Bend Deformation Behavior of Silicon Carbide Reticulated Porous Ceramics
This work will report the deformation behavior of silicon carbide reticulated porous ceramics (SiC RPCs) under three-point bend test. SiC RPCs were fabricated by replication processing using an open-cell polyurethane sponge with cell size of ~ 13 pores per inch (ppi). It is shown that the deformation behavior strongly depends on the loading uniformity and the macrostructure. Using a compliant layer (0.5 mm paper pad), the uniform loading leads to a significant transition in the load-displacement curve of RPCs from the complex saw-tooth shape to the one similar to dense ceramics, despite the presence of some macrostructural flaws and partial clogged cells. However, this dependence of loading uniformity is alleviated by developing highly uniform macrostructure with fewer flaws and clogged pores. Even, this dependence becomes less important as the struts become thicker and stronger, leading to an increase in relative density, accordingly. The bend result of RPCs with highly uniform macrostructure is in excellent agreement with the GA (Gibson and Ashby) model, but the one with un-uniform macrostructure deviates from the GA model. This work shows that the macrostructure plays an important role in deformation behavior of RPCs under bend.
Duk Yong Yoon, Suk-Joong L. Kang, Kwang Yong Eun and Yong-Seog Kim
X. W. Zhu et al., "Bend Deformation Behavior of Silicon Carbide Reticulated Porous Ceramics", Materials Science Forum, Vols. 534-536, pp. 941-944, 2007