The influence of morphology on the low- and high-strain-rate compaction response of CeO2 powders

• Published in: Journal of applied physics 2014-03, Vol.115 (12)
• Main Authors: Fredenburg, D. A., Koller, D. D., Coe, Joshua D., Kiyanda, C. B.
• Format: Article
• Language: English
• Subjects: Applied physics; Cerium oxides; Compressibility; Compression tests; Equations of state; Morphology; Strain rate; Stresses
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4868356

The low- and high-strain-rate compaction response of three distinct morphology CeO2 powders was measured experimentally. At low-strain-rates, the compression path was found to vary with initial particle morphology as a result of differences in initial packing structure and particle rearrangement at low stresses. However, similar compression responses were observed at higher stresses under low-strain-rate loading. Dynamic experiments were performed at impact velocities between 0.15 and 0.78 km/s, and resulted in compaction stresses of 0.51-4.59 GPa in the powders. In contrast to the behavior observed at low stresses and low-strain-rates, dynamic loading resulted in a similar compaction response for all morphology powders. The dynamic results were treated with a Hayes equation of state augmented with a P-α compaction model, and good agreement between experimental and theoretical results was achieved. From the observed similarities in compressibility for the three morphology powders at elevated stresses at both low- and high-strain-rates, a relationship is proposed linking the measured strength properties at low-strain-rates to those controlling the compaction response under dynamic loading.