Characterization of granular and polymer-embedded RDX grades: Floret tests

In an attempt to further contribute to the characterization of explosive compositions, small scale Floret tests were performed using four RDX grades, differing in product quality. A Floret test provides a measure - by indentation of a copper block - of detonation spreading or the initiability and shock wave divergence and is applied in particular to explosives used in initiation trains. Both as-received RDX and PBXs (based on the AFX-757 composition, a hard target penetrator explosive) containing these RDX grades were tested in the Floret test set-up. It was found that the Floret test method, when applied to granular, as-received RDX, was not able to discriminate between the overall RDX product qualities on the basis of the resulting volume of the indentation in the copper block. For the Floret test data of the PBX samples, a division into two parts, where one of the RDX lots shows a lower dent volume compared to the other RDX lots tested. Based on the results presented in this paper with granular RDX and a PBX composition and earlier results with a different type of PBX (based on PBXN-109, an insensitive high explosive used in a wide range of munitions), the Floret test could be developed into a screening test for shock sensitivity and product quality, without the need for complex and large volume casting of specific PBX compositions.