Wear properties of Al–Al ₂ O ₃ /TiB ₂ surface hybrid composite layer prepared by friction stir process

Abstract

In this study, surface hybrid composite was fabricated on Al6061 base sheets using friction stir processing (FSP). Samples were subjected to various numbers of FSP passes from one to four with Al 2 O 3 /TiB 2 powder. Influence of number of FSP passes was studied on distribution of Al 2 O 3 /TiB 2 particles in aluminium matrix, microstructure, hardness, and wear properties of specimens. The results showed that increase in the number of passes causes a more uniform dispersion of composite particles and thus, decreases particles clustering. In addition, an increase in the number of FSP passes was found to decrease the matrix grain size of the surface hybrid composite. It was observed that the hardness increased as the number of passes increased due to presence and pinning effect of hard Al 2 O 3 /TiB 2 particles. Also, at higher number of passes, the surface hybrid composite wear resistance was increased.