observed propagating along grain boundaries. High-resolution electron microscopy observation revealed that the propagation of the intergranular crack takes place at an interface between the Si 3N4 grains and the intergranular glassy film (IGF). This suggests that the Si3N4/IGF interface has a relatively high excess energy. The result was compared with a theoretical calculation using a molecular dynamics simulation.
ASJC Scopus subject areas
- Condensed Matter Physics