Mechanical, wear and corrosion behaviors of AZ91/SiC composite layer fabricated by friction stir vibration processing

Abstract

Abstract In this work, the effect of vibration on the mechanical, corrosion and wear characteristics of AZ91 composite layers fabricated by a modified friction stir processing has been examined. The vibration was implemented by the motor into the fixture placed beneath the work-piece. It was observed that vibration could highly modify the microstructure and mechanical properties of the composite layer owing to the increase in strain rate, deformation, and expansion of the material flow zone. Tensile strength increased from around 203 MPa for the samples processed by friction stir process (FSP) to about 234 MPa for the samples processed by friction stir vibration process (FSVP). Furthermore, a more uniform distribution of reinforcement SiC particles with less agglomerated domains was achieved using FSVP. The FSVPed sample exhibited better wear resistance compared to the conventional FSPed sample and the base metal. In this study, the principal common wear mechanisms were delamination, oxidation, abrasion, and plastic deformation. It was also found out that both FSPed and FSVPed specimens experienced lower hydrogen evolution volume during the immersion time compared to the base metal. Finally, the corrosion resistance of FSVPed sample highly increased compared to the FSP and base metal.