Solution Treatment (solution + treatment)

Distribution by Scientific Domains


Selected Abstracts


Influence of microstructural changes on corrosion behaviour of thermally aged Ti-6Al-7Nb alloy

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 5 2004
L. Thair
Abstract Solution treatment and ageing (STA) is an effective strengthening method for , + , titanium alloys. This paper reports the effect of solution treatment and aging on the corrosion behaviour of Ti-6Al-7Nb alloy in a simulated body fluid (Ringer's solution). Ti-6Al-7Nb alloy is hot rolled in the , + , field and subjected to solution treatment above and below its beta transus temperature (1283 K). The solution treated specimens are water quenched (WQ), air-cooled (AC), and furnace cooled (FC) at three different rates, and subsequently aged at 823 K for 4 h. Microstructural changes were examined using optical microscopy and phases developed were analyzed using XRD. The influence of microstructure on the corrosion performance of the alloys are discussed in detail based on the Open Circuit Potential (OCP), passive current density and area of repassivation loop values obtained from the cyclic polarization study in Ringer's solution. The passive current density was low (0.5 ,A/cm2) for the specimen with duplex microstructure obtained for specimen solution treated at 1223 K, air-cooled, and aged, in comparison with that for as-rolled specimen (1.5 ,A/cm2). The corrosion aspects resulting from various heat treatments are discussed in detail. [source]


Silver Surface Iodination for Enhancing the Conductivity of Conductive Composites

ADVANCED FUNCTIONAL MATERIALS, Issue 16 2010
Cheng Yang
Abstract The electrical conductivity of a silver microflake-filled conductive composites is dramatically improved after a filler surface treatment. By a simple iodine solution treatment, nonstoichiometric silver/silver iodide nanoislands form on the silver filler surface. Evidence of the decrease of surface silver oxide species is provided by TOF-SIMS and the redox property of the nanoclusters is studied using cyclic voltammetry and TOF-SIMS depth profile analyses. The redox property of the nanoclusters on silver flakes helps enhance the electrical conductivity of the conductive composites. The electrical resistivity of the improved conductive composites is measured by four-point probe method; the reliability of the printed thin film resistors is evaluated by both the 85 °C/85% relative humidity moisture exposure and the ,40 , 125 °C thermal cycling exposure. The conductive composite printed radio frequency identification (RFID) antennas with 27.5 wt% of the modified silver flake content show comparable performance in the RFID tag read range versus copper foil antennas, and better than those commercial conductive adhesives that require much higher silver content (i.e., 80 wt%). This work suggests that a surface chemistry method can significantly reduce the percolation threshold of the loading level of the silver flakes and improve the electrical conductivity of an important printed electronic passive component. [source]


Silver Surface Iodination for Enhancing the Conductivity of Conductive Composites

ADVANCED FUNCTIONAL MATERIALS, Issue 16 2010
Cheng Yang
Abstract The electrical conductivity of a silver microflake-filled conductive composites is dramatically improved after a filler surface treatment. By a simple iodine solution treatment, nonstoichiometric silver/silver iodide nanoislands form on the silver filler surface. Evidence of the decrease of surface silver oxide species is provided by TOF-SIMS and the redox property of the nanoclusters is studied using cyclic voltammetry and TOF-SIMS depth profile analyses. The redox property of the nanoclusters on silver flakes helps enhance the electrical conductivity of the conductive composites. The electrical resistivity of the improved conductive composites is measured by four-point probe method; the reliability of the printed thin film resistors is evaluated by both the 85 °C/85% relative humidity moisture exposure and the ,40 , 125 °C thermal cycling exposure. The conductive composite printed radio frequency identification (RFID) antennas with 27.5 wt% of the modified silver flake content show comparable performance in the RFID tag read range versus copper foil antennas, and better than those commercial conductive adhesives that require much higher silver content (i.e., 80 wt%). This work suggests that a surface chemistry method can significantly reduce the percolation threshold of the loading level of the silver flakes and improve the electrical conductivity of an important printed electronic passive component. [source]


Influence of high temperature and pressure ammonia solution treatment on interfacial behavior of carbon fiber/epoxy resin composites

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2009
L. H. Meng
Abstract The method of high temperature and pressure ammonia solution treatment to improve the interfacial performances of carbon fiber/epoxy composites is discussed in this study. Besides, the influence of high temperature and pressure ammonia solution treatment on carbon fiber and its reinforced epoxy composite interface performance were studied. The untreated and treated carbon fibers were characterized by monofilament tensile test, X-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). The interfacial adhesion of the untreated and treated carbon fibers reinforced epoxy resin composites were also evaluated by interface shear strength (IFSS) test, interlaminar shear strength (ILSS) test, and fracture morphology analysis. It was found that the interfacial adhesion of composites increased greatly after high temperature and pressure ammonia solution treatment. The improvement of interfacial adhesion was attributed to the increase of polar functional groups and surface roughness of carbon fibers surface after treatment. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source]


Influence of microstructural changes on corrosion behaviour of thermally aged Ti-6Al-7Nb alloy

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 5 2004
L. Thair
Abstract Solution treatment and ageing (STA) is an effective strengthening method for , + , titanium alloys. This paper reports the effect of solution treatment and aging on the corrosion behaviour of Ti-6Al-7Nb alloy in a simulated body fluid (Ringer's solution). Ti-6Al-7Nb alloy is hot rolled in the , + , field and subjected to solution treatment above and below its beta transus temperature (1283 K). The solution treated specimens are water quenched (WQ), air-cooled (AC), and furnace cooled (FC) at three different rates, and subsequently aged at 823 K for 4 h. Microstructural changes were examined using optical microscopy and phases developed were analyzed using XRD. The influence of microstructure on the corrosion performance of the alloys are discussed in detail based on the Open Circuit Potential (OCP), passive current density and area of repassivation loop values obtained from the cyclic polarization study in Ringer's solution. The passive current density was low (0.5 ,A/cm2) for the specimen with duplex microstructure obtained for specimen solution treated at 1223 K, air-cooled, and aged, in comparison with that for as-rolled specimen (1.5 ,A/cm2). The corrosion aspects resulting from various heat treatments are discussed in detail. [source]


Specific Determination of Endothelial Cell Viability in the Whole Cell Fraction from Cryopreserved Canine Femoral Veins Using Flow Cytometry

ARTIFICIAL ORGANS, Issue 10 2000
Jong-Chul Park
Abstract: An efficient method for specifically determining the viability of endothelial cells (EC) from cells dissociated from the human saphenous vein was investigated. Three different methods, trypan blue staining assay, [3H]-proline incorporation assay, and flow cytometry (FCM), combined with the fluorescein isothiocyanate conjugated with Griffonia simplicifolia agglutins (GS1-FITC)/propidium iodide (PI) double staining, were used. Both trypan blue staining and [3H] proline incorporation assays demonstrated less sensitivity to determine viability of EC differentially from the other cells. FITC-GS1 showed prominent binding to the vascular EC and could be counted by FCM including PI on dead cells. Following the cryopreservation process, the GS1-FITC/PI FCM analytical method was adopted to test simultaneously the viability of whole cells and EC from the same tissue, human saphenous veins, and mongrel dogs' femoral veins after harvesting, antibiotic solution treatment, and thawing. The viability of the whole cells from veins decreased with a significant difference (p < 0.05) from that of EC after thawing. [source]


Comparative effects of deltamethrin and Neem kernel solution treatments on Diamondback moth and Cotesia plutellae (Hym., Braconidae) parasitoid populations in the Cotonou peri-urban area in Benin

JOURNAL OF APPLIED ENTOMOLOGY, Issue 3-4 2000
A. E. Goudegnon
A comparison between deltamethrin and Neem kernel solution treatments on Plutella xylostella (L.) populations was made in the Cotonou peri-urban area. Diamondback moth populations were 10 times larger in deltamethrin plots, than in Neem plots after treatment. The number of marketable cabbages from Neem-treated plots was 1.5 times greater than the number from deltamethrin-treated plots. There was no apparent effect of either treatments on Cotesia plutellae (Kurdjumov) populations, the only parasitoid of the pest that was present in the area. [source]


EFFECTS OF DIFFERENT SAMPLE PREPARATION METHODS ON STABLE CARBON AND OXYGEN ISOTOPE VALUES OF BONE APATITE: A COMPARISON OF TWO TREATMENT PROTOCOLS*

ARCHAEOMETRY, Issue 1 2010
C. J. YODER
Researchers have long debated the appropriateness of stable isotope analysis of bone apatite to reconstruct the diets of ancient animals. The debate has centred, in part, on diagenesis of bone mineral from interaction with the burial environment. A number of acetic acid treatments are used to remove diagenetic carbonates from samples; however, less is known on how different protocols alter stable isotope values. We compare two common acetic acid solution treatments (0.1 M versus 1.0 M-buffered) to examine the effects on carbon and oxygen isotope values and Fourier transform infrared spectroscopy (FTIR) spectra in human bone from different burial contexts. Results indicate that both treatments have a similar effect on isotope values and FTIR spectra in bone apatite. [source]