Development of Electrically Controlled Energetic Materials (ECEM)
| Autor: | Eugene Rozumov, Trisha Buescher, Paul E. Anderson, Paula Cook, Michael McPherson, Dana Kaminsky, Wayne N. Sawka, Kimberly Chung |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | ECS Transactions. 50:59-66 |
| ISSN: | 1938-6737 1938-5862 |
| Popis: | Recently, the Propulsion Research and Development group of the Armament Research, Development and Engineering Center has been examining a novel pyroelectric-type material developed by Digital Solid State Propulsion LLC for its unique combustion properties and insensitivity. This unique ECEM is formed using an ionic liquid oxidizer and polymer fuel, via sol-gel processes and is quite dense, making it very suitable for energetic applications in both the civilian and military fields. This ECEM is completely insensitive to the application of impact, flame, friction, and shock threats. However, once a power of the required voltage is applied, the baseline ECEM rapidly initiates combustion with H2O, CO2, and N2 formed as the only major gas phase products produced (>1%). Once the electrical power is removed the material extinguishes, but may be re-ignited again with the application of electrical power. The burning rate of ECEM can also be increased (throttled ~4x), by increasing the voltage/power applied, figure 1. However, at pressures of greater than ~200psi; once ignited, extinguishment no longer occurs when the electrical power is removed. At these elevated pressures ignition is also possible by spark/flame and electrical throttling is still observed. The response time for ignition decreases with increasing electrical power applied. At ambient pressure, ECEM ignition only occurs at voltages over 140V, but response times are slow. Once the applied voltage to an ECEM is over 200V, ignition response times are typically 60Hz). We have also determined that under atmospheric conditions, ignition of the ECEM is limited to a distance of ~1/16” (i.e. flame spreading) from the electrode. Inert metal electrodes of aluminum or stainless steel are used for igniting ECEM, with ignition occurring at the cathode. We are also able use burn-away electrical insulation to precisely control ignition location(s) and propagation direction along the cathode. We have demonstrated the broad ignition of ECEM along uninsulated electrodes of up to 8 inches in length. We have also examined metalizing these ECEMs with Boron, to both increase the flame temperature and burning rate. We have been able to achieve powered burning-rates of over six-inches a second at 1,000psi, figure 1. The addition of Boron to ECEMs causes flame sensitivity and allows self-sustaining combustion, but does not affect impact sensitivity substantially. Initial testing of ECEM in perforated pipes appears promising as indicated by uniform ignition along the entire length of the test assembly (figure 2). |
| Databáze: | OpenAIRE |
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