The Grain Boundary fracture Behavior in Ni-base Bicrystals
镍基双晶体晶界断裂特性研究

The fracture behavior for Ni base bicrystals was studied by experiments. The fracture toughness for single and bicrystals of the metal was measured by three point bending test. The shielding effect from grain boundary was found in the test for grain cracked bicrystals with the crack normal to the grain boundary. It was also found that the fracture toughness exhibited a maximum value when the distance of crack tip from grain boundary reached a certain value. Based on theoretical analysis and with the help of numerical calculation, the mechanism for the grain boundary shielding effect was revealed.