Effect of nanoparticles on metal matrix composites fabricated by ultrasonic stir casting
Husain Mehdi, Shallender Singh Bhati, Pradeep Kumar Mouria, Subhash Mishra, Mandeep Bhadana, Lalit Batra
Abstract
In this work, the metallurgical and mechanical properties of AA6082 aluminium alloy reinforced with different weight percentages of SiC and TiO2 (2%, 4%, 6%, and 8%) was analysed. AA6082 (6 vol.% SiC + 4 vol. % TiO2) composite exhibited increases in the maximum UTS of 19.98%, and hardness of 19.21%, while maximum hardness increases of 28.71% for MMC_S4 (8 vol.% SiC + 2 vol. % TiO2). Microhardness measurements revealed a linear improvement with rising TiO2 content, peaking at 125.5 hV in the AA6082/8 wt% SiC/2 wt% TiO2 composite – a 28.71% increase compared to the base alloy. This increase was attributed to the hardness of nanoparticles and grain refinement. Microstructural analysis showed significant grain refinement as the SiC and TiO2 content increased, with the 6% SiC and 4% TiO2 composite displaying the finest grain size. However, higher TiO2 concentrations presented difficulties in achieving uniform nanoparticle dispersion, leading to clustering and porosity.