Dynamic fragmentation of cellular, ice-templated alumina scaffolds
Abstract
We examine the dynamic failure of ice-templated freeze-cast alumina scaffolds that are being considered as biomimetic hierarchical structures. Three porosities of alumina freeze-cast structures were fabricated, and a systematic variation in microstructural properties such as lamellar width and thickness was observed with changing porosity. Dynamic impact tests were performed in a light-gas gun to examine the failure properties of these materials under high strain-rate loading. Nearly complete delamination was observed following impact, along with characteristic cracking across the lamellar width. Average fragment size decreases with increasing porosity, and a theoretical model was developed to explain this behavior based on microstructural changes. Using an energy balance between kinetic, strain, and surface energies within a single lamella, we are able to accurately predict the characteristic fragment size using only standard material properties of bulk alumina.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 08, 2016
- Source ID
- 10.1063/1.4939702
Entities
People
- John D. Molitoris
- Joseph P Hooper
- Octavio Cervantes
- Seanwoo Nam
- Yi Ming Tan
Organizations
- Defense Threat Reduction Agency
- Lawrence Livermore National Laboratory
- Naval Postgraduate School