THE EFFECT OF SIC WHISKERS ON THE HOT-DEFORMATION BEHAVIOR OF SICW AA2124 COMPOSITES/

The hot-deformation behavior of composites consisting of an AA2124 mat rix reinforced with 15 vol% of SIC whiskers has been studied over a te mperature range of 200 to 530 degrees C and a strain rate range of 1.3 2 x 10(-3) to 2.38 s(-1). Detailed analyses of flow curves and deforme d microstructures were made to identify the hot-recovery mechanism of the composites. The critical strain, epsilon(c), for dynamic recrystal lization of the composites was also evaluated by the work-hardening ra te, theta, and effective stress, sigma, from the flow curves. It was f ound that the hot-recovery mechanism of the composites was dynamic rec rystallization and the addition of SiC whiskers promoted nucleation of the dynamic recrystallization. The relationship between the critical strain, epsilon(c), and peak strain, epsilon(p), of the composites was epsilon(c) approximate to 0.52 epsilon(p). (C) 1997 Elsevier Science Limited.