Fabrication and characterization of hybrid composite strips with homogeneously dispersed ceramic particles by severe plastic deformation

Abstract

In the present work, accumulative roll bonding (ARB) process was used as an alternative method for manufacturing Al/B4C/SiC hybrid composites. Uniaxial tensile tests and microhardness measurements were carried out on ARBed specimens and their characteristics were investigated by means of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and the Archimedes method. It was found that with increasing the ARB cycles, the distribution of B4C and SiC particles was improved in the aluminum matrix. After the 11th cycle, the hybrid composite demonstrated a uniform distribution of the reinforcement particles with strong bonding between the particles and the matrix material without any trace of porosities. The tensile strength of the composite increased with ARB cycle and reached to maximum value of 255MPa at 11th cycle; which was 3.19 and 1.35 times higher than the annealed aluminum and monolithic aluminum, respectively. The microhardness results suggested that by increasing the number of cycles, hardness increased rapidly at first stages and then dwindled at last stages. Finally, fractography results indicated that the fracture mode in hybrid composites consisted of shear ductile rupture, dimples and shear zones.