In situ observation of mechanical damage within a SiC-SiC ceramic matrix composite

Abstract

SiC-SiC ceramic matrix composites are candidate materials for fuel cladding in Generation IV nuclear fission reactors and as accident tolerant fuel clad in current generation plant. Experimental methods are needed that can detect and quantify the development of mechanical damage, to support modelling and qualification tests for these critical components. In situ observations of damage development have been obtained of tensile and C-ring mechanical test specimens of a braided nuclear grade SiC-SiC ceramic composite tube, using a combination of ex situ and in situ computed X-ray tomography observation and digital volume correlation analysis. The gradual development of damage by matrix cracking and also the influence of non-uniform loading are examined

X-ray tomography of additive-manufactured zirconia: Processing defects – Strength relations

“…Particular interest has been recently shown for the application of XCT in the field of AM, to evaluate AM methods, to control the geometry of the produced components or to characterize their microstructure [33][34][35][36][37]. In the field of ceramic materials, XCT have been particularly used for structural or damage characterization of ceramic matrix composites [38][39][40][41][42][43] and to evaluate pore morphology and interconnectivity of porous or cellular ceramics [44][45][46][47][48][49][50]. XCT analysis was also applied to follow the microstructural evolutions during the compaction process of [51] or their sintering [52][53][54], and to investigate indentation induced cracking in dense alumina [55].…”

Synchrotron X-ray characterization of crack strain fields in polygranular graphite

“…These can be performed with either laboratory or synchrotron facilities; the latter offers faster rates for in situ studies due to the brilliance of the X-rays. Digital volume correlation (DVC) [54] can map the relative changes in the displacement field between tomographic datasets, allowing quantitative observations of three-dimensional deformation [53,55,56]. In high quality tomographs of suitable microstructures, for which the internal features provide the necessary "speckle" contrast, the displacement measurement precision is sub-voxel, 1 and both elastic and plastic deformations may be studied.…”

In Situ Diagnostics of Damage Accumulation in Ni-Based Superalloys Using High-Temperature Computed Tomography

“…This is versatile compared with other reported works-for example, a maximum load of 2 kN at temperatures up to 1750°C [35] or 5 kN tensile loading capacity with the temperature limited to 250°C. [36] The devised in situ XCT system is applicable to a much Fig. 18-Ex situ and in situ XCT sliced images of a fractured sample (Inconel 718, 10 À2 s À1 ).…”