Bonding interfacial characterization of SiCp/8009Al composite and A356 aluminum alloy using compound casting

Compound casting was performed to investigate the bonding of the molten A356 aluminum alloy cast onto the SiCp/8009Al composite that was preheated at 395-450 degrees C. The bonding strength was measured by carrying out a tensile test. The interfacial microstructures were characterized by scanning electron microscopy, energy dispersive spectroscope, X-ray diffraction and electron backscattered diffraction. The results showed that the bonding strength increased by 37% when the preheating temperature increased from 395 degrees C to 420 degrees C, and decreased by 6.8% as the preheating temperature further increased to 450 degrees C. A transition zone where the Al4.5FeSi phases were distributed was formed. The grain size of the Al4.5FeSi phase increased while its density decreased from the SiCp/8009Al composite to A356 aluminum alloy. The transition zone widened from 1350 pm to 3200 pm as the preheating temperature increased from 395 degrees C to 450 degrees C. In addition, at the preheating temperature of 450 degrees C, the fracture position changed from the interface between the A356 aluminum alloy and transition zone (at the preheating temperature of 395 degrees C and 420 degrees C) to the interior of the transition zone. The interface formation mechanism and its effect on the fracture mechanism were also discussed.