Development of quartz particulate reinforced AA6063 aluminum matrix composites via friction stir processing

Friction stir processing (FSP) has been accepted as a potential method to produce aluminum matrix composites (AMCs) without the drawbacks of liquid metallurgy methods. The present work focuses on the development of AMCs reinforced with quartz (SiO2) particles using FSP. Grooves with various dimensions were machined on AA6063 plates and compacted with quartz particles. A single pass FSP was carried out using a combination of optimized process parameters. The volume fraction of quartz particles in the AMCs was varied from 0 to 18 vol.% in steps of 6 vol.%. The developed AA6063/Quartz AMCs were characterized using optical, scanning and transmission electron microscopy. The quartz particles were distributed uniformly in the aluminum matrix irrespective of the location within the stir zone. The grains of the AA6063 were extensively refined by the combination of thermomechanical effect of FSP and the pinning effect of quartz particles. The dispersion of the quartz particles improved the microhardness and wear resistance of the AMCs. The role of quartz particles on the worn surface and wear debris is reported.