Texturing Process Research Articles

Surface texturing of non-toxic, biocompatible titanium alloys via electro-discharge

The developments of Al and V free, biocompatible Ti-alloy have been the subject of researcher in the orthopedic joints replacement domain. The current article addresses the methodology chosen for Ti-alloy design, machinability, and low-cost surface texturing process for a high degree of biocompatibility. It is evident that an astonishing increase in biocompatibility can be achieved by synchronizing electro-discharge spark energy within Ti alloy and tool material coupled with the selection of dielectric medium for surface modification. The finding of this research may benefit a wide range of researchers to design sustainable implants. The positive polarity tool electrode at 10 A is the most desirable process parameter developing the bioactive surface.

Influence of Relative Displacement on Surface Roughness in Longitudinal Turning of X37CrMoV5-1 Steel.

The shaping process of surface texture is complicated and depends on many factors and phenomena accompanying them. This article presents the author’s test stand for the measurement of relative displacements in a tool–workpiece system during longitudinal turning. The aim of this study was to determine the influence of edge radius on the relative displacement between the tool and workpiece. The cutting process was carried out with inserts with different edge radii for X37CrMoV5-1 steel. As a result of the research, vibration charts of the tool–workpiece system were obtained. In the range of feed 0.03–0.18 mm/rev, the values of the standard deviation of relative displacements in the x-axis were obtained in the range of 0.36–0.78 μm for the insert with an edge radius of rn = 48.8 μm. As a result of the work, it was determined that for the feed value of 0.12 mm/rev for all inserts, the relative displacements are the smallest. As the final effect, the formula for forecasting the Ra roughness parameter was presented.

High speed laser induced periodic structure generation using femtosecond laser on surface of titanium

In this work femtosecond laser wavelength of 800nm, 1KHZ repetition rate and pulse length 100fs irradiation surface texturing has been used. The laser surface texturing is distinguished itself than other conventional processing due to its simplicity controllability and reproducible in creating various structures and wide range of applications. A labview compact zaber xy stage is used for this purpose and investgated the high scanning speed (20mm/s,10mm/s) surface structures on Titanium plate. The velocity of sample position used as function to generate modified surface structures. The surface textured studied by effect of variation of scanning velocity and this texturing process has been done in air medium by above selected parameters. FESEM sample characterization study of surface morphology has been done to details study of textured sample surface.

Visible-infrared spectroscopy of ungrouped and rare meteorites brings further constraints on meteorite-asteroid connections

The composition of asteroids gives crucial insights into the formation and evolution of the Solar System. Although spectral surveys and spacecraft missions provide information on small bodies, many important analyses can only be performed in terrestrial laboratories. Meteorites represent our main source of samples of extraterrestrial material. Determining the source asteroids of these meteorites is crucial to interpret their analyses in the broader context of the inner Solar System. For now, the total number of parent bodies represented in our meteorites collection is estimated to about 150 parent bodies, of which 50 parent bodies represented by the poorly studied ungrouped chondrites. Linking ungrouped meteorites to their parent bodies is thus crucial to significantly increase our knowledge of asteroids. To this end, the petrography of 25 ungrouped chondrites and rare meteorite groups was studied, allowing grouping into 6 petrographic groups based on texture, mineralogy, and aqueous and thermal parent body processing. Then, we acquired visible-near-infrared (VIS-NIR) reflectance spectroscopy data of those 25 meteorites, in order to compare them to ground-based telescopic observations of asteroids. The reflectance spectra of meteorites were obtained on powdered samples, as usually done for such studies, but also on raw samples and polished sections. With asteroids surfaces being more complex than fine-grained regolith (e.g., asteroid (101955) Bennu), in particular near-Earth asteroids, the use of raw samples is a necessary addition for investigating parent bodies. Our results showed that sample preparation influences the shape of the spectra, and thus asteroid spectral matching, especially for carbonaceous chondrites. Overall, the petrographic groups defined initially coincide with reflectance spectral groups, with only few exceptions. The meteorite spectra were then compared with reference end-member spectra of asteroids taxonomy. We matched the 25 studied meteorites to asteroids types, using a qualitative match of the shape of the spectra, as well as a quantitative comparison of spectral parameters (bands positions, bands depths and slopes at 1 and 2 μm). We define links between some of the studied ungrouped chondrites and asteroid types that had no meteorite connection proposed before, such as some very primitive type 3.00 ungrouped chondrites to B-type or Cg-type asteroids. We also matched metamorphosed ungrouped carbonaceous chondrites to S-complex asteroids, suggesting that this complex is not only composed of ordinary chondrites or primitive achondrites, as previously established, but may also host carbonaceous chondrites. Conversely, some ungrouped chondrites could not be matched to any known asteroid type, showing that those are potential samples from yet unidentified asteroid types.

Rotational stability of modified toric intraocular lens.

We evaluated the rotational stability of a new toric intraocular lens (IOL), HOYA XY-1 toric IOL that is an improved version of HOYA 355 toric IOL, with longer overall length (13.0 mm vs. 12.5 mm), shortened unfolding time, and texture processing of the surface of haptics. Data from 193 eyes of 165 patients (76.4 ± 8.3 years old) with preoperative corneal astigmatism exceeding 0.75 diopters who had undergone phacoemulsification and toric IOL implantation were collected and analyzed. Corneal astigmatism, refractive astigmatism, and uncorrected (UDVA) and corrected distance visual acuity (CDVA) were evaluated before and 1 day, 1 week, and 1 month after surgery. The degree of IOL decentration, IOL tilt, and toric axis misalignment was assessed at 1 day and 1 month postoperatively. Fifty eyes received AcrySof toric IOL, 51 eyes TECNIS toric IOL, 46 eyes HOYA 355 toric IOL, and 46 eyes HOYA XY-1 toric IOL. The amount of axis misalignment from the intended axis was significantly different among IOLs (p = 0.004, one-way ANOVA), and HOYA XY-1 showed significantly less amount of axis misalignment than TECNIS (p = 0.020, Tukey’s multiple comparison) and HOYA 355 (p = 0.010). The proportion of eyes that showed axis misalignment <10° at 1 month postoperatively was significantly higher with HOYA XY-1 toric IOL than with other toric IOLs (χ2 test, p = 0.020). HOYA XY-1 toric IOL, the modified version of HOYA 355 toric IOL, showed excellent rotational stability in comparison with other models of toric IOLs.

Reducing engine oil and fuel consumptions by multidimensional laser surface texturing on cylinder surface

• Proposed the multidimensional laser surface texturing (MLST) process, based on the engine motion characteristic. • Established hardware and software systems and optimized the parameters of MLST process. • The ablating position of each laser pulse is manipulated, and various depths of micro dimples are fabricated by controlling the repeat times of overlapped laser pulses. • Developed the post-process for MLST process, based on the finishing honing process to remove the recast bulges (RCB) induced by laser ablation. • Tested four schemes of cylinder liners (one prototype, three MLST) on a single cylinder diesel engine at rated power and speed. • One of MLST scheme reduced engine oil and fuel consumptions simultaneously. The optimization of cylinder surface topography draws immense amounts of researches, since it has far-reaching effects on engines’ overall performances. In order to promote the lubricity of ring/bore interface, the present study developed the multidimensional laser surface texturing (MLST) process, which fabricates controllable arrays of micro dimples on cylinder surface. The MLST process was achieved by a series of innovations, including its hardware and software systems, and optimization of process parameters and efficiency. A post-process was developed based on the finishing honing process to remove the recast bulges (RCB) induced by laser ablation. Additionally, the cylinder liners with different surface texturing schemes were bench tested on a single cylinder diesel engine. The experimental results indicated that near TDC (top dead center) region and piston skirt contacting region (SKIRT) were two high-impact regions for the technical efficiency of the MLST process. Benefiting from the reasonable optimization of oil distribution and enhanced hydrodynamic lubrication, the MLST process was able to reduce engine oil and fuel consumptions simultaneously. This paper provides a comprehensive introduction of equipment, pre- and post-process, and capacities of the newly developed surface modification technology.

Formation of ideally ordered porous anodic zirconia by anodization of vacuum deposited Zr on molds

We studied the formation of ideally ordered nanoporous zirconia by anodizing Zr having a texturing pattern. A texturing pattern was formed on a Zr surface by peeling off a sputtered zirconium film from a metal (Ni) mold having an ordered array of convexes. In contrast to texturing by nanoimprinting, the present texturing process never requires the pressing of a mold onto the Zr surface. During the anodization of Zr that has a texturing pattern on its surface, which is an ideally ordered array of concaves, each concave acted as a starting point of the formation of nanoholes. By the present process, porous anodic zirconia having an ideally ordered array of nanoholes was obtained. The interval between nanoholes in the porous anodic zirconia agreed with the texturing pattern.

A resource saving technology for industrial processing of deep-sea and demersal fishes

This article shows the results of testing the technology of producing combined fish farce from deep-sea and demersal fishes. The object of our research is frozen fish, such as Giant grenadier (Albatrossia pectoralis), Alaska plaice (Pleuronectes quadritubercula-tus), Pacific halibut (Hippoglossus stenolepis) and Pacific ocean perch (Sebastes alutus). We found out that a combination of Giant grenadier (Albatrossia pectoralis) and demersal fishes, such as Alaska plaice (Pleuronectes quadrituberculatus), Pacific halibut (Hippoglossus stenolepis) and Pacific ocean perch (Sebastes alutus) in the proportion of 50:50 and a certain salt curing method make it possible to produce high-quality farce systems. We provide a scientific basis for the certain technological parameters defining the formation process of farce system texture depending on the quantity of sodium chloride, temperature of salt curing and length of curing. We found out that sodium chloride at a rate of 1.5-2.0% increases rheological properties of combined fish farce. We outlined conditions and parameters of technological treatment affecting the quality characteristics of ground fish muscle of giant grenadier (Albatrossia pectoralis) with preliminary salt curing. We found out that the highest values of adhesiveness, viscosity, water retention capacity and yield strength belong to experimental samples with 1.5-2.0% of sodium chloride to the raw mass with the temperature of curing plus 20±2°C and reasonable curing time of about 15-20 minutes. Based on the data obtained, it seems promising to produce combined fish farce from deep-sea and demersal fishes, since this method makes it possible to improve their functional and technological properties and to increase consumption of deep-sea and demersal fishes for food.

Influence of surface structure on the performance of mono-like Si PERC solar cell

Mono-like Si wafers were textured by both alkaline solution and metal-assisted chemical etching (MACE) process. The influences of surface textures on the diffusion process, surface passivation, electrical property and performance of solar cells were investigated. The results show that the pyramid-like structures obtained by alkaline texturing facilitates a higher surface doping concentration, larger junction depth after diffusion and better passivation effect, compared with the honeycomb-like structures generated by MACE texturing. In the same wafer textured by alkaline solution or MACE, the mono-crystalline region exhibits a higher quantum efficiency than the multi-crystalline region. By combining the MACE and alkaline texturing processes, the honeycomb- and pyramid-like structures were generated on the surface of mono-like Si wafer, resulting in a conversion efficiency of 21.39% that is higher than that of the individually MACE or alkaline-textured solar cells by 0.4% and 0.02%, respectively.

Investigation on Electrically-Assisted Rolling Process of Surface Texture for Drag Reduction

Surface texture is employed for drag reduction in the aviation and aerospace, since it has a positive effect on boundary layers of flow. In this paper, the triangular surface texture was formed via the rolling process. The effects of the roll gap, sheet thickness, the space and size of the triangular shape on the forming quality of the surface texture were studied. The simulation indicates that a small roll gap is benefit for forming full profile. With the decrease of sheet thickness, the forming height is greater, but the sheet flatness is poorer. The size and space of riblet have significant effects on the stress and strain distribution and forming height. When the electric current is introduced into the rolling process, the formed surface texture shows greater forming profile and better flatness. It is concluded that the electrically-assisted rolling process is a promising way of forming surface texture on metal sheets.

Laser Surface Texturing Process and Its Mechanism for Brass Material

Laser Surface Texturing Process and Its Mechanism for Brass Material

Factors affecting morphological and electrical properties of Barium Titanate: A brief review

Abstract Lead Zirconate Titanate has been extensively used to make ultrasound transducers, sensors, and actuators as well as high-value ceramic capacitors for a very long time. The main disadvantage of Lead Zirconate Titanate is its toxic nature due to the presence of Lead, which has been banned in most of the nations around the globe. In search of Lead-free materials as a suitable replacement to Lead Zirconate Titanate, Barium Titanate is a very strong candidate. It can be used as an electrical insulator in its purest form. Doped Barium Titanate is a promising tunable material with enhanced ferroelectric and piezoelectric properties which can be a good alternative to Lead Zirconate Titanate. Properties of Barium Titanate are found to change with preparation routes, doping, and other factors. Variation in dielectric constant and high permittivity makes Barium Titanate a useful material for many applications in modern electronic devices. In this paper, analysis has been done on the changes that occur in the properties of Barium Titanate with different factors like crystallographic orientation, grain size, texturing, doping concentration, and sintering process. The piezoelectric property makes Barium Titanate useful for many applications like semiconductors, positive temperature-coefficient resistors, transducers, and ceramics. From the perspective of future applications, materials possessing good fracture toughness improved piezoelectric and dielectric properties, and higher temperature stability is needed. Therefore, it is concluded that the properties of Barium Titanate are enhanced when doped with suitable materials like Mn, Ce, Ti, Fe, Zr, etc. and by adopting different preparation routes like the sol–gel method, hydrothermal method, chemical alloying method, co-precipitation method, and polymeric precursor method.

Optimization of air jet texturing parameters for acrylic filament yarns

A statistical work was performed to investigate effect of air jet texturing process parameters on acrylic filament yarn properties. It was shown that process parameters such as air pressure, overfeed and texturing speed significantly affect resultant yarn properties. Some structural changes were also observed by varying process parameters. Contrary to reported information in the literature, tenacity of air textured acrylic yarn increased by the increment of air pressure and it was found to be relevant with instability of the yarn. Overfeed and texturing speed had also significant effect as increase of both parameters resulted in lower yarn tenacity. Structural changes have also been observed especially with the change of air pressure and it was found that increase of air pressure up to some extent disturbed crystalline orientation of the yarn. According to statistical analysis and characterization methods, optimum parameters were determined as 300 m/min texturing speed, 5 bar air pressure and 5% overfeed for acrylic yarn used in this study.

78 The effects of guar gum and other select gums and gelling carbohydrates on appearance, texture, and heating characteristics of wet pet foods

Abstract Many wet pet foods include carbohydrate ingredients that enhance viscosity for container filling or provide structure after processing. These gums and gels can cause differences in commercial sterilization as well as visible changes in product quality. Therefore, the objective was to determine the effect of different gums and gelling carbohydrates on the appearance, texture, and thermal processing metrics of wet pet foods. Treatments were added to a chicken-based formula as 1% dextrose (NH), 0.5% guar gum and 0.5% dextrose (GG), 0.5% guar gum and 0.5% kappa carrageenan (KCGG), 0.5% guar gum and 0.5% locust bean gum (LBGGG), or 0.5% guar gum and 0.5% xanthan gum (XGGG). Batters were analyzed for pH, water activity, and consistency with a Bostwick consistometer as a crude indication of viscosity. Thermocouples were placed in cans to measure cold-spot temperatures for Fo and cook-value calculations. Replicate batches (n = 3) included each treatment and were commercially sterilized in a still retort at 121 ℃ and 144.79 kPa. Can vacuum and product color (colorimetry) were measured after cans cooled to ambient temperatures. Treatments were analyzed as a 1-way ANOVA with batch as a blocking factor. Means were separated by Fisher’s LSD using statistical analysis software (GLIMMIX; SAS 9.4). Batter consistency thickened (P &amp;lt; 0.05) with increasing levels of gums and gelling carbohydrates. Batter pH, batter water activity, and can vacuum were not different (P &amp;gt; 0.05) among treatments (averaging 5.94, 0.990, and -12.9 kPa, respectively). The NH treatment accumulated the greatest (P &amp;lt; 0.05) Fo and cook values during the cook cycle compared to all other treatments. The NH and GG treatments were more (P &amp;lt; 0.05) red and yellow than KCGG, LBGGG, and XGGG. Gums and gelling carbohydrates influenced the rate of heat penetration of the foods, likely due to the differences in batter consistency, and affected product color and physical characteristics.

Neural sensitivity to natural image statistics changes during middle childhood.

Natural images have properties that adults' behavioral and neural responses are sensitive to, but the development of this sensitivity is not clear. Behaviorally, children acquire adult-like sensitivity to natural image statistics during middle childhood (Ellemberg et al., 2012), but infants exhibit sensitivity to deviations of natural image structure (Balas & Woods, 2014). We used event-related potentials (ERPs) to examine sensitivity to natural image statistics during childhood at distinct processing stages (the P1 and N1 components). We presented children (5-10years old) and adults with natural images varying in positive/negative contrast, and natural/synthetic texture appearance to compare electrophysiological responses to images that did or did not violate natural statistics. We hypothesized that children would acquire sensitivity to these deviations late in middle childhood. Instead, we observed significant responses to unnatural contrast and texture statistics at the N1 in all age groups. At the P1, however, only young children exhibited sensitivity to contrast polarity. The latter effect suggests greater sensitivity earlier in development to some violations of natural image statistics. We discuss these results in terms of changing patterns of invariant texture processing during middle childhood and ongoing refinement of the representations supporting natural image perception.

Rotating edge-field driven processing of chiral spin textures in racetrack devices

Topologically distinct magnetic structures like skyrmions, domain walls, and the uniformly magnetized state have multiple applications in logic devices, sensors, and as bits of information. One of the most promising concepts for applying these bits is the racetrack architecture controlled by electric currents or magnetic driving fields. In state-of-the-art racetracks, these fields or currents are applied to the whole circuit. Here, we employ micromagnetic and atomistic simulations to establish a concept for racetrack memories free of global driving forces. Surprisingly, we realize that mixed sequences of topologically distinct objects can be created and propagated over far distances exclusively by local rotation of magnetization at the sample boundaries. We reveal the dependence between chirality of the rotation and the direction of propagation and define the phase space where the proposed procedure can be realized. The advantages of this approach are the exclusion of high current and field densities as well as its compatibility with an energy-efficient three-dimensional design.

Effective Surface Texturing of Diamond-Wire-Sawn Multicrystalline Silicon Wafers Via Crystallization of the Native Surface Amorphous Layer

To increase the market shares of multicrystalline silicon (mc-Si) wafers obtained using diamond-wire sawing (DWS), it is necessary to develop efficient and cost-effective texturing methods. Surface texturing processes that increase light absorption are essential for manufacturing high-efficiency solar cells. The smooth surface, phase transformations, and amorphous silicon (a-Si) layer on mc-Si wafers manufactured via DWS hinder the effective texturing under conventional acidic conditions, which are typically used for multiwire slurry sawing (MWSS). To address this issue, this article focused on an efficient texturing process of DWS wafers by adapting a pre-thermal treatment (TT) process. We found that DWS mc-Si wafers could be effectively textured after the TT process by altering the surface roughness through the crystallization of surface amorphous silicon (a-Si) and phase transformation layers. For the DWS mc-Si wafers textured under conventional acidic etching conditions without TT, Rw was found to be 31.7%. The altered surface conditions achieved via the proposed TT method facilitate effective texturing on the DWS mc-Si wafer surface. Consequently, a weighted average reflectance (Rw) of 24.5% was obtained, which was comparable to that for MWSS mc-Si wafers subjected to conventional acidic etching (Rw = 24.4%). As a result of depositing a SiN x for surface passivation and antireflection coating in solar cell applications, Rw values of 8.1% and 8.3% were obtained for the thermal treated DWS mc-Si wafer and MWSS mc-Si wafer, respectively. The proposed texturing process for DWS mc-Si wafers can easily be applied to industrial inline processes using cost-effective existing acidic etching solutions.

Hierarchically ordered microcrater array with plasmonic nanoparticle clusters for highly sensitive surface-enhanced Raman scattering

Surface-enhanced Raman scattering (SERS) with unique molecular vibrational fingerprints for identifying analytes provides an effective spectroscopic approach for the detection of trace molecules in biomedical/analytical fields. Although a great amount of efforts has been devoted to developing various SERS substrates with hierarchical micro/nanostructures, challenges remain in completely concentrating the target molecules within a sensitive area and thereby enhancing detection sensitivity. Here, we report trace molecular detection using superhydrophobic microcrater array as surface-enhanced Raman substrate (SMA-SERS). The hierarchically ordered microcrater array with plasmonic nanoparticle clusters is quickly obtained by the two-step process of femtosecond laser texturing and magnetron sputtering. The resultant substrates with hierarchical micro-/nanostructures show excellent superhydrophobicity with a contact angle above 150° and satisfactory plasmonic nanostructures with the easily attainable Raman signal enhancement factor of ~4.82 × 108. The signals on the SMA-SERS maintain uniformity with a relative standard deviation of <15%. These findings manifest that the SMA-SERS is an extraordinary strong candidate for obtaining high-quality and reliable SERS, facilitating a widespread use of SERS for practical applications.

On the Formation of Black Silicon Features by Plasma-Less Etching of Silicon in Molecular Fluorine Gas.

In this paper, we study the plasma-less etching of crystalline silicon (c-Si) by F2/N2 gas mixture at moderately elevated temperatures. The etching is performed in an inline etching tool, which is specifically developed to lower costs for products needing a high volume manufacturing etching platform such as silicon photovoltaics. Specifically, the current study focuses on developing an effective front-side texturing process on Si(100) wafers. Statistical variation of the tool parameters is performed to achieve high etching rates and low surface reflection of the textured silicon surface. It is observed that the rate and anisotropy of the etching process are strongly defined by the interaction effects between process parameters such as substrate temperature, F2 concentration, and process duration. The etching forms features of sub-micron dimensions on c-Si surface. By maintaining the anisotropic nature of etching, weighted surface reflection (Rw) as low as Rw < 2% in Si(100) is achievable. The lowering of Rw is mainly due to the formation of deep, density grade nanostructures, so-called black silicon, with lateral dimensions that are smaller to the major wavelength ranges of interest in silicon photovoltaics.

Improving fluid retention properties of 316L stainless steel using nanosecond pulsed laser surface texturing

Stainless steel has been used as a successful biomaterial for decades. In this study, a pulsed nanosecond laser was used to create patterned surfaces of stainless steel coupons to study the effect of patterning on fluid retention and biocompatibility studies of laser patterned and control surfaces. An AVIA 355 nanosecond pulsed laser was used with different laser parameters to create unique “peak and valley” structures (uniform textured surface) on stainless steel coupons of size of 1 × 1 × 0.1 cm3. The surface structural changes can be attributed to the Gaussian beam profile of the laser. The coupons were observed under a scanning electron microscope to understand the change of the material surface profile. An optical profilometer was used to measure the surface roughness and compare it with a nontextured or control surface. The contact angle measurement showed a decrease in the contact angle, reduced to 71.6° from 82.2° making the patterned surface more hydrophilic. A biocompatibility study of the stainless steel was performed to evaluate the effect of surface modification on its impact on biocompatibility. The cell viability of the patterned sample was 94% as compared to 84% for the unpatterned surface. A simulation of the process was run using flow3d® to understand the behavior of the material during the texturing process. The results obtained from the simulation process were compared with the experimental data and found to be in good agreement. The effects of Gaussian beam, vapor pressure, and overlapping of the beam were also analyzed in the simulation process.