LAUSR

Abstract In this study, the effect of ceramic nanoparticles addition on the microstructure and texture of friction stir processed (FSP) copper has been investigated. For this purpose, two pure copper plates with and without Al2O3 nanoparticles were FSPed at rotational speed of 800 rpm and traverse speed of 100 mm min−1. Electron back scattered diffraction (EBSD) technique was employed in order to study the microstructure and texture of the fabricated samples. Based on the obtained results, considerable grain refinement by dynamic recrystallization (DRX) mechanism was observed in both specimens. However, Al2O3 inset led to evolution of ultrafine grained (UFG) structure with an average grain size of 0.7 µm. In addition, Al2O3 addition caused formation of lower twin boundaries and stronger texture components compared with the sample without ceramic reinforcements. The presence of nanoparticles increased the proportion of the continuous DRX mechanism (CDRX) compared to the discontinuous mechanism (DDRX) during grain structure formation.