Grain boundary separation in transgranular cleavage cracking

摘要

The energy balance associated with the transmission of cleavage front across high angle grain boundary is analysed theoretically. On the one hand, if the distance between adjacent break-through points is small, their crack trapping effect tends to be pronounced. On the other hand, decreasing this distance promotes the separation of persistent grain boundary areas. The effective grain boundary toughness is also dependent on the profiles of penetrating front sections and the surface free energy of grain boundary. The most energetically favourable crack front transmission mode can be reached through a self-adjusting process.