Influence of particles in Cu-Al2O3 system on fracture mechanism

The influence of Al2O3 particles on fracture of the Cu-Al2O3 system is analyzed by 'in situ tensile test in SEM'. It has been shown, that tensile strain in the extrusion direction produced first micro cavities on matrix-particle interfaces due to decohesion of particles from the matrix. The cavities grow and coalesce first in the direction of rows of particles with growing strain, and then in direction perpendicular to the rows, leading to final fracture. The strain at fracture is dependent on Al2O3 particle volume fraction. The fracture mechanism is not dependent on Al2O3 particle volume fraction in the tested range. Model explaining the fracture mechanism was introduced. (C) 2001 Elsevier Science B.V. All rights reserved.