The Mechanical Response of Aluminum Nitride at Very High Strain Rates

In previous work, we have used a modified compression Kolsky bar to determine the dynamic compressive strength of some ceramic materials, including aluminum nitride (AlN), at strain rates of approximately 10

3

s

–1

. However, there is very limited experimental work on ceramics at higher strain rates (of the order of 10

4

s

–1

) because of various technical difficulties. This work seeks to characterize the mechanical properties of AlN within the strain rate range (10

3

~10

4

s

–1

) using the desktop Kolsky bar (DKB), taking advantage of the benefits of miniaturization. Our interest is in the influence of the loading rate on the compressive strength under uniaxial stress conditions. Microstructural analysis is performed to identify the failure mechanisms at different strain rates.