Abstract:
Multilayered Ti/Al/Nb composites were processed by the accumulative roll bonding (ARB) process using elemental foils of titanium, aluminum, and niobium. The rolled multilayered composites (MLCs) were prepared by ARB process up to two ARB cycles. The microstructure and texture evolution of the Ti, Al, and Nb in the MLCs were studied utilizing X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with electron backscattered diffraction (EBSD). The characterizations of crystallographic texture and microstructure were conducted using a creative approach; a layer by layer method on the rolling plane Texture evolution in the MLCs produced by symmetric rolling and asymmetric rolling was also studied in a layer by layer manner. In addition to studying the texture evolution of the Nb in the MLCs produced by the ARB process, the Bingham distribution was used to model the orientation distribution function (ODF) by employing MTEX, a quantitative texture analysis toolbox for Matlab®. This provided a bridge for the gap between experiments and Bingham modeling in terms of the crystallographic texture. As the numbers of ARB cycles increased, the microstructures tended to be heterogeneous through the thickness. Also, the texture development of the mating layers in the MLCs exhibited multiple texture domination rather than random. Furthermore, the developed textures of the layers in the MLCs during the ARB process were significantly different from that produced by conventional rolling. The characteristic textures formed in the MLCs subjected to the ARB process implied that the partial recrystallization and recovery occurred as a result of the adiabatic heat. The shear and compressive strain distributions were inhomogeneous through the thickness. Thus, the texture developments of the layers in the MLCs suggested a strong locational dependence. Where, the surface and the middle layers tended to form textures attributed to the shear, while, the transitory layers tended to form texture components induced by the compression.
