L-119 A review of fuze booster compositions for use in IM applications
The most effective method for achieving successful Insensitive Munition (IM) design is to use a systems approach. The three key elements in the IM systems approach are:
- The choice of the energetic materials (EMs)
- The mitigation technologies and design tradeoffs integrated in the design of the case and more generally in the non-explosive parts of the munition.
- The mitigation technologies and design tradeoffs integrated in the design of the packaging
This document will focus on the choice of the EMs for fuze booster application. Information concerning the mitigation technologies and design tradeoffs integrated in the design of the case and/or in the design of the packaging (Storage and transport issues) can be found in chapter 4 of the document MSIAC L-101 entitled Report on the state of the art IM design technology (2003).
The development of insensitive booster compositions is a critical issue for any munition programme seeking IM compliance. Indeed, to fully realize the benefit of main-charge fillings reduced vulnerability, it is essential that the booster compositions used in conjunction with these fillings have similar low vulnerability, or less sensitivity.
The decision on which EM matches an application is governed by many factors that each needs to be tradeoff to provide the most practical solution:
- Producibility (infrastructure availability, supply decisions and off-sets for ingredients)
- Technology maturity (development status, existence of specifications, whether qualified or not)
- Health &Safety (environmental considerations, toxicity)
- Sensitiveness to shock, heat and impact
For the purposes of this document, it is assumed that the other factors are satisfactory and only sensitiveness and H&S will be discussed. Since it is the energetic materials that create the hazard, it should be noted that it is necessary not only to have the energetic material Qualified in accordance with the requirements of STANAG 4170 and AOP-7, but also to take into account the characteristics of the energetic material, which determine its propensity for giving benign responses to the stimuli defined. It should be noted also, that the suitability of most of the other factors are covered by AOP-15.
Concerning the compositions used for fuze booster applications, tetryl has been for a long time the most produced and used worldwide. Nevertheless, the use of tetryl has been prohibited in Western Europe countries (France, UK, and Germany), United States and Australia at the beginning of the 80s following Health (toxicity) issues. The need to replace tetryl lead to the development of different generations of booster compositions reviewed in this document.