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Thermo mechanical analyses and characterizations of TiNiCu shape memory alloy structures developed by laser additive manufacturing
摘要： Three di?erent compositions of TiNiCu (Ti50Ni (50?x) Cux (x = 10, 20 and 30)) shape memory alloys (SMA) were developed using an intelligent manufacturing technique of laser additive manufacturing (LAM). Based on a numerical analysis the nature and amount of residual stress ?ow was predicted. By implementing ?nite element method (FEM) with Gaussian distributed volumetric heat source, the deposition process was simulated. The numerical and experimental analyses were at par with each other. The developed samples were subjected to several characterizations in order to determine the best among them. Scanning electron microscopy (SEM), atomic force microscopy (AFM), were used to study the surface morphology of the samples. The mechanical properties were studied using micro-hardness test and compression test. X-Ray di?raction (XRD) was deployed to investigate the crystalline nature of the samples. The phase transformation ability of the samples were determined by di?erential scanning calorimetry (DSC). The SEM revealed the deposition of all three samples to be homogeneous. The AFM results showed the grain size of TiNiCu10 to be 20.12 nm, the smallest among the samples. The micro-hardness and ultimate strength of TiNiCu10 was found to be 242 VHN and MPa respectively. XRD reveals the presence of three step transformation for TiNiCu20 sample. From the results, LAM process was considered as a successful methodology in developing TiNiCu bulk SMA structures. The properties of laser additive manufactured TiNiCu10 was found to be the best among the developed samples.
关键词： DSC,TiNiCu,SEM,XRD,Laser additive manufacturing,Shape memory alloy
更新于2025-09-16 10:30:52
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Effect of Ultrasonic Nanocrystal Surface Modification on the Microstructure and Martensitic Transformation of Selective Laser Melted Nitinol
摘要： Nitinol has significant potential for biomedical and actuating-sensing devices, thanks to its functional properties. The use of selective laser melting (SLM) with Nitinol powder can promote novel applications aimed to produce 3D complex parts with integrated functional performances. As the final step of the production route, finishing processing needs to be investigated both for the optimization of the surface morphology and the limit alteration of the Nitinol functional properties. In this work, the effect of an advanced method of surface modification, ultrasonic nanocrystal surface modification (UNSM), on the martensitic transformation and microstructure of SLM built Ni50.8Ti49.2 (at.%) was investigated. Scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry indicated that the UNSM process can generate stress-induced martensite, at least partially suppressing the martensitic transformation. The microhardness profile indicates that the UNSM process can affect the mechanical properties of the SLMed Nitinol sample in a range of up to approximately 750 μm in depth from the upper surface, while electron backscatter diffraction analysis highlighted that the initial austenitic phase was modified within a depth below 200 μm from the UNSMed surface.
关键词： NiTi,ultrasonic nano-crystal surface modification,EBSD,XRD,selective laser melting,microstructure
更新于2025-09-16 10:30:52
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Effect of organic dyes and polypyrrole on the efficiency of dye-sensitized solar cells
摘要： Polypyrrole films were coated on conductive glass by electrochemical deposition (alternative current of direct process). They were then used as the dye-synthesized solar cell counter electron electrodes. Scanning electron microscopy revealed that polypyrrole forms a nanoparticle like structure on the conductive glass. In the present study, two new organic dyes based on aniline and substituted 5-Nitrosalicylaldehyde with aniline were prepared and used and sensitizes in dye-sensitized solar cells. These dyes in solution and on a nano-anatase v2o5 substrate were investigated. Additionally, oxidation potential measurement were also carried out. Finally, dye-sensitized solar cells were fabricated to determine and conversion efficiency of each dye.
关键词： FESEM,Cyclic Voltammetry,FT-IR,Dye-sensitized solar cells,UV Spectroscopy,XRD,Nitrosalicylaldehyde-aniline
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE Regional Symposium on Micro and Nanoelectronics (RSM) - Genting Highland, Pahang, Malaysia (2019.8.21-2019.8.23)] 2019 IEEE Regional Symposium on Micro and Nanoelectronics (RSM) - CZTS Growth for Solar Cell Application by Electrochemical Deposition: pH Effect
摘要： Electrochemical deposition method has been widely used due to its advantages in stoichiometry control, large area growth, easy to form nano-structures, being low coast, possible formation of homogeneous thin films. In this study, Cu2ZnSnS4 (CZTS) thin films were deposited on ITO substrates by using single step electrodeposition method. CZTS absorber layers have been tried to be obtained at four different pH values of 4.70, 5.10, 5.70 and 6.23. Trisodium citrate was used as a complexing agent for co-electrodeposition. CZTS thin films were annealed for recrystallization in stoichiometric kesterite structure after deposition at 580 °C in sulfur powder and N2 atmosphere for 60 min. The structural, morphological and optical properties of CZTS thin films have been investigated by using X-ray diffraction (XRD), optical absorption techniques, scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy measurements. Diffraction peaks observed at 28.53°, 37.02°, 47.33°, 56.17°, 69.23° and 76.44° correspond to diffraction of (112), (202), (220), (312), (008) and (332) planes of CZTS films deposited in solution with pH 5.7, respectively. Thin films grown at other pH values, there are peaks observed from the secondary phases. CZTS films grown at pH: 5.7 has shown three Raman modes with a strong peak at 326 cm-1 and two weak peaks at 284 cm-1 and 367 cm-1, which are not visible in other films. These peaks are due to the kesterite CZTS structure present in CZTS films and well compatible with CZTS Raman peaks.
关键词： XRD and Raman,electrochemical deposition,CZTS
更新于2025-09-16 10:30:52
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Influence of dopant concentration on the electronic band gap energy of Yb-ZrSe <sub/>2</sub> thin films for photovoltaic application via electrochemical deposition technique
摘要： This research focus on the Influence of Dopant Concentration on Polycrystalline Ytterbium-doped ZrSe (Yb-ZrSe) material for possible photovoltaic application using the electrochemical deposition method. The cationic precursor was an aqueous solution of 0.01 mol ZrOCl2.8H2O while the anionic precursor was 0.15 mol selenium was prepared by dissolving with 5 ml of Hydrochloric acid (HCl), and then 0.05 mol Yb (NO3)3.5H2O was used as the dopant. The films were characterized using UV-1800 Visible Spectrophotometer, Bruker D8 Advance x-ray diffractometer with Cu Kα line (λ = 1.54056 ?) in 2θ range from 10°–90°and Scanning Electron Microscopy. X-ray diffraction (XRD) of the deposited films on FTO substrate studies reveals that films are polycrystalline by exhibiting diffraction peaks at (111), (200), (200) and (210) corresponds to the following angle (27.00°), (38.01°), (46.02°), (66.02°). (SEM) revealed that the grain size was uniformly distributed on the surface of the substrate. The optical band gap energy 1.57 eV was obtained.
关键词： XRD,optical properties,Yb doped ZrSe,ECD,SEM
更新于2025-09-16 10:30:52
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Natural Dyes Extracted from Fruits of Phyllanthus reticulatus as Sensitizers in ZnO Nanorods Based Dye Sensitized Solar Cells
摘要： DSSCs are a promising class of photovoltaic cells with the capability of generating green energy at low production cost since no expensive equipment is required in their fabrication. Zinc oxide (ZnO) nanorods were synthesized by hydrothermal method and their perfomance as photoanodes in dye-sensitized solar cells (DSSCs) employing I-/I3- as electrolyte and the dye extracts from fruits of Phyllanthus reticulatus as sensitizers was analyzed. the structural and surface characterization of the ZnO nanorods were accomplished using X- ray diffraction (XRD) analysis and high resolution scanning electron microscopy (HRSEM). XRD results revealed that the synthesized ZnO material exhibited hexagonal crystal structure which was found to be highly stable and crystallite. The dielectric properties of the ZnO nanorods were analyzed. The dye extracts were subjected to UV-Visible absorption spectroscopy analysis. The short-circuit photocurrent, the open-circuit photovoltage, and the power conversion efficiency of DSSC were measured using J-V measurement system.
关键词： Phyllanthus reticulatus,DSSC,XRD,HRSEM,ZnO nanorods
更新于2025-09-16 10:30:52
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Spectroscopic studies on Cr3+ doped ZnCdO nanostructures for optoelectronic device application
摘要： Cr3+ ion doped ZnCdO nanopowder was synthesized by chemical solution method. Structural (X-ray di?raction, surface morphology and energy dispersion), di?erent spectroscopic studies like FT-IR, EPR, Optical and PL were performed on the prepared nanopowders. From the XRD pattern, it was con?rmed that the crystalline size of the nanopowder was at nanoscale range. The morphological surface of the powder was analyzed by SEM. FT-IR showed the trademark assimilation groups identi?ed with the metal oxides and additionally other natural particles. EPR spectrum exhibited characteristic Cr3+ ion resonance signal at g = 1.98. By connecting EPR and optical information, the holding parameters have been resolved. From the optical absorption studies, the assimilation groups are assessed. Photoluminescence studies showed that the out?ow groups are in UV and blue area. These parameters recommended that Cr3+ ions are in octahedral site symmetry with covalent bonding nature.
关键词： Cr3+ ion doped ZnCdO nanopowder,EPR,FTIR,XRD,Optical,PL
更新于2025-09-12 10:27:22
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Structural characterization of Argania spinosa Moroccan wooden artifacts during natural degradation progress using infrared spectroscopy (ATR-FTIR) and X-Ray diffraction (XRD)
摘要： The present work is focused on spectroscopic study of four samples of Argan wooden artifact pertaining to the 17th, 18th, 20th and 21st centuries. The objective is to characterize their unknown structures by the study of their non degraded parts and to investigate changes occurred in their degraded parts due to the natural degradation process. Attenuated total re?ectance Fourier transform infrared spectroscopy gauges the presence of many functional groups related to cellulose I and/or II (OH, C–O–C and –CH2), hemicelluloses (particularly C?O (cid:2)1), and lignin (OH phenolic, Car-O and C?Car) and provides qualitative information on the state of wood alteration by informing on the evolution of new former C?O bands. The degree of conversion to carbonyl group, especially quinone or p-quinone at 1650 cm (cid:2)1, is correlated to lignin degradation, while the absence of the C?O acetoxy absorption is ascribable to occurred deterioration in hemicelluloses, and (cid:2)1. X-ray diffraction determines the presence of two forms of cellulose; amorphous cellulose at 18.5(cid:3) 2θ and predominant crystalline cellulose Iβ at 2θ ? 22.6(cid:3) which characterized by an intense peak. The decrease of crystallinity index values con?rms the deterioration level and obvious changes in crystallinity level. However, the microcrystalline structure appears unaltered because no signi?cant changes were observed for calculated cristallite seize. The obtained results depend on the prolonged time of ageing, natural deterioration phenomena, and wood part (internal or external) that is exposed to degradation. The combination of these two methods is useful for an accurate estimation of the degradation level of argan wood.
关键词： Chemistry,Argan wood artifact,XRD,Analytical chemistry,Natural product chemistry,Materials Chemistry,Natural degradation,Archaeology,ATR-FTIR spectroscopy,Crystallinity,Lignocelluloses,Structural characterization,Materials Science,Organic chemistry
更新于2025-09-12 10:27:22
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Development of a Hybrid Chitosan- and Niacinamide-Coupled ZnO Nanoparticle Composite for Sun Protection Application
摘要： Zinc oxide nanoparticles (ZnO) have long been utilized as UV-protective sunscreen components due to their high durability and lower skin irritation while maintaining capability for blocking UV rays. However, the dispersal and transparency properties of ZnO need to be enhanced in order to improve the capacity for creating effective sunscreen through control of the physiochemical properties of ZnO. In this study, chitosan or niacinamide, which are suitable functional cosmetic compounds and effective skin lightening agents, are combined with ZnO for the development of better UV-protective products. Each biocompatible coating material is individually attached on its surface after the synthesis of ZnO. The size is 70 nm using the sol-gel method. Their morphology and chemical structure are characterized by FT-IR, XRD, SEM, TEM, TGA, and zeta potential. The results indicate that approximately 50% of chitosan and 5% niacinamide were coated on the ZnO. To confirm the capacity of each surface-coated ZnO with chitosan and niacinamide as a sunscreen, we measured their transmission, reflectance, and sun protection factor (SPF) using a UV spectrophotometer and SPF. As a result, the niacinamide-coated ZnO shows remarkably lower transmission and high reflectance against UV rays than that of bare ZnO and chitosan-coated ZnO. Furthermore, niacinamide-coated ZnO exhibits great lightening effects. Consequently, these results demonstrate that niacinamide coating is highly effective for the production of sunscreen emulsions.
关键词： Zinc oxide nanoparticles,TEM,FT-IR,SEM,XRD,UV-protective sunscreen,TGA,chitosan,SPF,sol-gel method,zeta potential,niacinamide,sun protection factor
更新于2025-09-12 10:27:22
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Wear Tribo-Performances of Laser Cladding Colmonoy-6 and Stellite-6 Micron Layers on Stainless Steel 304 Using Yb:YAG Disk Laser
摘要： Stainless steel material has been widely used in aeronautical, chemical and nuclear industries due to good corrosion resistance. However, the material has less hardness and wear resistance. In this study, two various depositions namely Colmonoy-6 and Stellite-6 have produced on 304 Stainless steel. Besides, the coating was examined to reveal their metallurgical, mechanical and tribological properties. In addition, wear mechanism, wear debris and roughness averages were studied. The outcomes indicate that both coatings show with dendrite structure due to rapid cooling rates. Hardness of the clad surface has improved than substrate material. The results of friction coefficient of specimen with Colmonoy-6 is lower than that of specimens Stellite-6 and substrate. Also, wear resistance of Colmonoy-6 has increased 49 times than substrate sample, which reveals that Colmonoy-6 laser cladding plays role on wear resistance. Adhesive and abrasive are the major wear mechanisms in the present study.
关键词： Wear debris,Microstructure,Stainless steel 304,Roughness,Wear performance,XRD,Laser cladding,Hardness
更新于2025-09-12 10:27:22