TEXTURAL AND MICROSTRUCTURAL GRADIENT EFFECTS ON THE MECHANICAL-BEHAVIOR OF A TANTALUM PLATE

The effects of gradients in the texture and microstructure of a tantal um plate on mechanical behavior are examined. In particular, the effec ts of variations in grain size and texture from the surface of the pla te to the centerline on the yield behavior and final shape of compress ion samples are investigated. Individual lattice orientations were mea sured on samples both before and after deformation using automatic ana lysis of electron backscatter diffraction patterns. These data were us ed as input to a polycrystal plasticity model based on the Taylor assu mption of uniform strain. Results are compared from experimental and s imulated compression tests. The effects of the texture and grain size gradients on these results are discussed. The influence of the texture gradient was found to be the dominating factor controlling the nonuni form plastic response of the material. This work also demonstrates the capability of currently available tools for characterizing inhomogene ous microstructures and modeling the effects of variations in texture and microstructure on mechanical behavior.