Mechanical characterization and strain-rate sensitivity measurement of Ti-7333 alloy based on nanoindentation and crystal plasticity modeling

The relationship between crystal orientations and meso-mechanical properties of β phase Ti-7333 titanium was investigated through the combination of nanoindentation experiments and simulation. The crystal plasticity finite element (CPFE) model for nanoindentation of single body-centered cubic crystal was established based on the experimental data. And the crystal plasticity constitutive law was implemented to simulate the nanoindentation process, obtaining satisfied results with an acceptable error. From the simulated pileup morphology patterns with different crystal orientations, it was found that the β phase experienced a symmetrical and orientation-related deformation process. Meanwhile, the strain-rate sensitivity (SRS) of β phase was investigated through nanoindentation tests based on continuous stiffness measurement (CSM) under different strain rates, varying between 0.2, 0.05 and 0.01 s−1. Two grains with different orientations exhibited similar SRS exponents, m, calculated from the experimental results. Keywords: Nanoindentation, Crystal plasticity, Rate sensitivity, Pileu