2018 Aerospace Materials for Extreme Environment Program Review Controlling High-T Ceramic Grain Boundaries with E Fields Understanding the Mechanisms of Flash Sintering and Beyond
Jian Luo University of California, San Diego May 16, 2018 The Phillips Technology Institute Collaboration Center
Acknowledgement: Students: Jiuyuan Nie (Ph.D. student), Yuanyao Zhang (Ph.D., Sept 2016; currently employed at Lam Research) and Tao Hu (partial postdoc; TEM) AFOSR Program Manager: Dr. Ali Sayir AFOSR Grant no. FA9550-14-1-0174 September 2014 – August 2019 Jian Luo Background: Prior Studies & Motivation Selected AFOSR Project Achievement (I) Innovative Sintering 3YSZ Cold Sintering Clive Randall et al. (e.g., ACS AMI 2016)
Flash Sintering 3YSZ Rishi Raj et al. higher JACerS 2010 Specimen T <200 C, H2O-assisted (hydrothermal), ~1 h Typically Needed: Post Annealing at Reduced T
From This AFOSR Project: Water-Assisted Flash Sintering (WAFS)
ZnO Nie, Zhang, Chan, Huang, Luo Scripta Materialia 142: 79-82 (2018) Jian Luo Background: Prior Studies & Motivation Selected AFOSR Project Discoveries (II) Electric Fields on Microstructural Development? Inhibit Grain Promote Grain Growth? Growth?
3YSZ
Raj et al. Conrad (JACerS 2011) (JACerS 2009)
Bi2O3-doped ZnO To induce space charges at GBs?
Our Most Recent AFOSR Work Jian Luo The Scientific Questions and Technological Opportunities of Our Example of ZnO Flash Sintering Flash Sintering Acta Mater. 2017 + Viewpoint: Scripta Mater. 2018
More More Open ScientificQ’s 2% (1) How does flash start? 0% -2% Einitial = 300 V/cm -4% Conventional (2) How does rapid densification occur? -6% Sintering -8% (E = 0) -10% 5 C/m (3) Can we control microstructures? 20 mA/mm2 ~89% E.g., nano ceramics? Bimodal microstructures? -12% -14% Linear Shrinkage Linear 30 mA/mm2 ~94% -16% (4) Can we start a flash at room temperature? J = 39 mA/mm2 -18% max ~97% density in 30 s Water-Assisted Flash Sintering (WAFS) -20% 0 200 400 600 800 1000 1200 Furnace Temperature (T , oC) (5) Can electric field/current/potential affect F microstructural development? Jian Luo (1) How does a flash start? Differential Heat 2 d VS Generation Rate E Per Unit Surface Area dTSS A
3 4Stefan TS Differential Heat Dissipation Rate Per Unit Surface Area
An unstable temperature rise or a Coupled Thermal & Electric Runaway will occur if: Specimen & Surface Area 23dQ EVTASSS4Stefan dTSS T If heat radiation dominates… Differential Differential Heat Heat Generation Dissipation Rate Rate
Zhang et al., Acta Materialia 2015 & 2017 Viewpoint: Luo, Scripta Materialia 2018 Jian Luo (1) How does the flash start? Testing Our Model: “Onset Flash = Coupled Thermal and Electric Runaway”
Three Notes (Open Q’s): We showed that a flash can start as a thermal runaway (for ~ 20 cases), but: 1) it does not exclude the possibility that a discontinuous increase in (T) (due to a 1st-order transition or defect avalanche) can trigger a thermal runaway a flash; 2) it explains how flash starts, but not the fast densification (that is indeed faster than expected) mechanisms; and 3) it does not exclude possible
• AtmosphereAl“Flash”TiOelectric2O2:3 adoping systematic of single field/current/potential dependenceincreases8YSZ crystals validation(vs. the ZnO ((new newconductivity of): discoveryourdiscovery model of)) •ZnOnewwithSurfaceseffects, tosurfacemethoddifferent promote are which 2 to -more Dphases control electronflash. insulatingindeed (anatase gas exist(~10( vs.vs.12 conductiverutile)e/cm and2 ):&can ) •smallerReducingdopingArbeor significant H (undoped,particles2 reducesatmosphere ( cation,vs.more increases moreconductiveanionic) )conductive conductivity Jian Luo (2) How does rapid densification occur? 2% Flash 0% The First 30 Seconds! -2% Einitial = 300 V/cm -4% Conventional -6% E = Sintering initial 2 -8% (E = 0) 100 300 V/cm Jmax ≈ 30 mA/mm 0.015 Specimen 0.8 -10% 2 90 Jmax = 20 mA/mm 5 C/m 0.7 Conductivity Imax = 0.5 A ~89% 80 -12% 0.6 0.010 2 70 -14% Jmax = 30 mA/mm 0.5 Shrinkage Linear 60 Imax = 0.75 A ~94% 0.4 -16% 50 2 0.3 0.005 -18% Jmax = 39 mA/mm
Voltage (V) Voltage ~97% density in 30 s 40 (A) Current Imax = 1 A 0.2 -20% 30
Conductivity (S/cm) Conductivity σ 0.1 I V 0.000 0 200 400 600 800 1000 1200 20 0.0 Furnace Temperature (T , oC) -10 0 10 20 30 -10 0 10 20 30 -10 0 10 20 30 F Time (sec) Time (sec) Time (sec)
Power Jmax TS Final Density! 1 ~120 nm ~260 nm Density 2%
) 3 ~61% density 0% ~400 nm
W/mm
( 0.1 -2%
-4%
Power Density Density Power -6% 0.01 -10 0 10 20 30 -8% Time (sec) -10% 5 s
)
C o 1600 -12%
,
s
Linear Shrinkage Linear
T ( Estimated 1400 -14% Densification levels off after ~20-30s TS ~1200 C 1200 -16% 20 s 30 s
1000 ~200 C/s -10 0 10 20 30 ~1 μm 800 Time (sec)
600
EstimatedSpecimen Temperature -10 0 10 20 30 Time (sec) Jian Luo (2) How does rapid densification occur? Rapid Thermal Annealing (RTA) to Mimic the T(t) Profile in Flash Sintering Comparable T(t) Profiles Densification Similar Densification & Grain Growth Rates Flash Sintering
TSteady-State (Imax = 0.75 A) = ~ 1040°C – 1160°C TSteady-State (Imax = 0.5 A) = ~ 920°C – 1050°C Rapid Thermal Annealing (RTA)
Grain Growth Intense IR Heating Heating @ 200°C/s; Isothermal for 0-30 s Jian Luo (2) How does rapid densification occur? Controlled (Step-wise) Heating Rate Experiments Importance of Ultrahigh dT/dt 1.0 1 step 0.9 Conventional 0% 0.8 0.7 0.6 -5% 0.5 0.4 -10% 0.3
Shrinkage Current (A) Current 7 steps 0.2 86.7% density 0.1 0.1 A/100 s -15% 0.0 94% density (in 20 s) -100 0 100 200 300 400 500 600 700 800 -100 0 100 200 300 400 500 600 700 800 Time (sec) Time (sec)
2 Identical Emax = 300 V/cm and the final Imax = 0.75 A (Jmax = 30 mA/mm ) Reducing effective ramp rate: by increasing Imax in 7 steps, or 0.1A/100s
The Benefits of Ultrahigh dT/dt (Detailed Discussion in the Next 2 Slides…): 1) helping a competition between densification (via GB diffusion at high T) vs. particle coarsening (via surface diffusion at low T) to keep sintering driving force 2) leading to non-equilibrium defects, e.g., non-equilibrium grain boundaries, with higher diffusivities ? Zhang et al. Acta Mater. 2017; Luo, Scripta Mater. 2018 Jian Luo (2) How does rapid densification occur? How Does Ultrahigh dT/dt Help? Ultrahigh dT/dt (~ 200 C/s for ZnO): Helpping a competition between densification (via GB diffusion @ high T) vs. coarsening (via surface diffusion @ low T) to keep high sintering driving force E.g., 10% less coarsening 2X the sintering rate ( G4) Zhang et al. Acta Mater. 2017; Luo, Scripta Mater. 2018
Demonstrated also for 3YSZ by Professor Todd & co-workers (Oxford) Ultra-fast heating can accelerate the sintering of 3YSZ by >100X without E Jian Luo (2) How does rapid densification occur? Todd et al.: Ultrahigh dT/dt Non-Equilibrium Grain Boundaries w/ Increased Diffusion
How to probe non-equilibrium grain boundaries? • In situ (seems difficult)? • Doping & quenching? • Modeling? ? Grain Boundary Structural Transitions? Jian Luo (3) Can we control microstructures? Fast Densification of Nanocrystalline Ceramics w/ Suppressed Grain Growth? Two-Step Flash Sintering (TSFS)
❷
There❷ 3 A is also30 s a97.6% competition between: ❹ • grain growth (via diffusion // GB at relatively❶ ❸ high T) vs. • densification (via diffusion ⊥ GB at relatively low T), which5 µm is in part responsible for two-step sintering. 1.75 ± 0.16 µm ❶ 3 A 6 s 90.3% ❸ 3 A 6 s + 2 A 150 s ❹ 3 A 6 s + 2 A 300 s Nie et al. Recall Ultrahigh dT/dt: To help a competition between 96.5% Scripta Mater. 94.7% 141: 6 (2017) • densification (via GB diffusion at high T) vs. • particle coarsening (via surface diffusion at low T) 2 µm 2 µm 2 µm to keep sintering267 ± 30 nm driving force.330 ± 28 nm 370 ± 17 nm Jian Luo (3) Can we control microstructures? Two-Step Flash Sintering (TSFS): >200X Faster Than Conventional Two-Step Sintering
Better Results, Nie et al. Scripta Materialia 141: 6-9 (2017) >200X Faster
Conventional Two-Step Sintering of ZnO to Achieve Similar Results in ~72,000 s
Mazaheri, Zahedi, & Sadmezhaad J. Am. Ceram. Soc. 91: 56 (2008) Jian Luo (3) Can we control microstructures (& defects)? Beyond Two-Step Flash Sintering (TSFS)?
The flash sintering scheme allow Flash Sintering Bimodal Microstructures a direct control of I(t) and T(t) profiles to much better precisions and higher speeds! Open Questions (Future Studies or Opportunities): 1) Can we control I(t) and T(t) to achieve more exotic microstructures, e.g., bimodal misconstrues? 2) Can we pattern the electrodes to achieve graded microstructures? 3) Can we use flash sintering to make highly-defective materials? Jian Luo (4) Can we start a flash at room temperature? Water-Assisted Flash Sintering (WAFS)
Optimization Guided by the Model in Ar – 5% H2 Our Example of ZnO (Tmelting = 1975 C) Flash at T = 108 C! 2% Flash F 0% ~97% Density in <30 s -2% Einitial = 300 V/cm (Grain Size: ~1 m) -4% Conventional -6% Sintering (E = 0) -8% 5 C/m -10% -12% -14%
Linear Shrinkage Linear -16% J = ~97% density in 30 s -18% max 2 39 mA/mm (Tfurnace < 650 C) -20% 0 200 400 600 800 1000 1200 Furnace Temperature (T , oC) F Zhang & Luo, Scripta Mater. 2015
Cold Sintering Our Recent Attempt (following Randall et al.): JPS 2018 Clive Randall et al. (e.g., ACS AMI 2016)
<200 C, H2O-assisted (hydrothermal), ~1 h Typically Needed: PostNie, Annealing Zhang, atChan, Reduced Huang T & Luo, Scripta Mater. 142: 79-82 (2018) Jian Luo (4) Can we start a flash at room temperature? Water-Assisted Flash Sintering of ZnO: Bifurcation in Kinetic Pathways Nie, Zhang, Chan, Huang & Luo, Scripta Mater. 142:79-82 (2018) 2 TF = 23°C; Nominal Jmax ≈ 75 A/mm ; Ar + 5% H2 + H2O Vapor Einitial = 200 V/cm 98.3 ± 0.7%
1
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200 3 200 V/cm Sintered 150 5 µm
150 V/cm W/mm 1.83 ± 0.30 µm
( 100 V/cm Not 100 Sintered 1400 1300 (e) 50 0.1 1200
)
C 1100
o
(
s
0 T 1000
0 10 20 30 Density Power 0 10 20 30 900
Nominal Electric Field (V/cm) Field Electric Nominal 4.0 Time (s) 0.4 Time (s) 800 3.5 Nominal J 700
max Estimated Not 600 3.0 ≈ 75 mA/mm2 0.3 Sintered 500 2.5 0 10 20 30 0.2 Time (s) 2.0 Identical Jmax 1.5 after <5 s 0.1 Sintered 1.0 ~55%
Current (A)
0.5 0.0 0.0
0 10 20 30 (S/cm) Specimen Conductivity 0 10 20 30 Time (s) Time (s) 500 nm
Einitial = 100 V/cm Jian Luo (4) Can we start a flash at room temperature? Water-Assisted Flash Sintering: Possible Mechanisms?
The Effects of H2O? It is • Increase conductivity to “interfacial H2O,” enable RT flash i.e. H2O or OH Conductivities are adsorbed on ZnO • Also promote mass >10 times higher surfaces/interfaces transport ??? with smaller particle Guillon et al.: H O-assited SPS of 10 2 ZnO (~36 nm ± 2 nm) ZnO [J. European Ceram. Soc. 36 1 (2016) 1207-32] 57.3 ± 0.8% density 0.1 Cold sintering of ZnO also 0.01 ZnO ( 120 ± 50 nm) demonstrated [Clive et al.] 54.8 ± 0.4% density 1E-3 1E-4 Specimen Conductivity During 1E-5 Furnace Heating DI water 1E-6 T ( C) saturated w/ ZnO F 500400 300 200 100 1E-7 1 1E-8 DI water
Specimen (S/cm) Conductivity 0 10 20 30 40 50 60 0.1 20 C/min Time (min) 0.01 The conductivity of the DI water 1E-3 Wet Ar + H 2 Ultrahigh 200 C/S? (statured with 1E-4 Dry Ar + H2 ZnO) is much lower 1E-5 Open Questions 1E-6 1.5 2.0 2.5 3.0 3.5 (Future Studies)
Specimen Conductivity (S/cm) Specimen Conductivity 1000/T (1/K) F Jian Luo (4) Can we start a flash at room temperature? Methanol-Assisted Flash Sintering: Starting @ Room T 1 The kinetic pathway is complex & intriguing! 0.1 DI Water (Relative Polarity = 1) 0.01 ~93%-96% density 1E-3 Methanol 1E-4 (0.762) 1E-5 Isopropyl 1E-6 Alcohol Ar + 5% H + vapor (0.542) 2 1E-7 ZnO (120 nm) 1E-8
Specimen (S/cm) Conductivity 0 10 20 30 40 50 60
) Time (min) 400 0.5 Not 350
V/cm Sintered 0.89 ± 0.06 µm ( 0.4 300 400 V/cm
250 300 V/cm 0.3 200 2 0.2 T = 23°C; J ≈ 93 A/mm 150 F max 100 0.1 Sintered Ar +5% H2 + Methanol Vapor 50 0.0 0 0 10 20 30 0 10 20 30
Nominal Electric Field Field Electric Nominal Turn off by itself 4.0 Time (s) 1500 Specimen Conductivity (S/cm) Specimen Conductivity Time (s)
2 ) 3.5 Jmax ≈ 93 mA/mm 3 1400 Furture Study Needed 1 3.0 Sintered 1300 ) Sintered
C
o 1200
2.5 (
W/mm
( S 1100 2.0 T 1000 Methanol-Assisted 1.5 Not 900 1.0 Flash Sintering Current (A) 800 0.1 Sintered Not 0.5 Estimated 700 Start at Room T (23°C) Sintered 2 0.0 600 Jmax ≈ 93 A/mm
0 10 20 30 Density Power 0 10 20 30 0 10 20 30 Ar + 5% H + Methanol Vapor Time (s) Time (s) Time (s) 2 Jian Luo (5) Can electric field/current/potential affect microstructural development? Enhanced Grain Growth at the Cathode vs. Anode Side
2 3YSZ 250 mA/mm , Ts = 1450 °C for 20 h
Oxygen Oxygen Accumulation ion
Y2O3 Oxygen Deficiency Deficiency Oxygen
Y Dong, H Wang, & IW Chen, J. Am. Ceram. Soc., 100(3), 876-886, (2017). YSZ: cathode-side reduction “n type – i – p type” 2 ZnO, Jmax ~39 A/mm In ZnO, enhanced grain growth at the anode side. Our Hypothesis: Electric Potential-Induced Grain Boundary (GB) Oxidation Transition 1 ´ ¢ e¢+ 2 O2 (gas) ® OO + VZn ¢ ¢¢ e¢+ VZn® VZn Anode Side Enhanced Grain Growth Electrochemically-driven extreme redox conditions 5 μm (very high/low PO2 locally) and gradients (e.g., as illustrated by Bilge Yildiz’s talk yesterday) Jian Luo (5) Can electric field/current/potential affect microstructural development? Electric Potential-Induced GB Oxidation Transition E = 300 V/cm, Future Studies: To prove the 2 in air Jmax = 15.4 A/cm hypothesis more directly? 1) Controlled grain growth (GG) at 3.5 ± 1.8 μm 32.3 ± 5.6 μm different atmospheres 2) GG in single/polycrystal specimens (more later)
3) Directly probing defects? E = 500 V/cm in Ar + 5% H 2 2 Jmax = 15.4 A/cm 0.9 ± 0.3 μm 1.0 ± 0.3 μm
5 m 5 m Example in litaerature: Acta Materialia 119 (2016) 136e144 Anode-side enhanced grain growth largely disappeared in a reducing atmosphere that suppresses interfacial oxidation, attesting our hypothesis Jian Luo (5) Can electric field/current/potential affect microstructural development? New Controlled Experiments: Bi2O3-doped ZnO Sandwich Specimens
To Introduce Space Charges at (Liquid-like) Grain Boundaries SingleCrystal (SC)
• TFurnace = 840 °C 4 h
Polycrystal Polycrystal (PC) Polycrystal (PC) PC • TSpecimen < 875 °C (w/ Joule heating) • Fixed Small J = 6.4 mA/mm2 • Steady state reached in ~30 m:
• ~0.6 V/cm in SC & 1.6 V/cm in PC PC
Reference:
• TF = 880 °C, 4 h • No electric field/current 5.0 x 5.0 x ~1.6 mm3
3.63 ± 0.91 µm Reference: (E = 0) 3.60 ± 0.79 µm
)
)
ퟎ
ퟎ
ഥ
ퟐ
ഥ
ퟐ ퟏ
PC ퟏ SC 80 µm PC
ퟏ
ퟏ
(
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0.79 µm µm 0.79
0.91 µm 0.91 ± ± PC PC 20 µm 20 µm
ഥ ഥ 3.60 3.60 3.63 (ퟏퟏퟐퟎ) SC (ퟏퟏퟐퟎ) TK GuptaSC, J. Am. Ceram. Soc. TF = 880 °C for 4 hours without an electric field/current Similar grain growth on both sides of the single crystal.73, 1817-1840 (1990) Jian Luo (5) Can electric field/current/potential affect microstructural development? ഥ Bi2O3-doped ZnO Sandwich Grain Growth Experiments: (ퟏퟏퟐퟎ)
2
TF = 840 °C for 4 hours under a constant current density J = 6.4 mA/mm
(
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ퟎ
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ഥ ഥ
ퟐ E ퟎ
PC ퟏ PC 100 µm
) ퟏ
( SC
PC E 50 µm SC (ퟏퟏퟐഥퟎ) PC E
20 µm 0.82 µm µm 0.82 3.04 µm 3.04 (ퟏퟏퟐഥퟎ) SC
EBSD Euler Map ±
14 SC // -E 12 SC // +E PC m)
10 SC w/o E
8
E 6
SC (ퟏퟏퟐഥퟎ) 4
2 Enhanced Grain Growth Average Grain Growth ( along -E Direction 0.0 0.2 0.4 0.6 0.8 1.0 Normalized Location Jian Luo Aberration-Corrected STEM of Atomic-Level Grain Boundary (GB) Structures Fast-Moving GB Anti-Parallel to the E Field: Highly Ordered
HAADF BF SC SC PC PC
E
[ퟎퟎퟎퟏ]
Reference: E = 0 Amorphous-Like Jian Luo Aberration-Corrected STEM of Atomic-Level Grain Boundary (GB) Structures Slow-Moving GB Parallel to the E Field: More Disrdered
PC SC PC SC
E
[ퟎퟎퟎퟏ]
HAADF BF Jian Luo (5) Can electric field/current/potential affect microstructural development? ഥ Bi2O3-doped ZnO Sandwich Grain Growth Experiments: (ퟏퟏퟐퟎ)
Slow-Moving GB // +E Fast-Moving GB // -E
(
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ഥ
ퟐ ퟐ
E ഥ ퟏ
PC ퟎ PC 100 µm
ퟏ )
( SC Surprising Results: 1) Can E order GB? 2) Why do ordered GB move faster (the opposite expected)?
More Disordered Highly Ordered Jian Luo (5) Can electric field/current/potential affect microstructural development? ഥ Bi2O3-doped ZnO Sandwich Grain Growth Experiments: (ퟏퟏퟐퟎ)
Abnormal Grain Growth near the (-) electrode
Inverse pole figure coloring X of Y or E direction Y
For Comparison: Flash E Sintered Pure ZnO
<ퟏퟏퟐഥퟎ>
<ퟏퟏퟐഥퟎ>
<ퟏퟏퟐഥퟎ> Jian Luo (5) Can electric field/current/potential affect microstructural development?
Bi2O3-doped ZnO Grain Growth Experiments: Polycrystals Electrically-Driving Pore Migration? Electro Sintering? E 2.2 TF = 840 °C for 4 hours, 2.0 J = 6.4 mA/mm2
m) 1.8
1.6
1.4 TF = 865 °C for 4 hours,
Grain Size ( Size Grain 1.2 without Electric Field/Current 1.0 0.0 0.2 0.4 0.6 0.8 1.0 Normalized Distance from Cathode 5 40 µm 4 Increased TF = 840 °C for 4 3 porosity hours, J = 6.4 4 µm mA/mm2 near anode 2
Porosity (%) Porosity 1
0 0.0 0.2 0.4 0.6 0.8 1.0 Normalized Distance from Cathode E Jian Luo (5) Can electric field/current/potential affect microstructural development?
Bi2O3-doped ZnO Sandwich Grain Growth Experiments: (0001)
No detectable grain growth at either Abnormal side of (ퟎퟎퟎퟏ) SC, which differs from Grain Growth that case of (ퟏퟏퟐഥퟎ)
E (0001)
PC SC PC (0001) 100 µm
PC SC SCSC PC SC PC SC PC De-densification?
20 µm 20 µm Jian Luo New Scientific Questions and Technological Opportunities: Interfacial-Liquid-Activated and Electrically-Driven Ultrafast Sintering and Far-From-Equilibrium Microstructural Evolution Case I: Water/Solvent Assisted Flash Sintering Exciting Opportunities, but Open Q’s: • The kinetic pathway is intriguing. • Extendable to other systems? ZnO Likely, but only narrow processing windows (trials & errors difficult) • Mechanism-based predictive model(s) needed!
Both are Far-from Equilibrium: • interfacial liquids Ultrahigh dT/dt (Case I) • Electrochemically-driven extreme Case II: High-T Interfacial Liquid-Like Phase redox conditions and gradients
Both scientifically Interesting and Technologically Relevant, but Highly Controversial: How applied electric fields, currents, and/or potentials affect the microstructural evolution in real materials with impurities at high T’s T GB Disordering Space Charges E Jian Luo Conclusions/Accomplishments Key Open Questions (1) How does flash start? 1) A jump in (T) due to a 1st-order transition or defect avalanche
More More Open Scientific Coupled thermal & electric runaway Predictive model: more cases validated… thermal runaway a flash? 2) Non-equilibrium grain (2) How does rapid densification occur? boundaries or other defects Ultrahigh dT/dt critical also enhance diffusion? Competition b/ coarsening & sintering 3) Can we used a designed I(t) (3) Can we control microstructures? beyond 2-step and/or patterned electrodes to control Qestions Yes, e.g., 2-step flash sintering to suppress microstructure further?? grain growth: >100X faster than conventional 4)Can we develop mechanism- (4) Can we start a flash at room temperature? based predictive models for & Opportunities… & Yes: water (solvent)-assisted slash sintering water (solvent)-assisted slash sintering??? (5) Can electric field/current/potential affect microstructural development? 5) How?? Why??? Yes! Scripta Materialia 146: 260-6 (2018) Jian Luo Discussion Leader/Invited Speaker Session 1: Yiquan Wu (Alfred) Tobias A. Schaedler (HRL) Rebecca Dylla-Spears (LLNL) Session 2: Ming Tang (Rice) I-Wei Chen (U. Penn.) Wayne Kaplan (Technion, Israel) R. Edwin García (Purdue) Session 3: Antti Makinen (ONR) Richard Todd (Oxford, UK) Haiyan Wang (Purdue) Session 4: James Warren (NIST) Krishna Rajan (U. Buffalo) Wenqing Zhang (SUSTech, China) Elizabeth A. Holm (CMU) Session 5: Alexis Lewis (NSF) Jon-Paul Maria (NCSU/PSU) B. Reeja Jayan (CMU) Session 6: Monika Backhaus (Corning) Sossina Haile (Northwestern U) Miaofang Chi (ONRL) Sung-Yoon Chung (KAIST, Korea) Session 7: Eric Wuchina (ONR) Yury Gogotsi (Drexel) Don Brenner (NCSU) Elizabeth Opila (Virginia) Session 8: Vann Heng (Boeing) Nitin Padture (Brown) Bill Fahrenholtz (Missouri S&T) Randall Hay (AFRL) Session 9: Greg Rohrer (CMU) Maria A. Loi (U. Groningen, Netherlands) 2-3 short talks selected from posters