Enhancing reactivity of aluminum-based structural energetic materials

Reactive metals are routinely added in applications such as propellants and explosives to increase energy density and total energy output. These materials are also becoming useful in warhead casings compared to traditional inert materials because of their ability to enhance weapon output such as peak blast pressure and blast impulse. Aluminum is a good candidate for such enhanced blast applications involving structural reactive warhead casings due to its high combustion enthalpy; however, under explosive loading, conventional aluminum casings expend little of the energetic potential stored within the material. In addition, aluminum casings are capable of producing large fragments (on the order of mm's) which can be diffi cult to ignite and are accelerated away from the target, lending no additional reaction enhancement to the initial blast. This study aims to determine the most e ffective methods of increasing the reactivity of aluminum warhead casings through modi fication of alloy composition and casing geometry using controlled explosive initiation experiments. The study also explores e ffects of explosive end confi nement and impact induced fragment reactions. Transient and quasi-static pressure measurements, high speed imaging, and spatially-varying spectroscopy are performed to determine the e ffectiveness of reaction enhancement for each alloy. In addition, analysis of coarse and fine fragments collected during experiments provides insight into the role of fragmentation size and distribution on reactivity enhancement of the aluminum materials. Generation of fi ne particles below 10 microns during initial fragmentation is believed to play a key role in the casing reactivity enhancement immediately following the high explosive detonation.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Clemenson, Michael

Contributors dc:contributor

• Glumac, Nick G.
• Krier, Herman
• Stewart, Donald S.
• Lambros, John

• Casing
• Detonation
• Structural Energetic Materials
• Combustion
• Aluminum

Statement dc:rights

• Copyright 2015 Michael D. Clemenson

Handle dc:identifier

http://hdl.handle.net/2142/78705

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/78705