Nano-sized SiC particles reinforced AZ91D composites were fabricated by ultrasonic method

and the friction and wear behavior of the as-cast composites under dry sliding condition were studied.The results indicate that compared with those of the AZ91D matrix

the composites exhibit higher hardness and wear resistance.Wear resistance of the composites is increased with the increase of volumetric fraction of SiC particles.The wear morphology of tested samples was examined with laser scanning microscope.It is found that main wear mechanim of the AZ91Dalloy is characterized by adhesive wear

while that of the composites is characterized by abrasive wear.It is supposed that the addition of nano-sized SiC particles results in the change of wear mechanism.