Ti/C-3Ni/Al as a Replacement Time Delay Composition
Abstract
Replacement reactive systems for the tungsten delay composition (W/BaCrO4/KClO4/diatomaceous earth) are needed due to recent concerns over the toxicity of hexavalent chromium and perchlorates. Systems based on condensed phase reactions, that are typically used in combustion synthesis (e.g. , Ti/C or Ni/Al) are of interest as replacements due to their wide range of combustion velocities and potentially low environmental impact. In this work, the combustion characteristics of the Ti/C-3Ni/Al reactive system were examined in microchannels with inner diameters ranging from 3.0-6.0 mm (i.e., similar to that of a common delay housing). It was found that this reactive system could be tailored to overcome the heat losses associated with small diameter microchannels by changing the relative amounts of Ti/C and 3Ni/Al. At 40wt.-% Ti/C content, the failure diameter was found to be between 3.0 and 4.0 mm, while at 30wt.-% Ti/C the failure diameter was between 4.8 and 6.0 mm. Measured combustion temperatures in metal microchannels were approximately 1700 K while those of unconfined pellets were around 100 K greater. Increasing Ti/C content resulted in faster combustion velocities while decreasing microchannel diameter resulted in slower combustion velocities. At these small sizes the effects of adding a thermal barrier (specifically Grafoil(TM)) to minimize radial heat losses to the microchannel were shown to be minimal with respect to combustion velocity. The Ti/C-3Ni/Al system was shown to be a suitable delay fuze composition with tunable combustion velocities ranging from 2.1-38.1 mms-1 in aluminum microchannels with diameters ranging from 4.0-6.0 mm.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 07, 2013
- Accession Number
- ADA601888
Entities
People
- Anthony P. Shaw
- Eric J. Miklaszewski
- Jay C. Poret
- Lori J. Groven
- Steven F Son
Organizations
- Purdue University