Precipitates in aged SiCw/AZ91 magnesium matrix composite

AZ91 magnesium alloy can be age hardened; continuous precipitation within the grain and discontinuous precipitation at grain boundaries occur competitively in this alloy, it is necessary to investigate the effect of reinforcement on the aging precipitation of SiCw/AZ91 magnesium matrix composites. The aim of this paper is to report this effect, with emphasis on the precipitate morphology and orientation relationships. In conclusion, there exist precipitates at the interface and precipitates in the grains of SiCw/AZ91 composites; precipitates form preferentially at the interface. The following orientation relationships can be obtained in the composites: (110)Mg sub 17 Al sub 12 //(0001)Mg, [113]Mg sub 17 Al sub 12 //[1100]Mg in the matrix, (110)Mg sub 17 Al sub 12 //(111)SiCw, [111]Mg sub 17 Al sub 12 //[011]SiCw at the interface.