The spall strength of alumina ceramics

Abstract

The response to plate impact loading of three aluminas with varying glass content and porosity has been investigated. Spall strengths have been shown to be dependent on the amplitude and duration of the compression pulse which precedes the tensile loading, but insensitive to the rate of release. Some tensile strength is measured in impacts where the Hugoniot elastic limit has been exceeded. The effect of the material microstructure on the dynamic tensile strength has also been studied. Low porosity aluminas with many microstructural irregularities were found to possess the lowest spall strengths. Experimental values compare well with those predicted by an energy balance theory developed by Grady [J. Mech. Phys. Solids 36, 353 (1988)]. © 1998 American Institute of Physics.