Mechanical Responses of Primary-α Ti Grains in Polycrystalline Samples: Part II - Bayesian Estimation of Crystal-Level Elastic-Plastic Mechanical Properties from Spherical Indentation Measurements

Abstract

In the second part of the work, a two-step Bayesian framework is utilized for the estimation of values of the single crystal elastic constants as well as the initial slip resistances of the different slip families in the primary α-phase components in the Ti alloys of different compositions. These estimations are based on the spherical indentation measurements presented in part I of this series. The first step of the two-step Bayesian framework established a reduced-order model which captures the dependence of the indentation property as a function of the relevant crystal-level (intrinsic) material properties and the crystallographic lattice orientation in the indentation deformation zone. This reduced-order model is calibrated to high-fidelity results obtained from suitable crystal-plasticity finite element (CPFE) simulations. The second step involved the calibration of the indentation measurements obtained within the primary α-phase (from part I of this series) to the reduced-order model established in the first step. It is demonstrated that the protocols described above result in the successful generation of a comprehensive dataset of single crystal elastic-plastic properties across a collection of Ti alloys while accounting for the implicit uncertainties in the spherical indentation measurements.