Experimental investigation on strengthening mechanisms in Al-SiC nanocomposites and 3D FE simulation of Vickers indentation

In the present study, Al-4%SiC nanocomposite was manufactured with homogeneous and uniform distribution of SiC particles in Al matrix using accumulative roll bonding (ARB) technique. In addition high strength Al sheets were manufactured using ARB technique with the aim of comparison. Tensile test and microhardness were used to characterize the produced nanocomposite. Moreover, 3D FE model is presented to predict microhardness of the manufactured nanocomposite. The results show that at the initial stages of ARB process, particle free zones as well as particle clusters were observed in the microstructure of the nanocomposite. After 9 ARB passes, Al-4%SiC nanocomposite with uniform distribution of particles was produced. The tensile strength for ARBed Al and Al-4%SiC nanocomposite after nine passes is 3.19 and 4.09 times of the annealed Al 1050, respectively. Moreover, microhardness of ARBed Al and Al-4%SiC nanocomposite after nine passes is 3.63 and 4.76 times of the annealed Al 1050, respectively. Interestingly, the main strengthening mechanism is the grain refinement and dislocation strengthening due to rolling process, while the addition of SiC nanoparticles acts as a secondary strengthening source. Finally, the microhardness results predicted by the presented 3D FE model correlate well with the experimental results.