Characteristics of two Al based functionally gradientcomposites reinforced by primary Si particles and Si/in situ Mg₂Si particles in centrifugal casting

来源期刊：中国有色金属学报(英文版)2010年第3期

论文作者：翟彦博 刘昌明 王开 邹茂华 谢勇

文章页码：361 - 370

Key words：centrifugal casting; functionally gradient composites; in situ primary Si particles; in situ Mg₂Si particles

Abstract: Two kinds of Al based functionally gradient composite tubes reinforced by primary Si particles alone and primary Si/ in situ Mg₂Si particles jointly were successfully prepared by centrifugal casting, and their structural and mechanical characters were compared. It is found that the composite reinforced with primary Si particles takes a characteristic of particles distribution both in the inner and outer layers. However, composite reinforced with primary Si/Mg₂Si particles jointly takes a characteristic of particles distribution only in the inner layer and shows a sudden change of particles distribution across the section of inner and outer layers. The hardness and wear resistance of Al-19Si-5Mg tube in the inner layer are greatly higher than that in the other layers of Al-19Si-5Mg tube and Al-19Si tube. Theoretical analysis reveals that the existence of Mg₂Si particles is the key factor to form this sudden change of gradient distribution of two kinds of particles. Because Mg₂Si particles with a lower density have a higher centripetal moving velocity than primary Si particles, in a field of centrifugal force, they would collide with primary Si particles and then impel the later to move together forward to the inner layer of the tube.

基金信息：the Natural Science Foundation of Chongqing City, China