Abstract: Alumina and carbon short fibers reinforced ZL109 aluminum alloy hybrid composites are fabricated by preform squeeze-infiltrated route．The friction and wear properties of the hybrid composites at elevated temperature (≤400 ℃) are investigated．The results show that wear rate of the hybrid composites is less than that of ZL109 matrix and composites reinforced with only alumina or carbon fibre．The critical transition temperature from mild wear to severe wear of the hybrid composites was improved one time than that of monolithic ZL109 alloy because of mutual effect of alumina and carbon short fibers．The friction coefficient of the hybrid composites increases with the increase of alumina fiber volume fraction when test temperature is below the critical transition temperature．However，there exists critical value of alumina fiber volume fraction which influences wear property of the hybrid composites with the lowest wear rate at the volume fraction of 12%．The wear mechanisms of metal matrix and composites are ploughing groove and slight adhesion when test temperature is below the critical transition temperature．Whereas the wear mechanisms of matrix and composites will be shifted to severe adhesion with the increase of test temperature and beyond transition temperature.

Key words: Elevated temperature friction and wear, Metal matrix hybrid composites, Wear mechanism