Study of mechanical properties and wear resistance of nanostructured Al 1100/TiO <sub>2</sub> nanocomposite processed by accumulative roll bonding
Ismail Najjar, M. Elmahdy
Abstract
Aluminum (Al) composites have been extensively developed for automotive applications due to their high specific strength. Therefore, in this study, an Al-titanium dioxide (TiO 2 ) nanocomposite was processed using the accumulative roll bonding (ARB) process. The mechanical characteristics of monolithic and nanocomposites specimens made with 0, 1, 2, and 3 wt% TiO 2 nanoparticles as reinforcement were studied at several ARB passes. According to the microstructure of the composites, rolling after five passes achieves a homogenous distribution of reinforcement particles, ultrafine and elongated grains of the matrix. After five ARB passes, the TiO 2 particles were uniformly dispersed. Finally, scanning electron microscopy and energy dispersive spectroscopy revealed that the Al-TiO 2 nanocomposite had an appropriate dispersion of TiO 2 nanoparticles. Vickers microhardness improves as the number of accumulative roll bonding passes increases. Furthermore, after five passes, Vickers microhardness testing revealed that the sample with 3%TiO 2 has the greatest hardness value of 112 HV, which is significantly greater than the 44 HV hardness value of the ARB-processed aluminum. The mechanical properties of the specimens, yield and ultimate strengths, improved with the addition of TiO 2 nanoparticles. Due to good bonding among the components, mechanical parameters such as microhardness and tensile strength were more than three times better than the Al matrix.