@article{conrad_jung_2007, title={Effect of an electric field applied during the solution heat treatment of the Al-Mg-Si alloy AA6022 on the subsequent natural aging kinetics}, volume={42}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-006-0850-9}, number={4}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Conrad, Hans and Jung, Kang}, year={2007}, month={Feb}, pages={1299–1303} } @article{jung_conrad_2007, title={Retardation of grain growth in electrodeposited Cu by an electric field}, volume={42}, ISSN={["0022-2461"]}, DOI={10.1007/s10853-006-0177-6}, number={11}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Jung, Kang and Conrad, Hans}, year={2007}, month={Jun}, pages={3994–4003} } @article{jung_conrad_2006, title={Effects of an electric field applied during the solution heat treatment of the Al-Mg-Si-Cu alloy AA6111 on the subsequent natural aging kinetics and tensile properties}, volume={97}, ISSN={["0044-3093"]}, DOI={10.3139/146.101216}, abstractNote={Abstract The effects of an external dc electric field of 0–5 kV/cm, applied at 475–550°C during solution heat treatment (SHT) to AA6111, on the subsequent natural aging kinetics and volume fraction of precipitated clusters were determined employing resistivity. The field increased the as-quenched resistivity and that during natural aging, the effect being significant from 0 to ≈0.5 kV/cm and increasing only slightly, if at all, thereafter. An Avrami-type analysis of the natural aging kinetics gave n = 0.59 ± 0.2 and k = (1.2 ± 0.8) · 10−2 min−1, relatively independent of SHT temperature and field strength. The field increased the volume fraction of precipitated clusters which occurred during natural aging. This was attributed to the increase in solubility during SHT produced by the field. Tensile properties equivalent to those obtained by the SHT at 550°C without a field were obtained at 500°C with a field of only 200 V/cm, representing a reduction of 50°C in the nominal SHT temperature.}, number={2}, journal={ZEITSCHRIFT FUR METALLKUNDE}, author={Jung, K and Conrad, H}, year={2006}, month={Feb}, pages={145–149} } @article{conrad_jung_2006, title={Effects of grain size from millimeters to nanometers on the flow stress of metals and compounds}, volume={35}, ISSN={["0361-5235"]}, DOI={10.1007/BF02692540}, number={5}, journal={JOURNAL OF ELECTRONIC MATERIALS}, author={Conrad, H and Jung, K}, year={2006}, month={May}, pages={857–861} } @article{jung_conrad_2006, title={Influence of electric field strength applied during the solution heat treatment of the Al-Mg-Si-Cu Alloy AA6111}, volume={97}, number={1}, journal={Zeitschrift fur MetallkundeAmerican Journal of Physiology}, author={Jung, K. and Conrad, H.}, year={2006}, pages={35–38} } @article{ramachandran_jung_narayan_conrad_2006, title={Regular and high resolution transmission electron microscopy observations on the precipitates in a naturally aged Al-Mg-Si alloy AA6022}, volume={435}, journal={Materials Science & Engineering. A, Structural Materials: Properties, Microstructure and Processing}, author={Ramachandran, S. and Jung, K. and Narayan, J. and Conrad, H.}, year={2006}, pages={693–697} } @article{conrad_ramachandran_jung_narayan_2006, title={Transmission electron microscopy observations on the microstructure of naturally aged Al-Mg-Si alloy AA6022 processed with an electric field}, volume={41}, ISSN={["1573-4803"]}, DOI={10.1007/s10853-006-0840-y}, number={22}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Conrad, H. and Ramachandran, S. and Jung, K. and Narayan, J.}, year={2006}, month={Nov}, pages={7555–7561} } @article{chia_jung_conrad_2005, title={Dislocation density model for the effect of grain size on the flow stress of a Ti-15.2 at.% Mo beta-alloy at 4.2-650 K}, volume={409}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2005.03.117}, abstractNote={Hall–Petch (H–P) plots of the effect of grain size d = 4.6–22 μm on the flow stress σ at 4.2–650 K of a β-Ti–15.2 at.% Mo alloy gave that the parameter σi increased with strain ɛ and with decrease in temperature T. In contrast, the parameter KH–P was relatively independent of ɛ and T. The corresponding dislocation density ρ increased with ɛ and with decrease in d, giving the well-known relation σ/M ≈0.5 μbρ1/2, where M is the Taylor factor. The magnitudes of σi and KH–P calculated from ρ were in reasonable agreement with those obtained from the H–P plots. The grain size dependence of σ was in accord with Li's grain boundary ledge mechanism.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Chia, KH and Jung, K and Conrad, H}, year={2005}, month={Nov}, pages={32–38} } @article{conrad_jung_2005, title={Effect of grain size from millimeters to nanometers on the flow stress and deformation kinetics of Ag}, volume={391}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2004.08.073}, abstractNote={Data on the effects of grain size, d = 9 nm to 0.26 mm on the flow stress and plastic deformation kinetics of Ag at low homologous temperatures were evaluated. Two regimes were identified for this grain-size range: Regime I (d > 500 nm) and Regime II (d ≈ 10–500 nm). The effect of grain size on the flow stress in both regimes could be described by a Hall–Petch equation. KH–P was however significantly smaller and σi larger for Regime II compared to I. Dislocation activity occurred in both regimes; dislocation cells were observed in Regime I, but not reported for II. The available data suggest that the dislocation density model governs the grain-size dependence of the flow stress in Regime I and that dislocation pile-up applies in Regime II. The rate-controlling mechanism(s) in each of the two regimes are discussed.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Conrad, H and Jung, K}, year={2005}, month={Jan}, pages={272–284} } @article{conrad_jung_2005, title={Effect of grain size from mm to nm on the flow stress and plastic deformation kinetics of Au at low homologous temperatures}, volume={406}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2005.06.051}, abstractNote={Three grain size regimes were identified: Regime I (d > ∼0.5 μm), Regime II (d ≈ 10–500 nm) and Regime III (d < ∼10 nm). Grain size hardening in accord with the Hall–Petch (H–P) equation occurred in Regimes I and II, grain size softening with the flow stress proportional to d−1 occurred in III. The rate-controlling mechanism in Regime I was concluded to be the intersection of dislocations, that in II grain boundary shear promoted by the pile-up of dislocations and that in III grain boundary shear without pile-ups. The transition from I to II occurred when the dislocation cell size became larger than the grain size, that from II to III when the dislocation elastic interaction spacing became larger than the grain size. The H–P behavior in Regime I is in accord with the dislocation density model, that in II with the dislocation pile-up model. The general behavior of Au is similar to that reported previously for Cu and Ag.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Conrad, H and Jung, K}, year={2005}, month={Oct}, pages={78–85} } @article{mcneish_jung_balik_conrad_2005, title={Effects of preparation procedure and electric field frequency on the dielectric constants and electrorheology of a zeolite/silicone oil suspension}, volume={19}, ISSN={["1793-6578"]}, DOI={10.1142/s0217979205030050}, abstractNote={ Determined were the effects of preparation procedure and electric field frequency f = dc to 105 Hz on the dielectric constants and ER response (shear rate [Formula: see text]) of a suspension in silicone oil of 23 wt.% zeolite particles originally containing 19 wt.% H 2 O . Heating the oil and the zeolite particles at 110°C both prior to, and following, mixing decreased the conductivity of the suspension more than simply heating the suspension following mixing. The double heating procedure reduced the complex dielectric constant [Formula: see text] of the particles and the complex mismatch parameter β*. The ER shear stress τ E was proportional to [Formula: see text] for the single heating and [Formula: see text] for the double heating, where [Formula: see text] is the complex dielectric constant of the silicone oil. The lower exponent corresponds to a higher water content and in turn higher conductivity of the suspension. Erratic ER response occurred for f =10 Hz in tests with [Formula: see text], but not in tests with [Formula: see text]. }, number={7-9}, journal={INTERNATIONAL JOURNAL OF MODERN PHYSICS B}, author={McNeish, D and Jung, K and Balik, CM and Conrad, H}, year={2005}, month={Apr}, pages={1191–1197} } @article{conrad_narayan_jung_2005, title={Grain size softening in nanocrystalline TiN}, volume={23}, ISSN={["0263-4368"]}, DOI={10.1016/j.ijrmhm.2005.04.016}, abstractNote={The effect of grain size d on the hardness H of TiN is considered, with focus on the nanometer grain size range. H increases from ∼22 GPa to ∼32 GPa with decrease in d from single crystals to d = 50 nm. Three sets of data show that H decreases with further reduction in d below 50 nm, i.e., grain size softening occurs. The softening is not in complete or unequivocal accord with any of the three models normally proposed for such softening, namely Coble creep, grain boundary shear and dislocation line tension modification. Factors which could have contributed to the softening are: (a) changes in texture and in turn the corresponding value of the Taylor orientation factor M and (b) the presence of weakening imperfections produced during fabrication.}, number={4-6}, journal={INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS}, author={Conrad, H and Narayan, J and Jung, K}, year={2005}, pages={301–305} } @article{conrad_jung_2005, title={On the strain rate sensitivity of the flow stress of ultrafine-grained Cu processed by equal channel angular extrusion (ECAE)}, volume={53}, ISSN={["1359-6462"]}, DOI={10.1016/j.scriptamat.2005.04.030}, abstractNote={The strain rate sensitivity of the flow stress of ultrafine-grained Cu processed by ECAE is compared with that of vapor-deposited and electrodeposited Cu. The results for all three processing methods were in accord with the model of grain boundary shear promoted by the pile-up of dislocations.}, number={5}, journal={SCRIPTA MATERIALIA}, author={Conrad, H and Jung, K}, year={2005}, month={Sep}, pages={581–584} } @article{conrad_jung_2004, title={Effects of an electric field and current on phase transformations in metals and ceramics}, volume={19}, ISSN={["1532-2475"]}, DOI={10.1081/LMMP-200028063}, abstractNote={Abstract Theoretical and experimental results on the effects of an electric field or current on solid state phase transformations in metals and ceramics are reviewed. Examples are given of the effects on both equilibria and kinetics, and the mechanisms are considered. The available results provide a foundation, but indicate the need for more work. They do, however, indicate that electric fields and currents provide additional parameters for controlling microstructure, and offer the potential for reducing processing costs and related environmental pollution.}, number={4}, journal={MATERIALS AND MANUFACTURING PROCESSES}, author={Conrad, H and Jung, K}, year={2004}, pages={573–585} } @article{conrad_jung_2004, title={Effects of an external electric field applied during the solution heat treatment of the Al-Mg-Si-Cu alloy AA6111}, volume={95}, ISSN={["0044-3093"]}, DOI={10.3139/146.017965}, abstractNote={Abstract The application of an external dc electric field during the solution heat treatment (SHT) of AA6111 Al alloy increased the as-quenched resistivity ρ and hardness Hv. The increases represented reductions in SHT of 10–20 K required for a constant ρ or Hv. Analysis of the results gave that the field reduced both the enthalpy and entropy of solution. The resulting reduction in Gibbs free energy gave increases of 0.03–0.04 at.% in solubility of Mg2Si (or Al –Mg– Si – (Cu)-vacancy complexes) at 400 –600 °C, amounting to a factor of 33% increase in solubility at 400 °C and 6% at 600 °C.}, number={5}, journal={ZEITSCHRIFT FUR METALLKUNDE}, author={Conrad, H and Jung, K}, year={2004}, month={May}, pages={352–355} } @article{jung_conrad_2004, title={External electric field applied during solution heat treatment of the Al-Mg-Si alloy AA6022}, volume={39}, ISSN={["1573-4803"]}, DOI={10.1023/B:JMSC.0000044886.66798.95}, number={21}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Jung, K and Conrad, H}, year={2004}, month={Nov}, pages={6483–6486} } @article{jung_conrad_2004, title={Microstructure gradient in 60Sn40Pb solder joints annealed under an external electric field}, volume={39}, ISSN={["0022-2461"]}, DOI={10.1023/B:JMSC.0000016189.01285.35}, number={5}, journal={JOURNAL OF MATERIALS SCIENCE}, author={Jung, K and Conrad, H}, year={2004}, month={Mar}, pages={1803–1804} } @article{jung_conrad_2003, title={Effect of an electric field on microstructure coarsening in 60Sn40Pb solder joints}, volume={356}, ISSN={["1873-4936"]}, DOI={10.1016/s0921-5093(02)00851-1}, abstractNote={The influence of an electrostatic field E=15 and 25 kV cm−1 on the microstructure coarsening in 60Sn40Pb solder joints annealed at 150 °C was determined. Without a field the following were found: (a) the eutectic Pb and Sn phase size distributions (PSDs) fit the Bitti–DiNunzio model, (b) the phase size coarsening time exponent m=0.25 and (c) the intermetallic compound (IC) growth time exponent p=0.33. The field had only a slight effect on the PSDs and on the time exponents m or p; it, however, retarded significantly the rates of phase coarsening and of IC growth. The mechanism by which the field produced the retarding effects is not clear. A likely possibility is that it reduced the governing diffusion coefficient.}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Jung, K and Conrad, H}, year={2003}, month={Sep}, pages={8–16} }