Influence of Processing Factors on the Surface Properties of Zirconia Coatings Fabricated by Room Temperature Spray Process

Highly roughened surfaces on dental implants enhance the bone-bonding ability and in vivo cell adhesion on the implant surface. In this study, zirconia substrates were coated by powder coating using room temperature spray processing to improve their surface properties. Processing factors (particle size of the starting powder, number of repetitions of the deposition cycle, and spraying distance) were controlled to form a dense coating layer with high surface roughness on the zirconia substrate. Starting zirconia powders for coating were heat-treated at high temperature to control the particle size and kinetic energy. The coating layer fabricated from starting powder with a particle size of about 1.52 μm shows a homogeneous and dense microstructure, and it has a maximum surface roughness about 0.37 μm. The surface roughness of the film coatings increased with the number of times that the deposition cycle was repeated. No phase changes between the starting powder and the coating layer were observed, and all of the materials show identical tetragonal phases.

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Effect of Optical and Morphological Control of Single-Structured LEC Device

Micromachines ◽

10.3390/mi12070843 ◽

2021 ◽

Vol 12 (7) ◽

pp. 843

Author(s):

Woo Jin Jeong ◽

Jong Ik Lee ◽

Hee Jung Kwak ◽

Jae Min Jeon ◽

Dong Yeol Shin ◽

...

Keyword(s):

Heat Treatment ◽

Surface Roughness ◽

Surface Properties ◽

High Efficiency ◽

High Surface ◽

Reduction Rate ◽

Operating Characteristics ◽

Emission Layer ◽

Light Emitting ◽

Stable Operating

We investigated the performance of single-structured light-emitting electrochemical cell (LEC) devices with Ru(bpy)3(PF6)2 polymer composite as an emission layer by controlling thickness and heat treatment. When the thickness was smaller than 120–150 nm, the device performance decreased because of the low optical properties and non-dense surface properties. On the other hand, when the thickness was over than 150 nm, the device had too high surface roughness, resulting in high-efficiency roll-off and poor device stability. With 150 nm thickness, the absorbance increased, and the surface roughness was low and dense, resulting in increased device characteristics and better stability. The heat treatment effect further improved the surface properties, thus improving the device characteristics. In particular, the external quantum efficiency (EQE) reduction rate was shallow at 100 °C, which indicates that the LEC device has stable operating characteristics. The LEC device exhibited a maximum luminance of 3532 cd/m2 and an EQE of 1.14% under 150 nm thickness and 100 °C heat treatment.

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Surface Modification of Ti Dental Implants by Grit-Blasting and Micro-Arc Oxidation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.47-50.467 ◽

2008 ◽

Vol 47-50 ◽

pp. 467-470 ◽

Cited By ~ 1

Author(s):

Yeon Wook Kim

Keyword(s):

Surface Roughness ◽

Dental Implants ◽

High Surface ◽

Titanium Implants ◽

Osteoblastic Cell ◽

Implant Surface ◽

Oxidation Treatment ◽

Grit Blasting ◽

Micro Arc Oxidation ◽

Titanium Dental Implants

The osseointegration capability of titanium dental implants is related to their chemical composition and surface roughness. In this study, the combination of grit-blasting and micro-arc oxidation had been used for producing the improved implant surfaces. The ceramic particles were projected to titanium dental implants through a nozzle at high velocity by means of compressed air to get high surface roughness. Then the surface of titanium implants was modified by micro-arc oxidation treatment. The current density, frequency and duty were 50-300 mA/cm2, 100 Hz, and 50%, respectively. A porous TiO2 layer was formed on the surface after the oxidation treatment. The surface structure of oxidized implants exhibited nanometer-sized pores with an average diameter of 0.2 µm. The TiO2 passive layer of the implant surface can attribute to the excellent biocompatibility. The high roughness (Ra=0.182 µm) formed by grit-blasting maximizes the interlocking between mineralized bone and the surface of the implant. Surface roughness in the manometer range formed by micro-arc oxidation treatment would play an important role in the adsorption of proteins, adhesion of osteoblastic cell and thus the rate of osseointegration.

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A Study on Hermetic Glass Sealing Using a Modified Direct Bonding Method

MRS Proceedings ◽

10.1557/proc-444-123 ◽

1996 ◽

Vol 444 ◽

Author(s):

B. K. Ju ◽

C. G. Ko ◽

Y. H. Lee ◽

I. B. Kang ◽

P. White ◽

...

Keyword(s):

Surface Roughness ◽

Room Temperature ◽

High Surface ◽

Chemical Species ◽

Interface Energy ◽

Hydroxyl Groups ◽

Glass Wafer ◽

Post Annealing ◽

Main Factors ◽

Bonding Method

AbstractThis paper presents the process and experimental results about the improved initial bonding between #7740 glass and silicon wafers. We employed a modified initial bonding procedure, called by water-enhanced direct bonding(WDB) technique, and could obtain large initially-bonded area(≥ 95% of the whole wafer area) at room temperature and high interface energy (≥ 2,000 erg/cm2) through 250 °C post-annealing even though the glass wafer had high surface roughness. The main factors contributing to the wider bonded area and higher interface energy in the developed WDB process could be inferred the increase of chemical species (oxygen and hydroxyl groups) responsible for initial hydrogen bonding and conversion from hydroxyl bonds to siloxane bonds in the temperature range between room temperature and 250 °C.

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Changes in Bond Strength and Topography for Y-TZP Etched with Hydrofluoric Acid Depending on Concentration and Temperature Conditions

Medicina ◽

10.3390/medicina56110568 ◽

2020 ◽

Vol 56 (11) ◽

pp. 568

Author(s):

Hyo-Eun Kim ◽

Myung-Jin Lim ◽

Mi-Kyung Yu ◽

Kwang-Won Lee

Keyword(s):

Surface Roughness ◽

Bond Strength ◽

Hydrofluoric Acid ◽

Room Temperature ◽

High Surface ◽

Tetragonal Zirconia ◽

Resin Cement ◽

Grain Structure ◽

Temperature Conditions ◽

Significant Difference

Background and objectives: This study aimed to investigate the change in bond strength between resin cement and tetragonal zirconia polycrystalline stabilized with 3 to 8 mol% yttrium oxide (Y-TZP) and observe the topographical change of the Y-TZP surface when etched with hydrofluoric acid (HF) solution under different concentration and temperature conditions. Materials and Methods: Non-etched sintered Y-TZP specimens under two different temperature conditions (room temperature and 70–80 °C, respectively), were used as a control, while experimental groups were etched with 5%, 10%, 20%, and 40% HF solutions for 10 min. After zirconia primer and MDP-containing resin cement were applied to the Y-TZP surface, the shear bond strength (SBS) of each experimental group was measured. Results: Under room temperature conditions, the highest SBS value was measured in the 40% HF etching group, representing a significant deviation from the other groups (p < 0.05). In the 70–80 °C tests, the 40% HF etching group also had the highest SBS value, but there was no significant difference when compared to the 20% HF etching group (p > 0.05). From SEM and AFM observations, the HF solution increasingly dissolved the Y-TZP surface grain structure as the concentration and application temperature rose, resulting in high surface roughness and irregularities. Conclusions: Pretreating with either 20% HF solution at 70–80 °C or 40% HF solution at room temperature and 70–80 °C effectively acid etched the Y-TZP surface, resulting in more surface roughness and irregularities. Accounting for the concentration and temperature conditions of the HF solution, using 40% HF solution at room temperature will result in improvements in adhesion between resin cement and Y-TZP.

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INVESTIGATION OF THE EFFECTS OF DIFFERENT RETROGRESSION AND RE-AGING PARAMETERS APPLIED TO THE 7075 ALLOY ON THE MICRO-ARC OXIDATION PROCESS

Surface Review and Letters ◽

10.1142/s0218625x21500785 ◽

2021 ◽

Vol 28 (09) ◽

pp. 2150078

Author(s):

MUSTAFA SAFA YILMAZ ◽

GÖKHAN ÖZER ◽

ORHAN ŞAHIN ◽

AHMET KARAASLAN

Keyword(s):

Surface Roughness ◽

Corrosion Resistance ◽

Surface Properties ◽

Anode Voltage ◽

Coating Layer ◽

Surface Hardness ◽

Process Time ◽

Cathode Voltage ◽

Open Time ◽

Micro Arc Oxidation

In this paper, retrogression and re-aging (RRA) heat treatment was applied to 7075 aluminum alloy in T6 condition at different times (30 and 90[Formula: see text]min) and temperatures (180∘C and 240∘C). While RRA heat treatments increase the corrosion resistance of the material, it does not harm its mechanical properties. On the other hand, the surface resistance of aluminum is low. Surface modifications are applied to overcome this deficiency. Among these, the micro-arc oxidation (MAO) method increases the corrosion resistance and attains excellent values in surface hardness. To better understand the RRA/MAO relationship, heat-treated (RRA) samples with four different parameters were coated with the MAO method. In this way, a ceramic oxide coating layer was created on the material surfaces. In order to determine the RRA parameter effect, the MAO process parameters are kept constant (anode voltage ([Formula: see text]): 500[Formula: see text]V, cathode voltage ([Formula: see text]): 300[Formula: see text]V, anode voltage open time ([Formula: see text]: 300[Formula: see text][Formula: see text]s, cathode voltage open time ([Formula: see text]): 200[Formula: see text][Formula: see text]s, frequency: 160 coating with Hz, and process time: 20[Formula: see text]min). Surface properties (coating thickness, surface roughness, surface arc duct’s structure, etc.), phase analysis (X-ray diffraction (XRD)) and microstructures (coating cross-section studies: distance-dependent hardness, coating/backing material interface character, coating porosity ratio) were examined. XRD analysis showed that the main phase of the coatings is [Formula: see text]-Al2O3. A coating layer of around 125[Formula: see text][Formula: see text]m was achieved with the growth rate of 6[Formula: see text][Formula: see text]m/min. Surface roughness was between 5.5[Formula: see text][Formula: see text]m and 8[Formula: see text][Formula: see text]m for different RRA parameters. RRA/MAO relation with the characterization made was detailed, and predictions were made for the surface properties of the material (hardness, corrosion resistance, wear, etc.).

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Impact of medical titanium implant surface on the efficiency of fibrointegration

Стоматология для всех ◽

10.35556/idr-2020-2(91)50-55 ◽

2020 ◽

pp. 50-55

Author(s):

T. R. Davydova ◽

А. I. Shaikhaliev ◽

D. A. Usatov ◽

G. A. Gasanov ◽

R. S. Korgoloev

Keyword(s):

Surface Roughness ◽

Titanium Dioxide ◽

Rough Surface ◽

Soft Tissues ◽

Titanium Implant ◽

Implant Surface ◽

Anatase Structure ◽

Bioactive Coating ◽

Cell Structures ◽

Titanium Alloy Ti6al4v

The aim of this study was to study the effect of surface branching of titanium endoprostheses on the efficiency of fibrointegration. The object of the study was samples of titanium alloy Ti6Al4V in the form of disks with a diameter of 5 mm and a thickness of 1 mm with various surface treatments: 1) samples with a rough surface after sandblasting; 2) samples with a rough surface after sandblasting with a bioactive coating of titanium dioxide TiO2 with anatase structure. The study of surface roughness was carried out by profilometry. Evaluation of the spreading and proliferation of cells on the surface of test samples, as well as evaluation of the effectiveness of fibrointegration was carried out according to standard methods using scanning electron microscopy. During the experiments, mesinchymal stem cells were sown on test samples and the test samples were introduced into the soft tissues of experimental animals. Based on the results obtained, it was concluded that the technology of forming rough surfaces by sandblasting does not provide high uniformity and reproducibility in the nanometer range and, apparently, another method for obtaining a rough surface should be chosen. The application of a bioactive coating of titanium dioxide TiO2 with the anatase structure to the surface of titanium endoprostheses increases the efficiency of fibrointegration, however, primarily the fibrointegration of titanium endoprostheses depends on their surface roughness, which determines the concentration of cell structures, the intensity of their adhesion and the ability to fibrointegrative process.

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Understanding Sulfur Redox Mechanisms in Different Electrolytes for Room-Temperature Na–S Batteries

Nano-Micro Letters ◽

10.1007/s40820-021-00648-w ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Hanwen Liu ◽

Wei-Hong Lai ◽

Qiuran Yang ◽

Yaojie Lei ◽

Can Wu ◽

...

Keyword(s):

Room Temperature ◽

High Surface ◽

Reversible Capacity ◽

High Loading ◽

Side Reactions ◽

Liquid Sulfur ◽

Shuttle Effect ◽

Loading Ratio ◽

Solid Liquid ◽

Sulfur Cathodes

Abstract This work reports influence of two different electrolytes, carbonate ester and ether electrolytes, on the sulfur redox reactions in room-temperature Na–S batteries. Two sulfur cathodes with different S loading ratio and status are investigated. A sulfur-rich composite with most sulfur dispersed on the surface of a carbon host can realize a high loading ratio (72% S). In contrast, a confined sulfur sample can encapsulate S into the pores of the carbon host with a low loading ratio (44% S). In carbonate ester electrolyte, only the sulfur trapped in porous structures is active via ‘solid–solid’ behavior during cycling. The S cathode with high surface sulfur shows poor reversible capacity because of the severe side reactions between the surface polysulfides and the carbonate ester solvents. To improve the capacity of the sulfur-rich cathode, ether electrolyte with NaNO3 additive is explored to realize a ‘solid–liquid’ sulfur redox process and confine the shuttle effect of the dissolved polysulfides. As a result, the sulfur-rich cathode achieved high reversible capacity (483 mAh g−1), corresponding to a specific energy of 362 Wh kg−1 after 200 cycles, shedding light on the use of ether electrolyte for high-loading sulfur cathode.

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Geometric correction for thermographic images of asteroid 162173 Ryugu by TIR (thermal infrared imager) onboard Hayabusa2

Earth Planets and Space ◽

10.1186/s40623-021-01437-w ◽

2021 ◽

Vol 73 (1) ◽

Author(s):

Takehiko Arai ◽

Tatsuaki Okada ◽

Satoshi Tanaka ◽

Tetsuya Fukuhara ◽

Hirohide Demura ◽

...

Keyword(s):

Surface Roughness ◽

High Surface ◽

Thermal Inertia ◽

Thermal Infrared ◽

Shape Model ◽

Infrared Imager ◽

Least Squares Fit ◽

Temperature Maps ◽

Pixel Scale ◽

Thermal Infrared Imager

AbstractThe thermal infrared imager (TIR) onboard the Hayabusa2 spacecraft performed thermographic observations of the asteroid 162173 Ryugu (1999 JU$$_3$$ 3 ) from June 2018 to November 2019. Our previous reports revealed that the surface of Ryugu was globally filled with porous materials and had high surface roughness. These results were derived from making the observed temperature maps of TIR using a projection method onto the shape model of Ryugu as geometric corrections. The pointing directions of TIR were calculated using an interpolation of data from the SPICE kernels (NASA/NAIF) during the periods when the optical navigation camera (ONC) and the light detection and ranging (LIDAR) observations were performed. However, the mapping accuracy of the observed TIR images was degraded when the ONC and LIDAR were not performed with TIR. Also, the orbital and attitudinal fluctuations of Hayabusa2 increased the error of the temperature maps. In this paper, to solve the temperature image mapping problems, we improved the correction method by fitting all of the observed TIR images with the surface coordinate addressed on the high-definition shape model of Ryugu (SFM 800k v20180804). This correction adjusted the pointing direction of TIR by rotating the TIR frame relative to the Hayabusa2 frame using a least squares fit. As a result, the temperature maps spatially spreading areas were converged within high-resolved $$0.5^\circ$$ 0 . 5 ∘ by $$0.5^\circ$$ 0 . 5 ∘ maps. The estimated thermal inertia, for instance, was approximately 300$$\sim$$ ∼ 350 Jm$$^{-2}$$ - 2 s$$^{-0.5}$$ - 0.5 K$$^{-1}$$ - 1 at the hot area of the Ejima Saxum. This estimation was succeeded in case that the surface topographic features were larger than the pixel scale of TIR. However, the thermal inertia estimation of smooth terrains, such as the Urashima crater, was difficult because of surface roughness effects, where roughness was probably much smaller than the pixel scale of TIR.

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Mechanical Characterization and Thermodynamic Analysis of Laser-Polished Landscape Design Products Using 3D Printing

Materials ◽

10.3390/ma14102601 ◽

2021 ◽

Vol 14 (10) ◽

pp. 2601

Author(s):

Yue Ba ◽

Yu Wen ◽

Shibin Wu

Keyword(s):

Surface Roughness ◽

3D Printing ◽

Fused Deposition Modeling ◽

High Surface ◽

Landscape Design ◽

Laser Polishing ◽

Fused Deposition ◽

Design Structure ◽

3D Printed ◽

Stability And Accuracy

Recent innovations in 3D printing technologies and processes have influenced how landscape products are designed, built, and developed. In landscape architecture, reduced-size models are 3D-printed to replicate full-size structures. However, high surface roughness usually occurs on the surfaces of such 3D-printed components, which requires additional post-treatment. In this work, we develop a new type of landscape design structure based on the fused deposition modeling (FDM) technique and present a laser polishing method for FDM-fabricated polylactic acid (PLA) mechanical components, whereby the surface roughness of the laser-polished surfaces is reduced from over Ra 15 µm to less than 0.25 µm. The detailed results of thermodynamics and microstructure evolution are further analyzed during laser polishing. The stability and accuracy of the results are evaluated based on the standard deviation. Additionally, the superior tensile and flexural properties are examined in the laser-polished layer, in which the ultimate tensile strength (UTS) is increased by up to 46.6% and the flexural strength is increased by up to 74.5% compared with the as-fabricated components. Finally, a real polished landscape model is simulated and optimized using a series of scales.

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Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽

10.3390/ma14061376 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1376

Author(s):

Alex Quok An Teo ◽

Lina Yan ◽

Akshay Chaudhari ◽

Gavin Kane O’Neill

Keyword(s):

Surface Roughness ◽

Stainless Steel ◽

Surface Characterization ◽

High Surface ◽

Surface Characteristics ◽

Post Processing ◽

Stainless Steel 316L ◽

Processing Methods ◽

Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

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