Compressive properties and cracking behaviour of 3D interpenetrating hierarchical Al 2 O 3 p/steel composite

Abstract

A hierarchical-architectured Al₂O₃/40Cr steel composite was fabricated by squeeze casting. In the composite, the Al₂O₃ particulate-reinforced 40Cr steel matrix composite and pure 40Cr steel formed a 3D interpenetrating composite. The uniaxial compressive properties as well as the cracking behaviour, the strengthening and toughening mechanisms of the composite were investigated and discussed. The compressive strength, fracture strain, and elasticity modulus of the architectured composite are 903.5 MPa, 18.8%, and 197 GPa, which are 1.5, 4.0, and 1.7 times the values of the uniformly Al₂O₃p-reinforced composite, respectively. Special origination and propagation ways of the cracks in the composites were observed with a 3D X-ray microscope, and the contributions of 3D framework structure on the strengthening and toughening of the composite were confirmed.