Definition - What does Transgranular Fracture mean?
A transgranular fracture is a fracture that follows the pattern of grains in the individual lattices of the material. This is one type of brittle fracture.
Transgranular fractures are also known as transcrystalline fractures.
Corrosionpedia explains Transgranular Fracture
In a transgranular fracture, the fracture travels through the grain of the material. The fracture changes direction from grain to grain due to the different lattice orientation of atoms in each grain. In other words, when the crack reaches a new grain, it may have to find a new path or plane of atoms to travel on because it is easier to change direction for the crack than it is to rip through. Cracks choose the path of least resistance.