Effect of specimens' orientations on fracture toughness of 15%SiCp/2009Al composites

The facture toughness of 15%SiCp/2009Al composite fabricated by powder metallurgy (PM) method and the effect of different specimen orientations on the fracture toughness of the composite were studied. The results showed that the KIC of the compact tension specimens of L-R orientation was evidently higher than that of the compact tension specimens of R-L orientation and C-R orientation. Fractographic analysis revealed that fracture in the compact tension specimens of L-R orientation mainly resulted from cleavage crack of SiCp with lower probabilities of crack in large area of the matrix alloy. There was no phenomenon of SiCp/alloy matrix interfacial debonding. Fracture of large number of SiCp particle and high interface combination strength would improve the fracture toughness of the composite.