Abstract
Confined deformation, e.g. mechanical twinning, shear banding, and Lüders banding, etc. was extensively observed in metals and alloys with low stacking-fault energies, especially under complex loadings, governing the mechanical properties. It is often accompanied with gradient microstructures to accommodate the stress concentrations. Understanding the micromechanical behaviors of structural materials having confined deformation is important for evaluating the structural stabilities of engineering components. Synchrotron-based techniques provide powerful tools for multiscale microstructural characterization owing to their good resolution in real/reciprocal space, fast data collection/processing and flexible application scenarios. In this paper, the synchrotron-based high-energy X-ray diffraction (HE-XRD) and microdiffraction (μXRD) techniques in combination with traditional characterization methods are used to reveal the deformational gradient structures/stresses under different loading modes in multiscale. The structure/stress gradients induced by laser shot peening treatment and the deformation twins generated during uniaxial tensile loading in pure titanium were systematically studied by HE-XRD and μXRD, in order to elucidate the accommodating role of the deformational structures subjected to various confined scenarios. The new finding regarding the micromechanical behaviors related to confined deformation contributes to the in-depth understanding of related complex deformation behaviors.
Highlights
The strain localization in metallic materials is mainly governed by both confined deformation geometry and crystallographic features [1]
The further deformation is constrained by the above-mentioned banding structures, causing alteration of micromechanical behavior, which is here referred as the confined deformation
The absorbent material immediately vaporizes and forms plasma with high temperature and high pressure moving towards the confined layer
Summary
The strain localization in metallic materials is mainly governed by both confined deformation geometry and crystallographic features [1]. The plastic deformation heterogeneity is enhanced by the complex interactions of dislocation slip and mechanical twinning, generating the local hardening/softening due to crystal anisotropy and change in deformation path, especially in low stacking-fault energy metals and alloys. These samples undergoing a dense shear strain may produce banding structures (e.g. shear bands) with a jump in both grain orientation and stress, having the specific substructure patterns clearly distinguished from the surrounding matrix. The origin of mechanical heterogeneity as a complex irreversible change in substructures under various loading conditions is usually involved with the formation of various zones with localized strains, e.g. twinning, shear banding, and Lüders banding, etc. The micron-scale inhomogeneous stress field significantly influences the microstructure under further loading
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
