The effect of friction stir processing on mechanical, wear and corrosion characteristics of Cu-AlN-BN surface composite.

This research investigates the impact of hybrid particles dispersed onto the surface of a copper matrix using Friction Stir Processing (FSP) on its microstructural, mechanical, and corrosion behavior. The hybrid particles under study consist of equal fractions of Aluminium Nitride (AlN) and Boron Nitride (BN). Microstructural characterization confirms breakdown of grain size due to dynamic recrystallization and presence of particles, along with their effective bonding to copper matrix. Attained results indicated a significant enhancement in hardness, with an increase of up to 3.9 % upon the introduction of particles onto the surface. Moreover, the tensile properties exhibit noticeable improvements in terms of ultimate tensile strength (6.39 %) and yield strength (6.12 %), albeit at the expense of reduced ductility in the copper matrix. Furthermore, the wear rate (decreases up to 22 %) and corrosion rate of the developed composites demonstrate a decreasing trend with the introduction of particles. This improvement can be attributed to the reduction in grain size during the FSP process and the formation of a nitride passive layer facilitated by the reinforced hybrid particles, thereby effectively inhibiting the corrosion rate.