FRACTURE MICROMECHANISMS OF DISPERSION-ST RENGTHENED CU-AL2O3 SYSTEMS

In the paper a study of fracture mechanism of a Cu-Al2O3 system by an ''in situ tensile test in SEM'' is presented. It is shown that during tensile strain the first cracks appear after decohesion of matrix-part icle interface. The following stress increase causes formation of micr ocracks in the clusters of Al2O3 particles as well as cracking of larg e Al2O3 particles. Afterwards, a ductile transcrystalline fracture app ears due to the cracks coalescence in the direction perpendicular to t he tensile stress. We suggest a model of fracture mechanisms in the in vestigated system.