Improvement of wearing property of Al/ (SiC+BNh) surface hybrid composite fabricated by friction stir processing

In this study, the microstructural and tribological properties of surface Al/(SiCӘ) hybrid composite was investigated. Al/(SiCӘ) hybrid composite was produced on the surface of Al-1050 substrate via friction stir processing to achieve simultaneous high hardness of SiC particle and lubricating property of BNh particles. Microstructural studied revealed that grain refinement and significant reduction of grain size occurred in the stirred zone. Micro hardness evaluation illustrated that friction stir processing (FSP) increased hardness of stirred zone to about 60± 5HV that was 70% more than the hardness of base metal. Wearing and corrosion properties of Al/(SiCӘ) hybrid composite were investigated and compared with those of base metal, friction stir processed, Al/SiC and Al/BNh surface composite. Evaluation of wearing property indicated that the wear rate of base metal, Al/SiC surface composite, Al/BNh surface composite and Al/(SiCӘ) surface composite were 0.075, 0.047, 0.046 and 0.039mg/m, respectively which indicated the highest wearing resistance of Al/(SiCӘ) in comparison to the base metal and mono SiC or BNh surface composite. This could be related to the simultaneous increase of hardness and reduction in the friction coefficient of hybrid surface composite. . Investigations of corrosion properties showed that FSP improved the corrosion resistance of base metal more than 30%.