Effect of agro waste ash as reinforcement on microstructure and mechanical properties of aluminium surface composite fabricated via FSP technique

Abstract

The life span of AA6061 components in many applications depends on surface properties. Therefore, it is advantageous to reinforce the surface layer while the bulk material retains its ductility and toughness. Non-deformable nature of ceramic reinforcement particles in AMCs poses loss in ductility and toughness of the composite. Rice husk ash (RHA) is an agro-industrial waste and by product of rice husk. Friction stir processing FSP is an evolving novel process used to fabricate surface metal matrix composites. AA6061/RHA surface composite was produced using friction stir processing (FSP). Optical and scanning electron microscopy, micro hardness and tensile tests were used to characterize the specimens. The results indicated that uniform distribution of RHA particles in the stir zone SZ by FSP process can improve the micro hardness of specimens. The micro hardness of the AA6061 aluminium matrix beside the FSP zone, the stir zone of specimen processed by the FSP without RHA particles, and the stir zone of specimens processed with RHA using (one, two, and four FSP passes), were about: 66HV, 46.6HV, 106HV, 99HV, and 86HV, respectively. Higher hardness value of 106HV was achieved with the Sample processed using one pass FSP. RHA shows encouraging positive potential for further study as reinforcement for the fabrication of low cost high performance surface composite.