Surface Appearance Research Articles

Explaining the Anomaly Detection in Additive Manufacturing via Boosting Models and Frequency Analysis

Anomaly detection is an important feature in modern additive manufacturing (AM) systems to ensure quality of the produced components. Although this topic is well discussed in the literature, current methods rely on black-box approaches, limiting our understanding of why anomalies occur, making complex the root cause identification and the consequent decision support about the action to take to mitigate them. This work addresses these limitations by proposing a structured workflow designed to enhance the explainability of anomaly detection models. Using the wire arc additive manufacturing (WAAM) process as a case study, we examined 14 wall structures printed with INVAR36 alloy under varying process parameters, producing both defect-free and defective parts. These parts were classified based on surface appearance and welding camera images. We collected welding current and voltage data at a 5 kHz sampling rate and extracted features from both time and frequency domains using a knowledge-based approach. Isolation Forest, k-Nearest Neighbor, Artificial Neural Network, XGBoost, and LGBM models were trained on these features, and the results shown best performance of boosting models, achieving F1 scores of 0.927 and 0.945, respectively. These models presented higher performance compared to other models like k-Nearest Neighbor, whereas Isolation Forest and Artificial Neural Network posses lower performance due to overfitting, with an F1 score of 0.507 and 0.56, respectively. Then, by leveraging the feature importance capabilities of these models, we identified key signal characteristics that distinguish between normal and anomalous behavior, improving the explainability of the detection process and in general about the process physics.

Identifying failure factors due to corrosion erosion on pressured steam pipe elbow in geothermal power plant

This paper presents the findings of a corrosion erosion failure analysis of elbow pipe materials used to flow high-pressure water from underground. The failed elbow pipe material was above the wellhead forming a straight line in the longitudinal direction with a pipe length of 6200 feet below the ground surface. The working fluid in the elbow pipe was 25 % steam and 75 % water, flowing in the elbow pipe with a media flow rate of 180 tons per hour, a pressure of 22 bar, and a temperature of 220 °C. Elbow tubes were made of low carbon steel with Standard ASTM A234 having an outer diameter of 304.8 mm and a wall thickness of 9.271 mm. Macroscopic testing, chemical composition analysis, metallographic testing, hardness testing, X-ray diffraction testing, SEM, and EDS are a few of the test types conducted. The study's findings showed that the elbow tubes experienced a thinning process on the inner wall of the outer curvature side with a rough and wavy surface texture or appearance. This type of failure is known as erosion-corrosion. The level of erosion-corrosion failure that occurs is greatly influenced by the pH of the fluid being flowed reaching 2.67–2.91, this is due to the very high Cl- of 1290 ppm, so the higher the rate of erosion-corrosion that occurs. These materials are the most popular and widely used in the oil and gas sector. However, this pipe has weaknesses because it is susceptible to erosion-corrosion Therefore, it is very important to choose the right material, namely, a material that is resistant to erosion-corrosion

Bio-inhibitive corrosion effect of carica papaya leaf extract on cold-rolled mild steel in 0.1 M HCl solution

Plant extracts are prone to microbial growth that can lead to microbial-induced corrosion (MIC), a major setback for their performance and stability as corrosion inhibitors. Hence, this work aims to identify the microbes that may cause the ineffectiveness of carica papaya leaf extract (CPLE) as a bio-corrosion inhibitor of cold-rolled mild steel in 0.1 M HCl solution for 48 days at 28℃. Cold-rolled mild steel coupons were immersed in 100 ml of 0.1 M hydrochloric (HCl) acid solution containing 1 g, 2 g, 3 g, 4 g, and 5 g of carica papaya leaf extract (CPLE) for 48 days at 28℃. The gravimetric method was used to determine the coupons' corrosion rate (CR), surface coverage, and inhibition efficiency (IE%) of the CPLE. The functional groups in the CPLE were identified using Fourier Transform Infrared Spectroscopy (FTIR), and the surface appearance of the coupons after immersion was examined using an atomic force microscope (AFM). Gravimetric data showed the coupons dipped in a 0.1 M HCl solution containing 3 g/100 ml of the inhibitor exhibited the highest inhibition efficiency of 87.73%, surface coverage of 0.88, and lowest corrosion rate of 0.00255 mm/day or 0.93 mm/yr, after 48 days at 28℃. In FTIR, transmittance peaks occurred at 1558 cm−1 for amines (-NH) in alkaloid scissoring, 1452 cm−1 for aromatic -C = C in flavonoids, 2932 cm−1 for aliphatic methylene (-CH2) and aldehyde (RCOH) stretching, 1035 and 1077 cm−1 for aromatic-OR in tannin, and 3280 cm−1 for out-of-plane bending of hydroxyl (-OH) in phenolics. Vitamin C (522,940 μg/g), flavonoids (860 μg/g), saponins (637.9 μg/g), terpenoid (48.4 μg/g), phenol (120%μg/g), alkaloid (4.18 μg/g), tannin (59.84%), and glycosides (9.04%) make up the extract's average phytochemical content. AFM presents pits and ridges on the mild steel coupons immersed in 0.1 M HCl solution without the extract. Those immersed in the solutions with varying concentrations of the extract had a passive layer of the CPLE adhering to the surfaces of the coupons thereby preventing the coupon’s direct contact with the acid solution and weight loss. However, over time, microbial growth decreased the efficiency of CPLE due to metabolites. Microbial tests show creamy, irregular and raised bacterial total colony-forming units per gram (Tcfu/g) as 4.6 × 105 Tcfu/g and 1.9 × 107 Tcfu/g in 2 runs. Also, a mixture of white and fluffy appearance and spore formation of fungi population of 4.8 × 105 Tcfu/g and 3.2 × 107 Tcfu/g in 2 Runs made up of Penicillium spp, Coccidioides immitis, Aspergillus flavus, and Fusarium spp, with hyphae, were seen in the solutions containing CPLE.

Fe(OH)3/Ti3C2Tx nanocomposites for enhanced ammonia gas sensor at room temperature

Two-dimensional material (2D material) MXene has great application potential in gas sensors because of its excellent controllable performance and vast specific surface area. In this study, we used a straightforward in-situ electrostatic self-assembly technique to create Fe(OH)3/Ti3C2Tx nanocomposites, which were then used to fabricate gas sensors for ammonia detection at room temperature (25 ℃). Several characterization methods were performed aimed at determining the surface appearance and construction of the nanocomposites, and the sensing characteristics and mechanism were also systematically examined. The findings demonstrate the effective incorporation of amorphous Fe(OH)3 nanoparticles on the surface of Ti3C2Tx. Additionally the nanocomposites of Fe(OH)3/Ti3C2Tx have considerably higher specific surface area than pure Ti3C2Tx, hence offering more active NH3 adsorption sites. The response of the sensor to 100 ppm NH3 was 48.6% at room temperature, which was 9.3 times more higher than that of pure Ti3C2Tx. The sensors also have the advantages of long-term stability (33 days), low NH3 detection limit (500 ppb), and rapid recovery time (85 s) and response times (78 s). It is anticipated that this work will be helpful for developing the new generation of wearable ammonia sensors at room temperature.

Synergetic effect of bioglass and nano montmorillonite on 3D printed nanocomposite of polycaprolactone/gelatin in the fabrication of bone scaffolds

Nowadays, bone injuries and disorders have increased all over the world and can reduce the quality of human life. Bone tissue engineering repair approaches require new biomaterials and methods to construct scaffolds with the required structural properties as well as improved performance. As potential therapeutic strategies in bone tissue engineering, 3D printed scaffolds have been developed. Polycaprolactone/Ceramic composites have attracted considerable attention due to their cytocompatibility, biodegradability, and physical properties. In this study, a 3D printing process was used to create polycaprolactone (PCL)-Gelatin (GEL) scaffolds containing varying concentrations of Bioglass (BG) and Nano Montmorillonite (MMT). This mixture was then loaded into a 3D printer, and the scaffolds were printed layer by layer. After constructing the scaffolds, they were then examined for their physical, chemical, and biological characteristics. Surface appearance was analyzed with a scanning electron microscope (SEM), which revealed that NC increased the diameter of pores from 465 to 480 μm. The elements in the scaffolds were evaluated by EDX analysis, and a uniform dispersion of nano montmorillonite particles was observed. The compressive strength reached 76.43 MPa for PCL/G/35 %MMT/15 %BG scaffold. Also, the rate of water absorption, biodegradability and bioactivity of PCL-GEL scaffolds increased significantly in the presence of NC. According to the MTT cell test results, adding BG and NC increased cell proliferation, adhesion and cell viability to 127.7 %. These findings indicated that the 3D printed PCL/G/35 %MMT/15 %BG scaffold has promising strategies for bone repair applications. Also, polynomial curve fitting shows that scaffold degradability after soaking in PBS can be predicted using the initial weight and soaking time. Adding more variables and data could improve prediction accuracy, reducing the need for experiments and conserving resources.

Design of Two-Layer Roller Compacted Concrete with Joints by KENSLAB

Roller compacted concrete (RCC) is a type of rigid pavement that is designed in a similar way to conventional concrete pavements reflecting its mode of failure. The thickness design of RCC pavements is based on keeping the flexural stresses and fatigue damage in the pavement caused by wheel loads within allowable limits. As in all jointed concrete pavements, there is a greater effect from loads placed along edges and less at interior locations in the pavement. Joints in RCC pavement are clearly critical areas and form weak points. RCC is typically constructed with saw-cut joints to prevent random cracking, improve the appearance of the pavement surface, and maintain the highest possible load transfer across the joints. This paper presents an approach to designing the thickness of a two-layer RCC with induced cracks (i.e., joints) based on load transfer stiffness and fatigue damage, using the KENSLAB program to obtain pavement life, predict joint deterioration, and pavement damage.

A NEW PERSPECTIVE ON CHINESE RED GLAZE

Glazes obtained by the reduction method, also called Chinese red or copper red in the literature, were first seen on porcelains of the Tang Dynasty (618-907) and Northern Song Dynasty (960-1126) periods in China. These glazes, which require a very difficult process to produce, are obtained by reducing the copper compounds in the recipe in the kiln. From its historical process to the present day, the surface of Chinese red glazes has been desired to be shiny and smooth, and their production has been carried out according to this principle. Within the scope of this study, a new artistic perspective was wanted to be brought to Chinese red glazes and instead of a smooth surface appearance, a pin hole image, known as a glaze defect, was desired. For this purpose, silicon carbide (SiC) was used to achieve the desired effect. Under normal conditions, the reduction process is carried out when the kiln cools down after neutral firing. However, a different perspective was tried to be provided by developing an alternative firing method to the traditional Chinese red glazes obtained by reduction. In order to contribute to the language of discourse in art ceramics, a new proposal is presented with the interpretation of Chinese red glazes.

Development and in vitro Evaluation of Nanoemulsion-based Polyherbal Hair Serum Formulations for Leave-in Hair Treatments

Background: Hair is a prominent physical feature that is found in all mammals. Different hair types will display different hair physicochemical properties (colour and appearance), mechanical resistance and reactivity to chemical agents and surface properties. Objectives: This study aims to prepare polyherbal-based hair serum to conduct stability tests and in-vitro evaluation tests to assess the efficacy of hair serum on different types of human hair tresses for the purpose of leave-in hair treatments Methods and Material: The hair care formulations, such as hair serum, were prepared and their stability was evaluated through a series of tests. The stability tests were conducted by evaluating the organoleptic properties of the formulations, such as colour, odour, surface appearance, consistency, and clarity, under various environmental conditions over a period of four weeks. Results: The relative viscosity of the hair serum is 7.84mPa/s, relative density is 0.997g/ml, and an average particle size is 1079 ± 21.22 μm. Over the course of 4 weeks, the nanoemulsion-based hair serum was stable between 25 – 40 °C and away from direct sunlight exposure. Conclusion: The formulated polyherbal hair serum can be used as a leave-in treatment to maintain hair’s moisture balance while improving hair combability. Further improvements in the hair product formulation can be made in the future to increase their potential for commercialisation

Anatomy of a fumarole field: drone remote-sensing and petrological approaches reveal the degassing and alteration structure at La Fossa cone, Vulcano, Italy

Abstract. Hydrothermal alteration and mineralization processes can affect the physical and chemical properties of volcanic rocks. Aggressive acidic degassing and fluid flow often also lead to changes in the appearance of a rock, such as changes in surface coloration or intense bleaching. Although hydrothermal alteration can have far-reaching consequences for rock stability and permeability, limited knowledge exists on the detailed structures, extent, and dynamic changes that take place near the surface of hydrothermal venting systems. By integrating drone-based photogrammetry with mineralogical and chemical analyses of rock samples and surface gas flux, we investigate the structure of the evolving volcanic degassing and alteration system at the La Fossa cone on the island of Vulcano, Italy. Our image analysis combines principal component analysis (PCA) with image classification and thermal analysis through which we identify an area of approximately 70 000 m2 that outlines the maximum extent of hydrothermal alteration effects at the surface, represented by a shift in rock color from reddish to gray. Within this area, we identify distinct gradients of surface coloration and temperature that indicate a local variability in the degassing and alteration intensity and define several structural units within the fumarole field. At least seven such larger units of increased activity could be constrained. Through mineralogical and geochemical analysis of samples from the different alteration units, we define a relationship between surface appearance in drone imagery and the mineralogical and chemical composition. Gradients in surface color from reddish to gray correlate with a reduction in Fe2O3 from up to 3.2 % in the unaltered regime to 0.3 % in the altered regime, and the latter coincides with the area of increased diffuse acid gas flux. As the pixel brightness increases towards higher alteration gradients, we note a loss of the initial (igneous) mineral fraction and a change in the bulk chemical composition with a concomitant increase in sulfur content from close to 0 % in the unaltered samples to up to 60 % in samples from the altered domains. Using this approach of combined remote-sensing and in situ analyses, we define and spatially constrain several alteration units and compare them to the present-day thermally active surface and degassing pattern over the main crater area. The combined results permit us to present a detailed anatomy of the La Fossa fumarole field, including high-temperature fumaroles and seven larger units of increased alteration intensity, surface temperature, and variably intense surface degassing. Importantly, we also identify apparently sealed surface domains that prevent degassing, likely as a consequence of mineral precipitation from degassing and alteration processes. By assessing the thermal energy release of the identified spatial units quantitatively, we show that thermal radiation of high-temperature fumaroles accounts for < 50 % of the total thermal energy release only and that the larger part is emitted by diffuse degassing units. The integrated use of methods presented here has proven to be a useful combination for a detailed characterization of alteration and activity patterns of volcanic degassing sites and has the potential for application in alteration research and for the monitoring of volcanic degassing systems.

Corrosion Resistance and In Vitro Biological Properties of TiO2 on MAO-Coated AZ31 Magnesium Alloy via ALD

The surface corrosion of magnesium alloys is effectively addressed currently by the creation of a micro-arc oxidation (MAO) ceramic layer. However, oxide film porousness restricts magnesium alloy use. Thus, this work used atomic layer deposition (ALD) to create a TiO2 coating on MAO-coated AZ31B magnesium alloy to plug micropores and increase corrosion resistance and biological characteristics. The samples were analyzed using SEM, EDS, XPS, and XRD to determine their surface appearance, chemical content, and microstructure. Micro-arc oxidation produced a 20 μm oxide coating. The TiO2 film reached 47.41 nm after 400 atomic layer deposition cycles. All corroded samples were tested for corrosion resistance using electrochemical and hydrogen evolution methods and examined for surface morphology. In vitro cell experiments examined biocompatibility. The results indicate that the TiO2 layer sealed the MAO coating’s micro-pores and micro-cracks, enhanced corrosion resistance, and preserved surface morphology following corrosion. The TiO2/MAO composite coating is more biocompatible than the substrate and MAO coating. This research proposes coating AZ31B magnesium alloy for bio-remediation to increase corrosion resistance and biocompatibility.

Unveiling Beauty: Belinda's Quest for Youth in Alexander Pope's "The Rape of the Lock"

Alexander Pope's mock-epic The Rape of the Lock illuminates the complexity of youth, beauty, and society in early 18th-century England. This paper examines Pope's sympathetic portrayal of Belinda, who represents society's idealised youthful beauty and its anxieties about its loss, to demonstrate his poetic aim to critically analyse and understand the dangers of attachment to surface appearances resulting from society's obsession with youth and beauty.

Assessment of chocolate retail in Ghana and willingness to use cooling devices

Cold temperature (≤20 ᵒC) storage or handling is required to maintain the quality characteristics of chocolate after production throughout the supply chain. The objective of this study was to assess the retail conditions, challenges, and willingness of retailers to use cooling devices. A total of 228 chocolate retailers sampled from Kumasi and Accra were interviewed using questionnaires with both closed and open-ended questions. The purposive, snowballing, and random sampling techniques were used. The collected data were analyzed using SPSS version 26. The majority of the respondents were female (82 %), aged between 21 and 30 years (33.9 %) and had a maximum of Junior High School education (39.0 %). About 15.4 % were registered retailers of Cocoa Processing Company - Ghana, 56.1 % sold on the streets of which 71.1 % sold under no shade and 71.9 % sold all day. A proportion of 76.2 % reported having challenges in their chocolate retail business. Among these challenges softening dominated with about 78.1 % of the retailers reported experiencing it in their daily operations. Spoilage (18.9 %), damage during handling (35.1 %), oily surface (34.2 %), darker surface appearance (10.1 %), and whitish surface appearance (39.9 %) were other challenges faced by retailers. The majority (76.8 %) of the respondents affirmed elevated temperatures caused melting, oil leakage and fat bloom in chocolate leading to rejections by clients. A significant proportion (81.1 %) indicated a cooling device for retail is necessary and were willing to use it when made available. The findings show that vending conditions were generally unsuitable for the shelf-stability of chocolates. An innovative vending device with cooling system would serve as possible intervention to mitigate the challenges faced by chocolate retailers.

High-strength, impact-resistant PP/PTFE composite foam with enhanced surface appearance achieved through mold-opening microcellular injection molding

Poor surface appearance and decreased mechanical performance are critical factors limiting the broad application of Microcellular injection molding (MIM) in foamed polymer products. Herein, in-situ polytetrafluoroethylene (PTFE) nanofibrils reinforced polypropylene (PP) foams with high strength, impact resistance, and enhanced surface quality were prepared by mold opening microcellular injection molding (MOMIM). PTFE nanofibers with different diameters were introduced into the PP matrix via twin screw extrusion and significantly enhanced the crystallinity and viscoelasticity of the PP matrix with the enhancement being more pronounced for the finer PTFE fibers. High-density oriented cellular structures were formed in the MOMIM PP/PTFE foams owing to the heterogeneous nucleation of PTFE and the stretching effect of the mold opening process. The optimum MOMIM PP/PTFE foam fabricated possesses a high cell orientation angle close to 90° and a large cell aspect ratio of 5.3, which reached a 34.37 % increase in tensile strength and a 73.08 % increase in impact strength owing to the synergetic effects of the PTFE network and the highly oriented fine cell structure, which effectively dissipated the tensile stress and impact stress by cell wall twisting and folding deformation. Furthermore, the MOMIM PP/PTFE foam showed a significantly enhanced surface quality compared to the MIM foam due to the reduced dragging flow in MOMIM, which greatly hindered cell rupture on the foam surface. Therefore, this work provides insights into the MOMIM of polymer composites containing fibrous fillers and the enhancement of tensile properties, impact resistance, and surface quality of foam products.

Modelling and verification of the nickel electroforming process of a mechanical vane fit for Industry 4.0

In previous studies, the comprehensive scaling-up of nickel electroforming on a lab-scale rotating disk electrode (RDE) suggested that secondary current distribution could adequately simulate such a forming process. In this work, the use of a 3-D, time-dependent, secondary current distribution model, developed in COMSOL Multiphysics®, was examined to validate the nickel electroforming of an industrial mechanical vane, a low-tolerance part with a demanding thickness profile of great interest to the aerospace industry. A set of experiments were carried out in an industrial pilot tank with computations showing that the model can satisfactorily predict the experimental findings. In addition, these experiments revealed that the local applied current density was related to the surface appearance (shiny vs matt) of the electroform.Simulations of the process at applied current densities ≤5A/dm2 satisfactorily predicted the experimentally observed thickness distribution while, simulations of the process at applied current densities ≥5A/dm2 underpredicted the experimentally achieved thicknesses. Nevertheless, it is proposed that the model can be used for either quantitative or qualitative studies, respectively, depending on the required operating current density on a case-by-case basis. Scanning electron microscopy was used to determine the microstructure of the electroforms and determine the purity of nickel (i.e., if nickel oxide is formed), with imaging suggesting that pyramid-shaped nickel particles evolve during deposition. Another interesting observation revealed a periodicity in the deposit's growth mechanism which leads to “necklace”-like deposit layers at the areas where the electroforms presented the highest thickness.

How obliquity has differently shaped Pluto’s and Triton’s landscapes and climates

Triton and Pluto are believed to share a common origin, both forming initially in the Kuiper Belt but Triton being later captured by Neptune. Both objects display similar sizes, densities, and atmospheric and surface ice composition, with the presence of volatile ices N2, CH4, and CO. Yet their appearance, including their surface albedo and ice distribution strongly differ. What can explain these different appearances? A first disparity is that Triton is experiencing significant tidal heating due to its orbit around Neptune, with subsequent resurfacing and a relatively flat surface, while Pluto is not tidally activated and displays a pronounced topography. Here we present long-term volatile transport simulations of Pluto and Triton, using the same initial conditions and volatile inventory, but with the known orbit and rotation of each object. The model reproduces, to first order, the observed volatile ice surface distribution on Pluto and Triton. Our results unambiguously demonstrate that obliquity is the main driver of the differences in surface appearance and in climate properties on Pluto and Triton, and give further support to the hypothesis that both objects had a common origin followed by a different dynamical history.

Musical Instruments and Palimpsestic Identity

ABSTRACT Palimpsests are conventionally understood to be manuscripts that have been reused or recycled, with traces of earlier inscriptions identifiable under later writings. Metaphorically, the term connotes ideas about reading off meanings, references or signs that remain recorded below surface appearance. Here I consider the palimpsestic nature of musical instruments, drawing extensively on the literary typology set out by Gérard Genette in his 1997 work Palimpsests: Literature in the Second Degree. Ultimately, I consider how any musical instrument is shadowed by a past that may or may not be visible through its morphology and/or surface ornamentation.

Improved EMI Shielding Behavior of Barium Ferrite Coated Carbon Fibers in Low‐Density Polyethylene Composites with an Optimized Electroless Coating Process

AbstractThis study describes using carbon fibers coated with magnetic material as a filler in polyethylene for EMI shielding. It investigates how to utilize barium ferrite (BaFeO3) as a conducting filler in a polyethylene matrix by optimizing the conditions for its electroless deposition onto carbon fibers. Various polymer nanocomposite samples were prepared using varying concentrations of BFO@CF. Scanning electron microscopy is used to assess the surface appearance of the composite and the distribution of BFO@CF within the polymer matrix. Including MWCNT/graphene nanoplatelets exhibit superior shielding properties, and the polymer composite with the BFO@CF demonstrates enhanced mechanical properties. The 8.2 to 12.4 GHz frequency range is used to study the EMI shielding properties. For the composition ratio of LDPE: MWCNT: GNP: BFO@CF (50 : 5 : 47.5 : 2.5), a maximum shielding of 67 dB was attained. After BFO@CF was added to the matrix, the absorption mechanism rather than the reflection mechanism dominated the shielding mechanism. A thorough evaluation and discussion of the shielding mechanism and parameters are presented.

Molecular weight insight into critical component contributing to reverse osmosis membrane fouling in wastewater reclamation

Molecular weight (MW) of organics was one of the important factors influencing membrane fouling propensity. This study identified critical foulants of reverse osmosis (RO) membranes in reclaimed water by MW fractionation. MW > 10 kDa component was identified as the critical fouling contributor (CFC) in secondary effluent (SE), which accounted for only 13 ± 5% of dissolved organic carbon (DOC) but contributed to 86 ± 11% of flux decline. Throughout 12-month monitoring, SE and MW > 10 kDa component showed a similar fouling variation tendency: apparently higher fouling potential in winter and lower in summer, while MW < 10 kDa component presented minor fouling changes. Morphology of membrane fouled by CFC characterized a smooth and thick foulant layer on membrane surface. CFC was mainly composed of proteins and polysaccharides, and a protein-polysaccharide-protein “sandwich” fouling layer structure was preferentially formed on membrane surface. extended Derjaguin–Landau-Verwey–Overbeek (xDLVO) analysis demonstrated that strong attractive interactions between CFC and membrane surface dominated the fouling process. Furthermore, computational fluid dynamics (CFD) simulation revealed strong filtration resistance of CFC, confirming its significant fouling potential. Dual effects including attractive interactions and advantageous ridge-and-valley surface appearance accounted for the significant fouling propensity of MW > 10 kDa component and glean valuable insights into RO fouling mechanisms of reclaimed water in practical application.

Synthesis of biocompatible Ti-6Al-4V composite reinforced with ZrO2 and bioceramic produced by powder metallurgy: Morphological, structural, and biocompatibility analysis.

In this experimental study, the initial phase involved preparing composite structures with various mix ratios using the Ti-6Al-4V alloy, widely used in clinical applications, in conjunction with ZrO2 and hydroxyapatite (HA) synthesized via the precipitation method, employing powder metallurgy techniques. Subsequently, the microstructures of the resultant hybrid composite materials were imaged, and x-ray diffraction (XRD) phase analyses were conducted. In the final phase of the experimental work, tests were performed to determine the biocompatibility properties of the hybrid composites. For this purpose, cytotoxicity and genotoxicity assays were carried out. The tests and examinations revealed that structures compatible both morphologically and elementally were obtained with no phase transformations that could disrupt the structure. The incorporation of ZrO2 into the Ti-6Al-4V alloy was observed to enhance cell viability values. The value of 98.25 ± 0.42 obtained by adding 20% ZrO2 gave the highest cell viability result. The addition of HA into the hybrid structures further increased the cell viability values by approximately 10%. All viability values for both HA-added and HA-free groups were obtained above the 70% viability level defined in the standard. According to the genotoxicity test results, the highest cytokinesis-block proliferation index values were obtained as 1.666 and 0.620 in structures containing 20% ZrO2 and 10% ZrO2 + 10% HA, respectively. Remarkably, all fabricated composite and hybrid composite materials surpassed established biocompatibility standards and exhibited nontoxic and nongenotoxic properties. This comprehensive study contributes vital insights for future biomechanical and other in vitro and in vivo experiments, as it meticulously addresses fundamental characterization parameters crucial for medical device development. RESEARCH HIGHLIGHTS: Support of optimum doping rates ions on hybrid composites and concentrations. Development of uniform surface appearance and distributions/orientations of microcrystals on ceramic compounds Improvement of cell viability and desired increase in biocompatibility with the doping of HA.

Effect of particle size distribution on the properties of celsian based glazes

AbstractThe microstructure and surface properties of ceramic glaze are influenced by chemical composition, particle size distribution, glaze application conditions, and firing parameters. This study specifically focused on the influence of glaze particle size distribution on the thermal behavior, microstructure, and surface appearance of barium frit based ceramic glaze in the floor tile firing process. The investigation involved examining the impact of four distinct particle size dimensions (d50: 5.7 μm, 6.8 μm, 7.5 μm, 10.9 μm) on the glaze properties by using hot stage microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), color and gloss measurements. The studies indicated that celsian is the dominant phase in the glaze structure. The sintering and softening temperatures of glazes decreased with the increase of milling time. A decrease in the particle size of the glaze slurry increased the whiteness index. As the average particle size (d50) of the glaze decreased, the number of crystals was also increased. The investigation results also suggested a relation between specular reflection and milling time. As the milling time extended, there was a corresponding increase in the magnitude of glossiness.