Mechanical Properties of Friction Stir Processed 1100 Aluminum Reinforced with Rice Husk Ash Silica at Different Rotational Speeds

This paper presents a study on friction stir processed 1100 aluminum withincorporation of rice huskash derived, amorphous silica particles and fabricated at different tool rotational speeds. During friction stirring amorphous silica powder was placed into a groove made in the joining line of Al 1100 plates. Friction stirringwas performed with clockwise tool rotational speeds of 600 rpm, 865 rpm, 1140 rpm or 1500 rpm with a constant 45 mm/min travelling speed and a 2° tilt angle. High rotational speed (1140 rpm) facilitated material flow in the stir zone, contributing to fine aluminum matrix grain size (30- 10μm) as a result of dynamic recrystallization. Stirring at this rotational speed also caused the fracturingrelated refinement of silica particles to 10μm particle sizethat isassociated with good distribution in the aluminum matrix. Reduction in wear rate of friction stir processed Al1100 with improved hardness was believed to be due to the presence of hard silicawith high interfacial strength and high hardness of recrystallized aluminum grains in the stir zone.