Effect of Particles Content on Microstructure, Mechanical Properties, and Electrochemical Behavior of Aluminum-Based Hybrid Composite Processed by Accumulative Roll Bonding Process

Effect of B₄C/SiC particles content on the microstructure, deformation, and electrochemical behavior of aluminum-based hybrid composite processed by accumulative roll bonding (ARB) was investigated. The ARB process was used to fabricate hybrid composites which consist of 1 and 2.5 wt pct of B₄C/SiC mixed particles as reinforcement. The microstructure of the fabricated hybrid composites after the ninth cycle of the ARB process exhibited an excellent distribution of B₄C/SiC particles in the aluminum matrix where no porosity was observed. In addition, with increasing the particle content in the aluminum matrix, the hybrid composites demonstrated higher tensile strength and lower elongation. The ARB-processed hybrid composites exhibited 3.12 and 3.37 times higher hardness for samples having 1 and 2.5 wt pct B₄C/SiC, respectively, than that of the annealed aluminum. Electrochemical impedance spectroscopy and potentiodynamic polarization curves revealed that the corrosion resistance dropped drastically by increasing the number of ARB cycles from 3 to 5. However, by further ARB processing, the corrosion resistance gradually increased, and finally, after 9 cycles reached to the values higher than those of 3-cycle ARB-processed samples.