Textural and microstructural gradient effects on the mechanical behavior of a tantalum plate

The effects of gradients in the texture and microstructure of a tantalum plate on mechanical behavior are examined. In particular, the effects of variations in grain size and texture from the surface of the plate to the centerline on the yield behavior and final shape of compression samples are investigated. Individual lattice orientations were measured on samples both before and after deformation using automatic analysis of electron backscatter diffraction patterns. These data were used as input to a polycrystal plasticity model based on the Taylor assumption of uniform strain. Results are compared from experimental and simulated 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 nonuniform plastic response of the material. This work also demonstrates the capability of currently available tools for characterizing inhomogeneous microstructures and modeling the effects of variations in texture and microstructure on mechanical behavior.