Water Versus Acetone Electrophoretic Deposition of Hydroxyapatite on 316L Stainless Steel

2006 ◽  
Vol 314 ◽  
pp. 237-244 ◽  
Author(s):  
Georgina García-Ruiz ◽  
Gregorio Vargas ◽  
J. Méndez-Nonell ◽  
A. Uribe S.
Keyword(s):  
Stainless Steel ◽  
Deposition Time ◽  
316L Stainless Steel ◽  
Average Particle Size ◽  
High Resistivity ◽  
Average Particle ◽  
Water Suspensions ◽  
Before And After ◽  
The Difference ◽  
Deposit Weight

Hydroxyapatite (HAP) was electrophoretically deposited on 316L stainless steel in order to promote a bioactive surface. The effect of dispersing media (water and acetone), applied voltage and the deposition time on the deposit weight and microstructure of the coatings was evaluated. The deposition time was varied in the range of 1 to 900 s for water suspensions and 0.5 to 180 s for acetone suspensions. Suspensions were prepared by using HAP powder with an average particle size of 1.5 μm at a concentration of 1 % by weight. The deposition was performed under a direct current (DC) field of 400 to 1000 V for acetone suspensions and 5 to 50 V for water suspensions. The coatings were analyzed using scanning electron microscopy. The amount of hydroxyapatite on the surface of the metallic substrate was evaluated by determining the difference in weight of the samples, before and after the electrophoretic process. The stabilization of HAP particles in water was achieved using 1 % by weight of Dispex N40TM and 0.001M KCl. Under this condition the zeta potential of HAP in water suspension was –28 mV. Non additive was required in acetone suspensions. Dense, homogeneous and crack-free coatings of sub-micron particles (0.63 mg/cm2) were obtained by applying 5 V during 60 s in water suspensions. Above a DC field of 5 V the hydrolysis of water seriously difficulties the coatings formation. Homogeneous and crack-free coatings of sub-micron particles (1.45 mg/cm2) were also obtained in acetone suspensions applying 400 to 1000 V during 5 s. Lower voltages were not used with acetone suspensions due to its high resistivity.

scholarly journals Difference in the bed load transport of graded and uniform sediments during floods: An experimental investigation

2019 ◽  
Vol 50 (6) ◽  
pp. 1645-1664
Author(s):  
Khabat Khosravi ◽  
Amir H. N. Chegini ◽  
Andrew D. Binns ◽  
Prasad Daggupati ◽  
Luca Mao
Keyword(s):  
Hysteresis Loop ◽  
Average Particle Size ◽  
Equal Weight ◽  
Average Particle ◽  
Uniform Particles ◽  
Before And After ◽  
Load Transport ◽  
The Difference ◽  
Sediment Mixture ◽  
Bed Material

Abstract The objective of this study was to experimentally evaluate the difference in the transport of uniform (5.17, 10.35, 14, 20.7 mm) and graded sediment (mixture of these rounded particles with equal weight proportions) under different unsteady flow hydrographs in a 12 m long, 0.5 m wide and deep glass-walled flume. There was a lag time between fractions and uniform particles, such that peaks of coarser and finer fraction particles occurred before and after the peak of uniform sediment with the same size, respectively. Comparison between uniform particles and fractions in graded sediment showed that the sediment transport rate of fine and coarse fractions was lower and higher than their counterpart uniform particles, respectively. Overall, the uniform particles demonstrated a clockwise hysteresis loop and graded sediment had a counterclockwise hysteresis loop. The mobility of coarser fractions increased during the rising limb of hydrograph, whereas the mobility of finer fractions increased during the falling limb. In general, the mobility of coarse fractions increased and that of fine fractions reduced. Result of transported sediment showed that average particle size collected in traps (Db50) was coarser than bed material (Ds50) on both limbs. The relative transport ratio for uniform and graded sediment is higher and lower than 1, respectively.

Electrophoretic Deposition of Wollastonite on 316L Stainless Steel from Different Dispersing Media

2006 ◽  
Vol 314 ◽  
pp. 231-236 ◽  
Author(s):  
Hugo H. Rodríguez ◽  
Gregorio Vargas ◽  
Dora A. Cortés-Hernández
Keyword(s):  
Particle Size ◽  
Stainless Steel ◽  
Electrophoretic Deposition ◽  
Deposition Time ◽  
316L Stainless Steel ◽  
Processing Conditions ◽  
Metallic Substrates ◽  
Propyl Alcohol ◽  
Mean Particle Size ◽  
Deposit Weight

Natural wollastonite was electrophoretically deposited on 316L stainless steel in order to promote a bioactive surface. The effect of the disperse media and the deposition time on the deposit weight and microstructure of the wollastonite coatings was evaluated. The disperse media were methanol, acetone, ethanol, propyl alcohol and the deposition time was in the range of 1 to 180 s. Suspensions were prepared by using wollastonite powder with a mean particle size of 2 μm at a concentration of 1 g/L. The deposition was performed under a DC field of 800 V. The coated substrates were sintered at temperatures ranging from 900 to 1050oC in air for 2 to 4 h. Dense, homogeneous and crack-free coatings were obtained by using methanol and acetone. No wollastonite coating was obtained by using ethanol at these processing conditions and few wollastonite particles were deposited on the metallic substrates by using propyl alcohol. The deposit weight increases as the deposition time is increased in all the cases.

scholarly journals Improving the Corrosion Resistance of AISI 316L Steel for Semiconductor Piping by Controlled Delta-Ferrite Content

2022 ◽  
Vol 60 (1) ◽  
pp. 46-52
Author(s):  
Young Woo Seo ◽  
Chan Yang Kim ◽  
Bo Kyung Seo ◽  
Won Sub Chung
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
316L Stainless Steel ◽  
Sem Analysis ◽  
Ferrite Content ◽  
Aisi 316L ◽  
Delta Ferrite ◽  
Aisi 316L Stainless Steel ◽  
316L Steel ◽  
The Difference

This study evaluated changes in delta-ferrite content depending on the preheating of AISI 316L stainless steel. We also determined the reasons for the variation in delta-ferrite content, which affects corrosion resistance. Changes in delta-ferrite content after preheating was confirmed using a Feritscope, and the microstructure was analyzed using optical microscopy (OM). We found that the delta-ferrite microstructure size decreased when preheating time was increased at 1295 oC, and that the delta-ferrite content could be controlled through preheating. Potentiodynamic polarization test were carried out in NaCl (0.5 M) + H2SO4 (0.5 M) solution, and it was found that higher delta-ferrite content resulted in less corrosion potential and passive potential. To determine the cause, an analysis was conducted using energy-dispersive spectroscopy (EDS), which confirmed that higher delta-ferrite content led to weaker corrosion resistance, due to Cr degradation at the delta-ferrite and austenite boundaries. The degradation of Cr on the boundaries between austenite and delta-ferrite can be explained by the difference in the diffusion coefficient of Cr in the ferrite and austenite. A scanning electron microscopy (SEM) analysis of material used for actual semiconductor piping confirmed that corrosion begins at the delta-ferrite and austenite boundaries. These results confirm the need to control delta-ferrite content in AISI 316L stainless steel used for semiconductor piping.

scholarly journals Obtaining the conductive SnO2 films by chemical bath deposition method

2019 ◽  
Vol 60 (11) ◽  
pp. 1-10
Author(s):  
Vladislav I. Rogozin ◽  
◽  
Vyacheslav F. Markov ◽  
Larisa N. Maskaeva ◽  
Anastasia E. Krasovskaya ◽  
...  
Keyword(s):  
Tin Dioxide ◽  
Solid Phase ◽  
Average Particle Size ◽  
Ammonium Fluoride ◽  
Contact Layer ◽  
Average Particle ◽  
Solution Ph ◽  
Before And After ◽  
Initial Salt ◽  
Conductive Properties

Thanks to such unique properties as transparency and conductivity tin dioxide often utilize as transparent contact layer to produce displays, solar cells, and sensor devices. Hydrochemical method of deposition SnO2 films is a perspective due to its simplicity, and economical efficiency. The ionic equilibria analysis was carried out and the boundary conditions of Sn(OH)2 solid phase formation in the «Sn2+ – H2O – OH‾» system calculated. It was established, that tin(II) hydroxide may be obtain in the range 2 < pH < 12. Preliminary results allow to determinate an optimal mixture sourness interval 1 < pH < 5. Revealed, that the thickness of the Sn(OH)2 films strongly depends on the solution pH. Maximum value of 488 nm reached at pH = 8. Conductive SnO2 layers were obtained on a glass and sitall substrates with simultaneously presence of antimony chloride and ammonium fluoride followed by annealing in air. The thickness vs temperature and thickness vs tin initial salt concentration dependences were installed. The uniform tin hydroxide layers with a thickness of ~74 nm may be synthesized under pH = 2 conditions. By the electron microscopy method the average particle size was established changing from 200 to 400 nm for as-synthesized films, to ~20 nm for annealed which indicates the nanostructure nature of the films. The morphology, elemental composition and conductive properties of deposited films were investigated before and after heating stage. Studying the annealing temperature influence at the film resistance were identified a three temperature ranges within which the films sharply differ in their conductive properties, which is associated with phase and structural transformations in them. Shown, that the most conductive SnO2 films with the omic resistance 3-5 kOm/sm were obtained at the temperature range 620-870 K.

scholarly journals A 2.9 GPa Strength Nano-Grained and Nano-Precipitated 304L-Type Austenitic Stainless Steel

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5382
Author(s):  
Congcong Du ◽  
Guoying Liu ◽  
Baoru Sun ◽  
Shengwei Xin ◽  
Tongde Shen
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Yield Strength ◽  
Average Particle Size ◽  
Coarse Grained ◽  
Average Particle ◽  
Dispersion Strengthening ◽  
Ultrafine Grained ◽  
Average Grain Size ◽  
Bulk Nanocrystalline

Austenitic stainless steel has high potential as nuclear and engineering materials, but it is often coarse grained and has relatively low yield strength, typically 200–400 MPa. We prepared a bulk nanocrystalline lanthanum-doped 304L austenitic stainless steel alloy by a novel technique that combines mechanical alloying and high-pressure sintering. The achieved alloy has an average grain size of 30 ± 12 nm and contains a high density (~1024 m−3) of lanthanum-enriched nanoprecipitates with an average particle size of approx. 4 nm, leading to strong grain boundary strengthening and dispersion strengthening effects, respectively. The yield strength of nano-grained and nano-precipitated stainless steel reaches 2.9 GPa, which well exceeds that of ultrafine-grained (100–1000 nm) and nano-grained (<100 nm) stainless steels prepared by other techniques developed in recent decades. The strategy to combine nano-grain strengthening and nanoprecipitation strengthening should be generally applicable to developing other ultra-strong metallic alloys.

Impacts of Acid Treatment on the Characteristics of Native Corn Starch Granules

2011 ◽  
Vol 221 ◽  
pp. 72-77 ◽  
Author(s):  
Xin Jin ◽  
Shuan Qing Hou ◽  
Xiao Xu Sha ◽  
Liang Yu
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Acid Treatment ◽  
Corn Starch ◽  
Average Particle Size ◽  
Peak Temperature ◽  
Average Particle ◽  
Starch Granules ◽  
Acid Modification ◽  
Before And After

Native corn starches were acid-treated at 53 °C for hours in HCl aqueous solution. The peak temperature (Tp) and heat of gelatinization (ΔHgel) before and after treatments were determined. The average particle size, TG and viscosity were measured. The results showed that the viscosity of corn starch decreased from 630mPa to 4.6mPa after acid treatment for 6h. The average particle size decreased and ΔHgel decreased obviously after acid modification.

scholarly journals Analysis of The Migration and Accumulation Process of Nitrate-nitrogen Pollutants in The Unsaturated Zone of Soil

2021 ◽  
Vol 293 ◽  
pp. 01004
Author(s):  
Xiangcai Li ◽  
Ping Jing
Keyword(s):  
Unsaturated Zone ◽  
Maximum Concentration ◽  
North China ◽  
Nitrate Nitrogen ◽  
Average Particle Size ◽  
Soil Layer ◽  
Average Particle ◽  
Migration Process ◽  
The Difference ◽  
Nitrogen Pollutants

In order to understand the migration process of nitrate-nitrogen pollutants in the shallow unsaturated zone of the soil, the Tianjin coastal dredger and typical fluvo-aquic soils in North China were used as the research objects. The Hydrus-1D software was used to establish a numerical model to simulate nitrate. The pollution process of nitrogen pollutants in the unsaturated zone of soil, the results show that: during the migration process of the two kinds of shallow vadose zones of soil, the nitrate-nitrogen pollutants migrate downward at the maximum concentration before reaching the maximum concentration. After the maximum concentration, the concentration of nitrate nitrogen in the soil no longer increases; due to the difference in the average particle size of the soil, the migration rate of nitrate nitrogen in fluvo-aquic soil is significantly greater than that in artificial dredger soil. Nitrate nitrogen is in the simulation period completely passing through the simulated soil layer, the fluvo-aquic soil is completely passed through by nitrate nitrogen at 2d, and the artificial dredge fill is completely passed through by nitrate nitrogen at 2.5d.

scholarly journals Acoustic Properties of 316L Stainless Steel Lattice Structures Fabricated via Selective Laser Melting

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 111 ◽  
Author(s):  
Xiaojing Sun ◽  
Fengchun Jiang ◽  
Jiandong Wang
Keyword(s):  
Stainless Steel ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Sound Absorption ◽  
316L Stainless Steel ◽  
Acoustic Properties ◽  
Sound Insulation ◽  
Frequency Range ◽  
Laser Melting ◽  
The Difference

A bulk specimen and two different lattice sandwich structures composed of 316L stainless steel were fabricated via selective laser melting. This study analysed the acoustic properties, including sound insulation and sound absorption, of the three kinds of structures, which were produced via selective laser melting under the same process parameters. The results showed that the difference in the unit structures, rather than microstructural difference, was the main reason for the difference in acoustic properties between the samples. Under the same process parameters, the microstructure of the different structures had the same cell structure. However, the sound absorption properties of the lattice sandwich structures were better than those of the bulk sample in the measured frequency range of 1–6.3 kHz. The lattice sandwich structure with 2.5 × 2.5 × 2.5 mm3 unit structures exhibited excellent sound insulation properties in the frequency range of 1–5 kHz.

scholarly journals Accelerated corrosion performance of AISI 316L stainless steel concrete reinforcement used in restoration works of ancient monuments

2018 ◽  
Vol 188 ◽  
pp. 03003 ◽  
Author(s):  
Sofia Tsouli ◽  
Angeliki G. Lekatou ◽  
Evangelos Siozos ◽  
Spyridon Kleftakis
Keyword(s):  
Stainless Steel ◽  
316L Stainless Steel ◽  
Salt Spray ◽  
Localized Corrosion ◽  
Corrosion Performance ◽  
Cyclic Polarization ◽  
Accelerated Corrosion ◽  
Before And After ◽  
Ancient Monuments ◽  
Steel Rebars

The accelerated corrosion performance of AISI type 316L stainless steel rebars in solutions simulating concrete exposed to various environments was studied by means of cyclic polarization, before and after a four month salt spray test. B500A structural steel rebars were also tested for comparison reasons. Although 316L showed some susceptibility to localized corrosion during polarization in saturated Ca(OH)2containing 3.5 wt.% NaCl, four months of salt spraying did not significantly affect its polarization behavior. Salt spraying for 4 m did not have any significant effect on the macrostructural state of 316L reinforced concrete.

scholarly journals Improving the CO and CH4 Gas Sensor Response at Room Temperature of α-Fe2O3(0001) Epitaxial Thin Films Grown on SrTiO3(111) Incorporating Au(111) Islands

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 848
Author(s):  
Aída Serrano ◽  
Jesús López-Sánchez ◽  
Iciar Arnay ◽  
Rosalía Cid ◽  
María Vila ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Gas Sensing ◽  
Structural Characteristics ◽  
Average Particle Size ◽  
Average Particle ◽  
Epitaxial Thin Films ◽  
Before And After ◽  
Crystallographic Axes ◽  
Gas Exposure

In this work, the functional character of complex α-Fe2O3(0001)/SrTiO3(111) and Au(111) islands/α-Fe2O3(0001)/SrTiO3(111) heterostructures has been proven as gas sensors at room temperature. Epitaxial Au islands and α-Fe2O3 thin film are grown by pulsed laser deposition on SrTiO3(111) substrates. Intrinsic parameters such as the composition, particle size and epitaxial character are investigated for their influence on the gas sensing response. Both Au and α-Fe2O3 layer show an island-type growth with an average particle size of 40 and 62 nm, respectively. The epitaxial and incommensurate growth is evidenced, confirming a rotation of 30° between the in-plane crystallographic axes of α-Fe2O3(0001) structure and those of SrTiO3(111) substrate and between the in-plane crystallographic axes of Au(111) and those of α-Fe2O3(0001) structure. α-Fe2O3 is the only phase of iron oxide identified before and after its functionalization with Au nanoparticles. In addition, its structural characteristics are also preserved after Au deposition, with minor changes at short-range order. Conductance measurements of Au(111)/α-Fe2O3(0001)/SrTiO3(111) system show that the incorporation of epitaxial Au islands on top of the α-Fe2O3(0001) layer induces an enhancement of the gas-sensing activity of around 25% under CO and 35% under CH4 gas exposure, in comparison to a bare α-Fe2O3(0001) layer grown on SrTiO3(111) substrates. In addition, the response of the heterostructures to CO gas exposure is around 5–10% higher than to CH4 gas in each case.

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