Multifractal-based assessment of Gilsocarbon graphite microstructures

In situ observation of compression damage in a 3D needled-punched carbon fiber-silicon carbide ceramic matrix composite

“…Studies during mechanical testing, some at elevated temperatures, have provided insights into damage development in a wide range of materials, including metals [13], metal matrix composites [14,15], polygranular graphite [16], gypsum [17] and ceramic matrix composites [18,19]. Digital Volume Correlation (DVC) measures the relative deformations between successive tomographs, using contrast from the heterogeneities in the microstructure (e.g.…”

Porosity analysis of superfine-grain graphite IG-110 and ultrafine-grain graphite T220

“…The gas-escape pores of pristine and oxidized nuclear graphite have been characterized by using mercury porosimetry [6,9], X-ray tomography [10][11][12][13][14], focus ion beam serial milling [15,16] and optical microscopy [17][18][19][20]. There is a difference in pore size distributions obtained from different techniques.…”

4D synchrotron X-ray microtomography of fracture in nuclear graphite after neutron irradiation and radiolytic oxidation

“…6(ab) confirm that cracks in both the unirradiated and irradiated Gilsocarbon specimens studied extend along deflected paths. This is perhaps to be expected as crack deflection in graphite is predominately governed by the distribution of filler particles throughout the graphite matrix [10,15] and the continued existence of a weak filler-binder interface [10,32]. As illustrated in Fig.…”

“…13(l), the former is largely unaffected by neutron irradiation and radiolytic oxidation. This has been observed to much higher weight losses in both thermally and radiolytically-oxidised nuclear graphite [15,53,54]. Meanwhile, the latter is only amplified by the irradiation-induced "hardening", which both strengthens and stiffens the filler particles of the graphite, and preferential radiolytic oxidation of the binder phase [54], that simultaneously weakens the graphite matrix (irradparticle σ = 652 MPa, E = 37.5 GPa vs. irradmatrix σ = 357 MPa, E = 8.6 GPa [46]).…”

“…X-ray computed tomography (XCT) has been shown to be a powerful tool for performing in situ observations of deformation and fracture processes in materials. In recent years, this technique has been used in multiple studies to provide an in-depth analysis of the different microstructural mechanisms that govern strength and fracture in unirradiated nuclear graphite [9][10][11][12][13][14][15][16][17]. These properties are of particular interest because of their direct relationship with component reliability and service lifetime.…”