Nitridation Reactions in Magnesium Alloy Composites

Nitrogen reactions with aluminum in formation of AlN in molten magnesium alloys were investigated using chemical in situ molten metal process for the production of discontinuously reinforced Mg metal matrix composites (MgMMC). Effect of time on the formation of AlN nanoparticles in magnesium alloys with ammonia gas was studied. The samples were characterized using SEM-EDS, OM and XRD techniques. The results showed that the increase in time of the ammonia gas injection increased the aluminum nitride content of the alloy. At lower gas injection time, AlN particles were segregated and also engulfed by the freezing interface. But at higher gas injection time, the AlN particles formed were dispersed and distributed uniformly in the Magnesium alloy matrix. The industrial applications of this in situ production of AlN nanoparticle reinforced magnesium alloy matrix composites by molten metal technology are discussed.