Mechanical properties enhancement of particle reinforced magnesium matrix composites used for hot extruded tubes

Abstract

This paper studies new magnesium metal matrix composites (Mg MMCs) reinforced with SiC particles by the stir-casting method for MMCs tubes hot extrusion. AZ61/SiCp MMCs' ingots reinforced with 0, 0.5 and 1 wt.% SiC particles are fabricated by the melt-stirring technique. AZ61/SiCp MMCs' tubes are manufactured by hot extrusion using a specially designed die-set. Obvious grain size refinement both by addition of particles and extrusion process are discovered. However, the grain refinement effect caused by extrusion process is much significant than that effect caused by SiC particle addition. The 0.2% yield strength (YS) of extruded tubes of AZ61 and AZ61/1 wt.% SiCp MMCs (without and with T5 treatment) are increased by 140.9-161.9% and 156.5-156.7%, respectively, compared with those of as-cast billets.