Role of Microstructure on Impact Response and Damage Morphology of Ice-Templated Porous Ceramics
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RESEARCH PAPER
Role of Microstructure on Impact Response and Damage Morphology of Ice‑Templated Porous Ceramics S. Akurati1 · D. A. Terrones1 · D. Ghosh1 Received: 31 May 2020 / Accepted: 13 September 2020 © Society for Experimental Mechanics, Inc 2020
Abstract The central focus of this study is to investigate the influence of microstructure and direction of impact (relative to the growth direction of ice crystals) on the impact behavior of ice-templated sintered alumina materials and understand the relationship between dynamic compressive strength and impact response. All materials were fabricated using alumina suspensions of the same solid loading but at three different freezing front velocity (FFV) regimes; very-high FFV, moderately-high FFV, and low FFV. Lamella wall thickness, pore size, and pore aspect ratio decreased, and wall connectivity increased with FFV. Materials also exhibited a structural gradient along the growth direction of ice crystals. As the templated microstructure became finer with FFV, the impact resistance of the materials increased, and radius of damage crater, depth-of-penetration, and mass loss decreased. Materials also exhibited radial cracking, and the materials fabricated at very-high FFV showed a greater propensity for radial cracking for impact along the growth direction. The impact process evolved in three phases; penetration phase, dwell phase and rebound phase. Analysis of high-speed videos revealed that modifying the microstructure affected not only the impact resistance but also the duration of these phases. Variation in microstructure caused a change in the mechanism of damage evolution during impact. Dynamic compressive strength increased with FFV, and the results revealed a direct relationship between impact response and strength. For both impact and dynamic compression, energy absorption per unit volume increased with FFV, further reinforcing the relationship between impact behavior and the dynamic compressive response of ice-templated materials. Keywords Ice-templating · Microstructure · Sphere impact · High-speed imaging · Damage · SHPB
Introduction Impact events, where a stationary object and a flying object or two flying objects interact, are routinely encountered in various applications, ranging from aerospace to military. In these events, materials and structures are subjected to inelastic deformation and failure under high rate loading conditions [1–7]. Understanding the deformation behavior of materials during the projectile–target interactions and the correlation between mechanical properties and impact Electronic supplementary material The online version of this article (https://doi.org/10.1007/s40870-020-00272-6) contains supplementary material, which is available to authorized users. * D. Ghosh [email protected] 1
Department of Mechanical and Aerospace Engineering, Old Dominion University, Norfolk, VA 23529, USA
performance of materials is of profound fundamental interest. The complexity of impact behavior of materials stems from that the projectile–ta
