Tensile behavior of a SiCw/Al composite under TEM

The processes of deformation, crack initiation and growth in SiCw/Al composite have been observed by means of the in-situ straining techniques of transmission electron microscopy. The testing results indicated that a great deal of dislocations would arise around the grain boundaries and whiskers in the early stage of deformation. The cracks are initiated mainly in whisker-rich regions and from the fracture of the whiskers injured during the process of composite preparation. The whiskers and grain boundaries play an important role to impede the crack growth. When the crack is perpendicular to the whisker, the crack tip around the whisker would blunt and then expended along the region near interface. As a crack is parallel to whisker, the crack tip would blunt near the end of the whisker and propagate along the side near the interface.