Real-time visualization of impact damage in monolithic silicon carbide and fibrous silicon carbide ceramic composite

In situ characterization of foreign object damage (FOD) in environmental‐barrier‐coated silicon carbide (SiC) ceramic

“…In contrast, the PSZ sphere appears to pulverize the topcoat due to its high impact energy ‡ , and erode the bond coat as it simultaneously deforms and fragments on top of it. A similar response has been observed previously in fibrous SiC ceramic composites where, a higher degree of fracture is observed for FOD by the Si 3 N 4 sphere and more pulverization for the PSZ sphere [30].…”

“…Spheres of Partially Stabilized Zirconia (MSE Supplies, Tucson, AZ) and Silicon Nitride (Coors Tek, Golden, CO), with nominal dimeters of 1.5 mm, were used as projectiles for the FOD experiments. Details of the microstructures and properties for these materials have been documented in a previous study [30]. The PSZ spheres were shown to retain patches of large internal porosities which expose unsintered particles that compose the overall structure.…”

“…This is achieved through a novel characterization method whereby a polychromatic X-ray beam from a synchrotron source is used to peer through and image the coated substrate as it is impacted by a spherical projectile. In a preliminary study, FOD of uncoated SiC targets was successfully visualized at a resolution of 0.5 µs [30]. Here, an APS bilayer coating consisting of a Mullite topcoat and a Silicon bond coat is applied to the SiC substrate.…”

“…A detailed description of the combined light-gas gun and in situ dynamic X-ray imaging facility can be found elsewhere [30,33]. Only a brief overview is offered here.…”

“…As noted in the introduction section, the FOD behavior of uncoated SiC has been previously investigated using the same in situ dynamic X-ray characterization method [30]. Irrespective of the projectile material, a purely brittle elastic response was observed with primary Hertzian cone cracks and secondary median cracks.…”