Tracking the evolution of materials microstructure : in situ mechanical testing with Novi CT rig
Why perform microtomography during tensile/compression tests with NOVI CT…
The use of microtomography during tensile/compression tests enables the impact of stresses on the microstructure of a sample to be visualised in 3D and in real time, so that macroscopic mechanical properties or morphological changes can be understood and then predicted.
3D visualisation of internal and external deformations. Observation and quantification of deformations in a material under stress, revealing how internal structures and microstructures react to applied loads.
Analysis of damage mechanisms. Studying damage mechanisms by identifying delaminations, defects at fibre/matrix interfaces, defects or cracks and their propagation, initiation of rupture at porosities or inclusions. This enables us to understand how and where the material begins to degrade.
Study of the evolution of microstructures. Examination of the microstructures and phases of heterogeneous materials, such as composites, certain metal alloys and biological materials, under different loading conditions.
Monitoring morphological changes. Real-time or regular monitoring of morphological changes in samples subjected to mechanical testing. This allows us to see how specific microscopic structural constituents, e.g. pores or inclusions, evolve.
Characterisation of local mechanical properties. Demonstration of links between changes in internal structure and local mechanical properties, helping to better understand the behaviour of materials at different scales.
Validation and improvement of models. Extraction of quantitative microstructural parameters for the validation of mechanical models: volume fractions, number of cracks, morphological parameters, orientation, etc.
Determination of crystalline phases. Enables the crystalline phases present in the material to be identified and the phase changes induced by mechanical stresses to be monitored. This is crucial for understanding how the different phases contribute to the overall mechanical properties.
Phase transformation analysis. Enables stress-induced phase transformations, such as the martensitic transformation in steels, to be monitored in real time or at regular intervals. These transformations can have a significant impact on the mechanical properties of the material.
Evaluation of anisotropic properties. X-ray diffraction can be used to assess the anisotropy of mechanical properties in materials, by correlating preferred crystallographic orientations with tensile/compression directions.
Study of dislocations and crystalline defects. Using X-ray diffraction, the presence of dislocations and other defects in the crystalline structure can be detected and analysed. Tensile/compression tests can induce the formation of new defects, the analysis of which is essential for understanding the hardening or softening mechanisms.
Texture characterisation. Texture analysis (the preferred orientation of crystalline grains) can be carried out using X-ray diffraction. Changes in texture due to deformation can reveal information about grain sliding and rotation mechanisms.
Why perform microtomography during tensile/compression tests with NOVI CT…
A recent study by Xploraytion, Novitom, Merck, and partners…