Manav Vohra is a PhD student at Duke University researching reactive particles. His objectives are to 1) develop and validate models for the aerobic oxidation of Zr/Al multilayers, 2) generalize these models to include biocidal particles, and 3) develop and validate models for the anaerobic reaction of Zr/Al multilayers and generalize them to include particle compacts. His research will help enable applications like high-strength materials, coatings, capacitors, and bio-agent defeat.

1. Research Overview
Manav Vohra
Duke University
March 21, 2013

2. Reactive particles
Applications:
ultra-high strength
materials
high performance
coatings
high performance
capacitors and
magnetic
transducers
smart materials for
sensors
high performance
visible optics
bio-agent defeat
(Fritz et al.)
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3. Bio-agent defeat
Background & Motivation:
Slow aerobic reactions in 1:1 Zr/Al foils
High temperatures sustained much
longer than rapid formation reactions
Temperature fluctuations during
oxidation are very small O(10−1 )
Objectives of my doctoral research:
Develop and validate aerobic oxidation
model for 1:1 Zr/Al multilayers (Joress et al.)
Generalize oxidation model for presence
of biocidal particles
Develop and validate anaerobic reaction
model for 1:1 Zr/Al multilayers
Generalize reaction model for compact
of particles
Self propagating reaction front
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4. Oxidation model
Thermal model: energy balance Comparison with experiments :
1700
Experiment
1600 Simulation
1500
Temperature(K)
1400
1300
1200
1100
1000
900
0 1 2 3 4
Time(seconds)
Kinetic models: diffusion and
interface limited growth
Foil thickness 49 µm
Foil width 12.2 mm
Number of bilayers 491
Bilayer thickness 81.5 nm
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5. Anaerobic reaction model
Estimate activation energy, Ea for foil
ignition
hot plate tests
explain low estimates
Predict diffusivity pre-exponent, Do for
low T by comparing simulations with
experiments
Uniform ignition temperature profiles
Estimate reaction velocities for different
bilayers
Estimate and optimize diffusion
parameters for high T using velocity
estimates
Propose a composite diffusivity plot
Computational domain
Manav Vohra (Duke) Research Overview March 21, 2013 5/6

6. Front propagation: Zr/Al nanolaminate foil
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