Influence of Al2O3 particles volume fraction on fracture mechanism in the Cu-Al2O3 system

The influence of Al2O3 particles volume fraction on the fracture mechanism in the Cu-Al2O3 system is analyzed by "in situ tensile test in SEM". It is shown that tensile strain first produces microcavities on matrix-particle i nterfaces due to decohesion of particles from the matrix. The cavities grow and coalesce first in the direction of rows of particles with growing stra in. Cracks develop in both directions: in the rows, and in the direction pe rpendicular to the rows, leading to final fracture. The deformation value a t fracture is dependent on Al2O3 particle volume fraction. A model explaini ng the fracture mechanism is introduced. (C) 2000 Elsevier Science B.V. All rights reserved.