Multi-Axial Deformation Setup for Microscopic Testing of Sheet Metal to Fracture

Abstract

While the industrial interest in sheet metal with improved specific-properties led to the design of new alloys with complex microstructures, predicting their safe forming limits and understanding their microstructural deformation mechanisms remain as significant challenges largely due to the inadequacy of the existing experimental tools. The investigation of the strain-path dependent failure mechanisms requires miniaturized testing equipment, which can be placed in a scanning electron microscope for in situ experiments. So far, such tests could only be carried out for a single strain path (uniaxial tension). In this work, in order to fill this gap, a miniaturized Marciniak test setup is designed, built and tested. With this setup real-time, multi-axial tests of industrial sheet metal can be carried out to the point of fracture within a

Strain localization and damage in dual phase steels investigated by coupled in-situ deformation experiments and crystal plasticity simulations

“…The washer stabilizes the deformation of the sample and ensures failure in the central contact-free region deformed in biaxial tension. The details of the design and working principles of the setup are provided elsewhere (Tasan et al, 2012). This setup is placed into a FEI Quanta 600F SEM to carry out the deformation experiments.…”

A Small-Scale, Contactless, Pure Bending Device for In-situ Testing

“…In-situ SEM characterization of mechanical behavior of materials at the microscopic scale requires miniaturization of the testing device and adaptation to additional constraints, such as vacuum compatibility of all setup components, an increased influence of friction, and a horizontal working plane for the vertical SEM viewing direction. Sufficiently high load application can be challenging due to the limited space in a SEM vacuum chamber (e.g., 260 × 225 × 90 mm 3 for a FEI Quanta 600 SEM) [17], while the mitigation of friction can trigger unconventional design choices, such as electron discharge machined elastic hinges [13]. Ideally, the contactless, frictionless pure bending setup for large amplitude, cyclic loading, developed by Boers et al, should simply be miniaturized.…”

Intergranular Strain Evolution During Biaxial Loading: A Multiscale FE-FFT Approach

“…These complex strain paths, coupled with elastic/plastic anisotropy of polycrystals, result in heterogeneous distributions of intergranular strains, governing macroscopic response such as yield strength, work hardening, etc. Although biaxial testing is increasingly used to study macroscopic behavior of materials, [1][2][3] limited research efforts have been directed toward understanding the underlying microstructure and intergranular strain evolution. [4][5][6] In-situ neutron and synchrotron x-ray diffraction are well established techniques to study internal stress and microstructure evolution.…”