Properties of submicron AlN particulate reinforced aluminum matrix composite

Two kinds of mixed powders (Al + AlN) were obtained by mechanical mixing with dry milling and wet milling in present study. X-ray and SEM analysis show that dispersant agent (acetone) could not only prevent the aluminum powders from being oxidized, but also impede the conglobation of submicron AlN particles during the wet-method mechanical mixing. AlN/Al composite could be fabricated successfully by means of a combined method of wet mixing, cold isostatic pressing and hot extrusion. The tensile strength and thermal-expansion coefficient of the composite has been compared with pure aluminum.