Evaluation of microstructure and tribological behavior of FS-processed Al/SiC-BNh hybrid composite on the Al-1050 substrate

Abstract

In this research, in order to improve the wearing property Al-1050 the Al/(SiC+BNh) hybrid composite was synthesized via friction stir processing (FSP) on the Al-1050 substrate and its tribological behavior was compared with FS-processed Al/SiC and Al/BNh mono surface composite layers. Microstructural studied revealed dynamic recrystallization caused significant grain refinement in the stir zone (SZ) i.e., considerable reduction of SZ grain size in comparison to base metal. Increasing of FSP pass numbers from 3 to 5 passes resulted in increasing of SZ hardness and reduction of SZ grain size from 11 ± 2 µm to 6 ± 1 µm. Wearing tests indicated that hybrid Al/(SiC+BNh) composite has a higher wear resistance than Al/SiC and Al/BNh layers. The reduction of wear rate was in the following order: base metal (0.075 mg/m), FS-processed Al/SiC (0.047 mg/m), FS-processed Al/BNh (0.046 mg/m) and FS-processed Al/SiC+BNh (0.039 mg/m).