ADC12-0.9 Yb alloy was fabricated by high-energy ultrasonic casting

and the effects of solution treatment on the microstructure and wear resistance of the alloy were investigated. The results indicate that the solution effect of ADC12-0.9 Yb alloy is desirable with the solution at 520 ℃ for 1 h

and the silicon phase is spheroidized to a greater extent without coarsening. Under the conditions of the load of 60 N

the speed of 100 r/min

and the friction time of 15 min

the wear mechanism of the as-cast ADC12 alloy is dominated by spalling wear

and that of the as-cast ADC12-0.9 Yb alloy is mainly abrasive wear

followed by plastic deformation and adhesive wear. The wear mechanism of ADC12-0.9 Yb alloy by solution treatment（solid solution at 520 ℃ for 1 h） is dominated by abrasive wear

accompanied with plastic deformation.