Development of 40 vol. and 20 vol. (AlN+Mg_2Si)/Mg Matrix Composites

摘要

Composites of fine AlN particles in magnesium matrix have been successfully in-siturnsynthesized using pure Al, Si3N4 and Mg as raw materials. Microstructures containing 40 vol. %rnand 20 vol. % (AlN+Mg_2Si)/Mg were obtained by heating to 770 ℃ and 850 ℃ respectively forrnone hour under a protective gas atmosphere. The microstructures were characterized using X-rayrndiffraction, optical microscopy and consisted of fine AlN particles embedded in the prior Si3N4rnagglomerates and faceted Mg_2Si phases within the magnesium matrix. The Scheil solidificationrnpaths were calculated and compared. The volume fraction and size of Mg_2Si phase were reducedrnby decreasing silicon concentration and increasing the reaction temperature.