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Advances in Coatings Deposition and Characterization

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Nguyễn Gia Hào

Academic year: 2023

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Abstract: The axial injection of the suspension in the atmospheric plasma spraying process (here called axial suspension plasma spraying) is an attractive and advanced thermal spraying technology specifically for the deposition of thermal barrier coatings (TBCs). Thus, the following equation was used to calculate the indentation fracture toughness of the top layers.

Table 1. Spray parameters used for YSZ top coats.
Table 1. Spray parameters used for YSZ top coats.

Results and Discussion

The porosity of the upper layers increases with the increase in the bond layer roughness (Samples C and D in Figure 2c). The deposition efficiency of the upper layers is significantly reduced at the higher spacing distance (compare Figures 2b and 4b).

Figure 1. Cross-section SEM image of as sprayed YSZ top coats (Samples A, B, C, and D) deposited at a standoff distance of 70 mm, on BC with different surface treatments: (a) mirror polishing; (b) grinding;
Figure 1. Cross-section SEM image of as sprayed YSZ top coats (Samples A, B, C, and D) deposited at a standoff distance of 70 mm, on BC with different surface treatments: (a) mirror polishing; (b) grinding;

Conclusions

Comparative study of suspension-sprayed and high-velocity oxy-fuel sprayed YSZ thermal barrier coatings.Surf. Influence of microstructure on the thermal properties of plasma sprayed axial suspension YSZ thermal barrier coatings.J.

Sputtering Physical Vapour Deposition (PVD)

Coatings: A Critical Review on Process Improvement and Market Trend Demands

Introduction

This process causes a change in the properties of the surface and the transition zone between the substrate and the deposited material. On the other hand, the properties of the films can also be influenced by the properties of the substrate.

PVD Coatings

This plasma passes through the deposition chamber and is stronger in the middle position of the reactor. In addition, in MS deposition processes, usually three quarters of the total energy is consumed in the coating step.

Figure 2. Schematic drawing of two conventional PVD processes: (a) sputtering and (b) evaporating using ionized Argon (Ar+) gas.
Figure 2. Schematic drawing of two conventional PVD processes: (a) sputtering and (b) evaporating using ionized Argon (Ar+) gas.

Sputtering Depositions Improvements

Its efficiency can reduce costs and improve film properties, with the rotation speed determining the deposition sequence of the layer. Studies have shown that this effect is reflected in the morphological properties of the coated substrates [60,71,78]. Emerging technologies allow an increase of about 30% in the ionization rate and higher charge states of the target ions.

Studies show a great interest in using the HiPIMS technique due to its versatility in the production of the PVD coating. 100] showed that it is possible to increase the deposition rate by directing the ion current towards the substrate by applying an external magnetic field using a solenoid coil excited with a DC pulse. However, to achieve higher deposition rates than DCMS, the positioning of the substrates must be planned in the center of the reactor, where the deposition rate is more effective.

The use of the sputtering technique in the industrial context applied in the production of solar cells was demonstrated. With this study it was possible to propose a modification of the reactor geometry for a better gas flow over the substrate.

Figure 6. Schematic comparison between (a) conventional magnetron sputtering (MS), and the (b) plasma enhanced magnetron sputtering (PEMS) assisted process
Figure 6. Schematic comparison between (a) conventional magnetron sputtering (MS), and the (b) plasma enhanced magnetron sputtering (PEMS) assisted process

Concluding Remarks

HiPIMS High Power Impulse Magnetron Sputtering HPMS High Power Pulsed Magnetron Sputtering MEP Magnetically Enhanced Plasma. Effect of nitrogen-argon flow ratio on the microstructural and mechanical properties of AlSiN thin films prepared by high-power pulse magnetron sputtering.Surf. Influence of N2/Ar flow ratio on microstructure and properties of AlCrSiN coatings deposited by high power pulsed magnetron sputtering.Coatings2018, 8, 3.

Cr1−xAlx)N: A comparison of direct current, pulsed intermediate frequency, and high power pulsed magnetron sputtering for injection molding components. Thin solid films. Effect of microstructure on mechanical and tribological properties of TiAlSiN nanocomposite coatings deposited by modulated pulsed power magnetron sputtering. Thin solid films. The enhancement of powerful magnetron sputtering performance by an external unbalanced magnetic field.Vacuum.

Synergistic enhancement effect between external electric and magnetic fields during high-power pulsed magnetron sputtering discharge. Vacuum. Neutral gas simulation of the influence of rotating spokes on rare gas fraction in high power pulse magnetron sputtering. Contribution.

Combination of Electrodeposition and Transfer Processes for Flexible Thin-Film

Thermoelectric Generators

Experimental Section

The power measurement method of flexible thin-film thermoelectric generators is described in Section 3.3. After fabricating flexible thin-film generators, we calculated the electrical resistance of the generators based on the thermoelectric properties of n-type and p-type thin films. The thickness of the type 3 generator was 0.6 mm, which is the same as the type 2 generator.

We initially measured the total resistance (Rtotal) of the flexible thin film thermoelectric generators, as listed in Table 2. The total value of the Type 1 generator was not measured because the rectangular thin films were partially broken during the transfer process. At a temperature difference of 60 K, the Voc values ​​of the Type 2 and Type 3 generators were 9.4 and 22.4 mV, respectively.

The maximum output power (Pmax) of the flexible thin-film thermoelectric generators as a function of temperature change is shown in Figure 5. On the other hand, the Pmax value of the type 3 generator was drastically improved. Pmax increased exponentially with an increase in temperature difference.

Table 1. In-plane thermoelectric properties of the n- and p-type thin films.
Table 1. In-plane thermoelectric properties of the n- and p-type thin films.

Experimental 1. Materials and Methods

The relative humidity of Shanghai during the spray deposition of the perovskite films was in the range of 35% to 50% in different days. Average thickness and roughness of the films were measured by a stylus profilometer (KLA-Tencor P7, Milpitas, CA, USA). The conversion of the MAI and PBCL2PRECURSors to mixed halide perovskite and the absorption of the perovskite films were evaluated by X-ray diffraction (XRD, Model D5005, Bruker, Billerica, MA, USA) and UV-Vis absorption spectrophotometers, MA) (EV300, thermo Fishermo Fisherficcer, Waltham, MA, EV300, Ther ivelief.

Figure 3a shows a decrease in the surface tension of the perovskite solution with the solution concentration. On the other hand, examination of the perovskite solution droplets on glass substrates shows that the contact angle increases with concentration (Figure 3b). High concentration of the perovskite solution can cause the formation of larger crystals in the film and therefore surface dewetting, i.e. crystallization dewetting [2], which naturally leads to the formation of rough film with pinholes (Figure 4).

Figure 7 shows the measured thickness and roughness values ​​of the perovskite layers, sputtered using 40, 70 and 100 passes, on substrates kept at ambient temperature. Figure 11d is a view of the fabricated film (5×5 cm2), made using the optimal conditions of 100 sputter passes deposited on the hot plate held at 150◦C, using a perovskite solution concentration of 10 wt.%.

Figure 2. (a) schematic of the spray coating process and the aparatus. (b) picture of the Holmarc spray coating system, which accomodates the spray nozzle and the hotplate shown in (a).
Figure 2. (a) schematic of the spray coating process and the aparatus. (b) picture of the Holmarc spray coating system, which accomodates the spray nozzle and the hotplate shown in (a).

Antireflection Coatings for Strongly Curved Glass Lenses by Atomic Layer Deposition

Materials and Methods

Applying these two corrections, the design and coating reflectance are in excellent agreement for a sample that is placed in the center of the substrate table, see Figure 4a. The area between the dotted lines in Figure 4b shows the worst-case error corridor of the maximum possible deviations calculated from the theoretical reflectance spectrum. The measured reflectance spectra of sample 2 lie within the worst-case error corridor, indicating that the small deviations in the AR pattern are most likely a consequence of the non-uniformity of the lateral layer thickness in the substrate table.

The refractive index of the lens was calculated from the measured reflectance spectra of the uncoated hemispherical lens, which is slightly higher than the reflectance of the silica glass substrate, see Fig. 5a. The AR performance of a coated lens depends on the position in the chamber due to lateral thickness non-uniformity. The first part of the coating design is based on the patented AR-hard® (Jena, Germany).

Comparable reflectance spectra over the entire lens surface under normal light conditions are a result of the very good conformance of ALD coatings. Influence of the oxygen plasma parameters on the atomic layer deposition of titanium dioxide.Nanotechnology.

Table 1. Process parameter for depositing SiO 2 , Al 2 O 3 , TiO 2 and Ta 2 O 5 ALD thin films.
Table 1. Process parameter for depositing SiO 2 , Al 2 O 3 , TiO 2 and Ta 2 O 5 ALD thin films.

Continuous Tip Widening Technique for Roll-to-Roll Fabrication of Dry Adhesives

However, this method has a disadvantage; cannot precisely control tip thickness or size. In particular, in the roll-to-roll process, which can only use a flexible polymer mold, tip breakage during disassembly becomes apparent. The device is equipped with a load cell capable of measuring the load in the z-axis direction, allowing the measurement of tensile force including preload.

Figure 1 shows the schematic of the two-step UV-assisted CFL and that of a continuous production device. The tip of the microstructure was broadened simply by using a glass substrate, and the low adhesion between glass and PUA enabled the production of a mushroom structure without any surface treatment. After appropriate pressurization, the mushroom structure was fabricated by a second exposure and the tensile strength of the sample was measured by a typical adhesion measurement.

After using the test for 5000 cycles, the dry adhesive and substrate surfaces were cleaned with a commercially available pressure-sensitive adhesive tape. The subsequent 5,000 additional adhesion tests resulted in the same level of adhesion of the contaminants and additional defects.

Figure 1. Schematic of the continuous fabrication process for mushroom-shaped dry adhesives and procedure for mushroom-shaped structures via two-step UV molding process.
Figure 1. Schematic of the continuous fabrication process for mushroom-shaped dry adhesives and procedure for mushroom-shaped structures via two-step UV molding process.

Preparation and Characterization of Bioplastics from Grass Pea Flour Cast in the Presence of

Microbial Transglutaminase

Materials and Methods 1. Materials

The films prepared in the absence and presence of mTGase were subjected to a three-step in vitro digestion using adult model [18–20] under simulated oral, gastric and duodenal physiological conditions. Panel B-SDS-PAGE of solubilized films cast in the absence (lane 1) and presence (lane 2) of mTGase. As shown in Table 2, grass pea-based films cast in the absence of mTGase have an opacity value of 7.74±0.26 A600nm/mm, similar to those obtained by Shevkani et al.

The film cast both in the presence and absence of mTGase macroscopically appears quite tractable and flexible with a homogeneous structure. YM data show that films cast in the absence of mTGase are stiffer than those cast with mTGase, the latter having lower YM values. It has been demonstrated that suspension of grass pea flour treated or not with mTGase in the presence of a very low amount (8%) of glycerol, used as a plasticizer, is able to produce edible films.

Optical analyzes show that grass-pea flour-based films are quite transparent in the presence of mTGase, the film opacity being 7 times greater than that performed by the transparent CTA and 8 times lower than the opaque PP5. Finally, mechanical analyzes showed that the bioplastics prepared in the presence of mTGase were more resistant, more stretchable and less stiff than those prepared in the absence of the enzyme.

Figure 1. Zeta-potential of grass pea flour suspension as function of pH. Values in the frame represent the Zeta-potential range of stability.
Figure 1. Zeta-potential of grass pea flour suspension as function of pH. Values in the frame represent the Zeta-potential range of stability.

Hình ảnh

Figure 1. Cross-section SEM image of as sprayed YSZ top coats (Samples A, B, C, and D) deposited at a standoff distance of 70 mm, on BC with different surface treatments: (a) mirror polishing; (b) grinding;
Figure 2. Crack/column density (a), deposition efficiency (b), and porosity (c) for as-sprayed YSZ top coats (Samples A, B, C, and D) deposited on BC with different surface treatments.
Figure 3. Cross-section SEM images of as-sprayed YSZ top coats (Samples E–I) deposited at a standoff distance of 100 mm, on BC with different surface treatments: (a) mirror polishing; (b) grinding; (c) grit blasting; (d) as-sprayed; and (e) as-sprayed roug
Figure 8. Photographs of thermally-cycled samples: (a) Sample M, (c) Sample N, and (e) Sample O; and cross-section SEM images of thermally-cycled samples: (b) Sample M, (d) Sample N, and (f) Sample O.
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