Hot Extrusion of a Commercial Aluminum Powder Metallurgy Metal Matrix Composite Material

Sintered preforms made of an aluminum powder metallurgy (PM) 2000 series metal matrix composite designed for press-and-sinter applications were forward extruded at 450 degrees C under displacement rates of 254 mm/min and 2,032 mm/min. The material was highly responsive to extrusion under these conditions and was readily formed into products that included 10-mm and 15-mm solid round bars as well as C-channel and round tubing profiles, wherein extrusion ratios ranged from 11:1 to 76:1. Significant metallurgical improvements were also observed in the seemingly defect-free products. These included gains in tensile yield strength (10 %), ultimate tensile strength (20 %), and tensile ductility (400 %) when compared to the nonextruded T6 counterpart. Such enhancements were attributed to the attenuation of full theoretical density, disruption of the residual oxide network, and the development of a partial duplex fiber texture with strong <111> and moderate <100> fiber components within the extruded PM products.