Microstructure, texture, and mechanical properties correlation of AA5083/AA6061/SiC composite fabricated by FSAM process

Abstract

The current study deals with the effect of silicon carbide (SiC) particle reinforcement on the microstructure, texture evolution, and mechanical properties of the AA5083-O/AA6061-T6 build fabricated using the friction stir additive manufacturing (FSAM) process. The stir zone (SZ) of particle reinforced build shows ultra-fine grain refinement (av. size of 4.22 μm) in comparison to AA5083 (41 μm) and AA6061 (43 μm) base metals. The extent of grain refinement is possible due to the uniform dispersion of SiC particles in the matrix accompanied by dynamic recrystallization (DRX) driven by particle-stimulated nucleation (PSN) and the Zener-Holloman mechanism. Weak texture intensities were visible for both reinforced/unreinforced cases due to reheating and re-stirring action at the joint interface. Major shear texture components (B/ B‾, and C) with the presence of recrystallization texture components cube {001} <101>, P {011} <112>, rotated cube (H) {001} <110> and F {111} <112> were noted in SiC reinforced build, suggesting the DRX at the joint interface. SZ of SiC reinforced build consists of an average microhardness of 116 ±4HV0.1 which is 1.2 times higher than the average microhardness of unreinforced build (96 ±3HV0.1). The maximum strength of 291 MPa was noted for AA5083/AA6061/SiC composite, which is appreciably higher than the unreinforced case (197 MPa).