Lhuissier Pierre, Bormann Therese, Pelloux Guillaume, Bataillon Xavier, Pelloux Franck, Josserond Charles, Gravier Pauline, Blandin Jean Jacques, Boller Elodie, Salvo Luc
Université Grenoble Alpes, CNRS, Grenoble INP, SIMAP, F-38000 Grenoble, France.
ID19 Beamline, ESRF, 6 rue Jules Horowitz, BP 220, 38043 Grenoble Cedex 9, France.
J Synchrotron Radiat. 2021 Mar 1;28(Pt 2):530-537. doi: 10.1107/S1600577521001107. Epub 2021 Feb 9.
Metallic materials processing such as rolling, extrusion or forging often involves high-temperature deformation. Usually under such conditions the samples are characterized post mortem, under pseudo in situ conditions with interrupted tests, or in situ with a limited strain rate. A full in situ 3D characterization, directly during high-temperature deformation with a prescribed strain-rate scheme, requires a dedicated sample environment and a dedicated image-analysis workflow. A specific sample environment has been developed to enable highly controlled (temperature and strain rate) high-temperature deformation mechanical testing to be conducted while performing in situ tomography on a synchrotron beamline. A dedicated digital volume correlation algorithm is used to estimate the strain field and track pores while the material endures large deformations. The algorithm is particularly suitable for materials with few internal features when the deformation steps between two images are large. An example of an application is provided: a high-temperature compression test on a porous aluminium alloy with individual pore tracking with a specific strain-rate scheme representative of rolling conditions.
金属材料加工，如轧制、挤压或锻造，通常涉及高温变形。通常在这种条件下，样品是在事后、在中断试验的伪原位条件下或在有限应变速率的原位条件下进行表征的。在规定应变速率方案下，在高温变形过程中直接进行完整的原位三维表征，需要专门的样品环境和专门的图像分析工作流程。已经开发了一种特定的样品环境，以便在同步加速器光束线上进行原位断层扫描时，能够进行高度可控（温度和应变速率）的高温变形力学测试。当材料承受大变形时，使用一种专门的数字体积相关算法来估计应变场并跟踪孔隙。当两个图像之间的变形步长较大时，该算法特别适用于内部特征较少的材料。给出了一个应用示例：对一种多孔铝合金进行高温压缩试验，采用代表轧制条件的特定应变速率方案对单个孔隙进行跟踪。
