Energy Dispersive Spectrometer Research Articles

Effect of phosphorus-doping on ternesite: Structure, thermal stability and hydration

The successful synthesis of the solid solution Ca5(Si1-x/2O4)2S1-x/2PxO4 (C5S2S̅Px, x = 0.05, 0.10, 0.15, 0.20) was confirmed through analysis of X-ray diffraction and energy dispersive spectrometer data. Rietveld refinement revealed that the purity of ternesite can reach up to 99.42 % at a doping concentration of 5 %. Furthermore, changes in X-ray diffraction peaks and morphology suggest a shift in the preferred growth direction of crystallites as a result of the introduction of impurity element. The incorporation of P elements in C5S2S̅Px not only effectively reduces weight loss under high-temperature conditions but also elevates the temperature at which decomposition occurs. Isothermal calorimetry data indicates that C5S2S̅Px-CSA samples display higher cumulative heat release compared to C5S2S̅–CSA. Furthermore, the presence of C5S2S̅P0.20 accelerates the hydration kinetics of CSA cement by hindering ettringite formation. Moreover, varying levels of phosphorus doping in C5S2S̅Px have resulted in enhanced compressive strength at various ages of CSA cement maturation.

Facile synthesis of RGO/TiO2 heterojunction on SiNWs on Si chip for near infrared detector

Here, a ternary nanostructure-based heterojunction was developed for the detection of infrared (IR) radiation in near wavelength range. During materials synthesis process, silicon nanowires (SiNWs) were developed using metal assisted chemical etching (MACE) technique whereas reduced graphene oxide (RGO) sheets and TiO2 nanoparticles were synthesized by chemical vapour deposition (CVD) and solvothermal method, respectively. Thereafter, RGO/TiO2 nanostructure was deposited over SiNWs to form a heterojunction. To analyse the stoichiometry, morphology, and internal structure, various characterization techniques were performed such as scanning electron microscope (SEM), transmission electron microscope (TEM), Energy dispersive spectrometer (EDS), X-Ray Diffractometer (XRD), UV–Vis spectrophotometer and X-Ray Photoelectron Spectrometer (XPS). The RGO/TiO2@SiNWs nanostructure-based heterojunction was used for the detection of near IR radiation where the responsivity (R) was found to be 17.22 × 10−3 A/W and detectivity (D) was measured to be 0.23 × 1011 Jones with response time < 1 s and recovery time < 3 s. These results were found comparatively better than pristine RGO@Si and RGO@SiNWs nanostructure-based sensors used for the near IR detection under same conditions. The photocurrent response was also recorded with 5 ON/OFF cycles which depicted a good reproducibility of the prepared detector. Hence, the SiNWs on Si chip based highly sensitive and selective photodetector can be used to set a new milestone for various near IR applications.

Forensic characteristics of damage caused by spherical striking elements of GMLRS MLRS type ammunition

ABSTRACT The study of forensic aspects of blast injury caused by the damaging elements of GMLRS-type MLRS ammunition is currently of particular interest due to the high frequency of occurrence and the lack of diagnostic criteria. BACKGROUND: to study the morphological features of damage caused by spherical submunitions of the GMLRS type ammunition for MLRS in conjunction with electron microscopy and elemental analysis of the submunitions. AIM: The study was carried out using visual, metric methods, X-ray examination, scanning electron microscopy with energy-dispersive X-ray analysis using a Hitachi FlexSem1000 II scanning electron microscope and a Bruker Quantax 80 energy-dispersive X-ray spectrometer. RESULTS: An analysis of the morphological features of damage caused by the damaging elements of GMLRS type ammunition for MLRS was carried out. Scanning electron microscopy and energy dispersive analysis made it possible to identify the characteristic chemical composition of the damaging elements. X-ray examination of the bodies of the dead reveals characteristic round shadows of metallic density. CONCLUSION: The established morphological features of external and internal damage caused by spherical damaging elements of ammunition of the GMLRS MLRS type, in combination with electron microscopy and elemental analysis, make it possible to establish with high reliability the damage to the human body caused by the striking elements of the specified type of ammunition when solving such expert problems.

Predictive Modelling and Optimization of the Mechanical Properties of Laser-Coated NB/SiC/Ni Welds Using an ANFIS

In the present work, predictive modelling and optimization with the adaptive network based fuzzy inference system (ANFIS) modelling of the mechanical properties of laser-coated NB/SiC/Ni welds was studied based on the Taguchi design by laser cladding. An ANFIS model based on a Sugeno type fuzzy inference system was developed for predicting the hardness properties of SiC/BN/Ni welds by laser cladding with experimental data required for network training and prediction. Based on analysis of variance, three important factors were taken as inputs for the fuzzy logic inferences, while the hardness properties were taken as the output of the ANFIS. The microstructure of welds was analysed using scanning electron microscopy with an energy-dispersive X-Ray spectrometer. Highly developed leaf-like dendrites and eutectic crystals were found in some areas of the melting zone for the BN/SiC/Ni weld, which was significantly hardened. The ANFIS model based on Taguchi’s design provides a better pattern of response because the predicted and experimental values were highly similar. As a result, a satisfactory result was achieved between the predicted and experimental values of hardness in laser-coated NB/SiC/Ni welds, whereby the success and validity of the method was verified.

Corrosion Behavior of Ni-Cr Alloys with Different Cr Contents in NaCl-KCl-MgCl2.

This study investigates the corrosion behavior of Ni-Cr binary alloys, including Ni-10Cr, Ni-15Cr, Ni-20Cr, Ni-25Cr, and Ni-30Cr, in a NaCl-KCl-MgCl2 molten salt mixture through gravimetric analysis. Corrosion tests were conducted at 700 °C, with the maximum immersion time reaching up to 100 h. The corrosion rate was determined by measuring the mass loss of the specimens at various time intervals. Verifying corrosion rates by combining mass loss results with the determination of element dissolution in molten salts using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Detailed examinations of the corrosion products and morphology were conducted using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Micro-area elemental analysis on the corroded surfaces was performed using an energy dispersive spectrometer (EDS), and the elemental distribution across the corrosion cross-sections was mapped. The results indicate that alloys with lower Cr content exhibit superior corrosion resistance in the NaCl-KCl-MgCl2 molten salt under an argon atmosphere compared to those with higher Cr content; no corrosion products were retained on the surfaces of the lower Cr alloys (Ni-10Cr, Ni-15Cr). For the higher Cr alloys (Ni-20Cr, Ni-25Cr, Ni-30Cr), after 20 h of corrosion, a protective layer was observed in certain areas. The formation of a stable Cr2O3 layer in the initial stages of corrosion for high-Cr content alloys, which reacts with MgO in the molten salt to form a stable MgCr2O4 spinel structure, provides additional protection for the alloys. However, over time, even under argon protection, the MgCr2O4 protective layer gradually degrades due to chloride ion infiltration and chemical reactions at high temperatures. Further analysis revealed that chloride ions play a pivotal role in the corrosion process, not only facilitating the destruction of the Cr2O3 layer on the alloy surfaces but also possibly accelerating the corrosion of the metallic matrix through electrochemical reactions. In conclusion, the corrosion behavior of Ni-Cr alloys in the NaCl-KCl-MgCl2 molten salt environment is influenced by a combination of factors, including Cr content, chloride ion activity, and the formation and degradation of protective layers. This study not only provides new insights into the corrosion resistance of Ni-Cr alloys in high-temperature molten salt environments but also offers significant theoretical support for the design and optimization of corrosion-resistant alloy materials.

Investigation of corrosion resistance and interfacial bonding properties of silver/silicone zinc-rich coating/substrate system in marine environment

This paper aims to study the corrosion resistance and interfacial bonding properties of the silver zinc-rich coating/substrate system and silicone zinc-rich coating/substrate system. The actual working state of the system in marine environment was simulated by the coupled effects of corrosion and pre-stretching. Scanning electron microscope (SEM) with an energy dispersive X-ray spectrometer (EDS) was used in corrosion test to analyze the surface morphology and corrosion products. Meanwhile, the degradation degree of the corrosion resistance was investigated based on the electrochemical impedance spectroscopy (EIS) and water absorption rate. Three-point bending test and tensile test combined with digital image correlation (DIC) were performed to evaluate the interfacial bonding properties of these two systems based on the elastic modulus and critical cracking strain. Results show that the dense accumulation of aluminum and zinc powders makes the silver zinc-rich coating have higher corrosion resistance compared to the silicone zinc-rich coating. The combined effects of corrosion and pre-stretching on the fracture toughness of silicone zinc-rich coating are larger than that of the silver zinc-rich coating. The interfacial bonding properties of the coating/substrate systems gradually degrade as the pre-stretching load approaches the critical cracking load of the coating.

Synergistic effect of ZnO/Ag2O@g-C3N4 based nanocomposites embedded in carrageenan matrix for dye degradation in water

This research achieved success by synthesizing innovative nanocomposite composed of zinc oxide (ZnO), graphitic carbon nitride (g-C3N4) and silver oxide (Ag2O) nanomaterials incorporated into a carrageenan matrix, thus creating an environmentally friendly and stable support structure. The synthesis process involved hydrothermal and chemical precipitation methods to create photocatalytic g-C3N4, ZnO, and Ag2O nanocomposites. The success is evident through the characterization results, which unveiled distinctive peaks corresponding to Zn–O (590-404 cm−1) and Ag–O (2072 cm−1) stretching in the Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses, conclusively confirming the successful synthesis of g-C3N4, ZnO, Ag2O, and their respective nanocomposites. Further validation through a scanning electron microscope coupled with an energy dispersive spectrometer (SEM-EDX) and elemental mapping affirmed the presence of Zn, O, Ag, C, and N. Additionally, transmission electron microscope (TEM) imaging unveiled the nanosheet morphology of g-C3N4, the nanorod structure of ZnO, and the spherical form of Ag2O nanomaterials. ZnO and Ag2O nanomaterials demonstrated a consistent 10–20 nm size range. To underscore their ability to harness visible light, the nanomaterials were excited at 380 nm, emitting visible light emission within the 400–450 nm range. The synthesized nanocomposites showcased outstanding adsorption and photocatalytic properties, achieving efficiency ranging from 80 % to 98 %, attributed to the synergistic interactions between the various components. These findings culminate in a confirmation of the research's success, validating the exceptional potential of these nanocomposites for various applications.

Green and sustainable degradation of ofloxacin in Fe3O4/clinoptilolite electro-Fenton system under neutral condition

BackgroundIn order to overcome the drawbacks of the pH value adjustment and Fe2+addition of traditional electro-Fenton in refractory organic wastewater treatment, we set up an electro-Fence system (FCC-EF) with multiple functions of adsorption, catalysis, and green regeneration for efficient and green degradation of ofloxacin (OFLO) wastewater under neutral condition. MethodsThe Fe3O4/clinoptilolite catalyst with adsorption function was prepared by hydrothermal synthesis method, and then characterized by energy dispersive spectrometer (EDS), transmission electron microscopy (TEM) and X-ray Diffractometer (XRD). The Fe3O4/clinoptilolite's chemical composition and oxidation state was investigated by X-ray photoelectron spectros (XPS). The degradation of OFLO and the total organic carbon (TOC) were determined through HPLC and a TOC analyzer, respectively. FindingsThe results indicate that in multi-cycle operation under current density of 6 mA·cm−2 and pH = 7, FCC-EF has a 100 % removal rate for OFLO and 80.4 ± 0.2 % removal rate for TOC at 165 min, while no iron ions are detected. The internal cycling of Fe3+/Fe2+ within Fe3O4 crystals is performed in FCC-EF. The green regeneration of Fe3O4/clinoptilolite and the efficient degradation of OFLO in multi-cycle operation could be simultaneously achieved under neutral condition.

Underwater dissimilar friction stir lap welding of aluminum alloy and CFRTP

Underwater dissimilar friction stir lap welding of aluminum alloy and CFRTP

A high-resolution characterization of surface film formed on alloys 800 and 690 exposed to chloride and thiosulfate-containing solution at 300°C

Purpose This paper aims to characterize the surface film formed on Alloys 800 and 690 in chloride and thiosulfate-containing solution at 300°C. Design/methodology/approach Alloy 800 and 690 were immersed in chloride and thiosulfate-containing solution at 300°C up to five days, and then the surface film was analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray spectrometers (EDX). Findings Through static immersion experiments in a high-temperature and high-pressure water environment, the alloy samples covered by surface film after five days of immersion were obtained. The morphology of the surface film was characterized at both horizontal and cross-sectional scales using SEM and focused ion beam-TEM techniques. It was observed that due to the influence of the quartz lining, the surface film primarily exhibited a bilayered structure. The first layer contained a significant amount of SiO2, with a higher content of metal hydroxides compared to metal oxides. The second layer was predominantly composed of Fe, Ni and Cr, with a higher content of metal oxides compared to metal hydroxides. Originality/value The results showed that the materials of the lining of the autoclave could significantly influence the film composition of the tested material, which should be paid attention when analyzing the corrosion mechanism at high temperature.

Synthesis of Magnetic Attapulgite Nanoparticles Via a Novel Surface Covalent Reaction Method and its Application in the Magnetic Solid Phase Extraction.

In this study, the attapulgite nanoparticle was immobilized on the surface of magnetic nanoparticle Fe3O4 via a novel surface covalent reaction method for the magnetic solid phase extraction (MSPE) for the first time. The surface covalent reaction method has the advantages of controllable steps, and can make the magnetic attapulgite nanoparticle (MANP) have good homogeneity and high stability. Field emission scanning electron microscopy, equipped with an energy dispersive spectrometer, Nitrogen adsorption BET, X-ray diffraction and Fourier transform infrared spectroscopy were applied to characterize the prepared MANP, confirming that the attapulgite nanoparticle could be effectively immobilized on the surface of magnetic nanoparticle Fe3O4 via covalent reactions. Under optimal conditions of the MSPE experiment based on the MANP, the limits of detection were found to be 10ng/mL for melamine and 3ng/mL for cyromazine with a relative standard deviation < 10% by a high-performance liquid chromatography system. Meanwhile, 0.1mg/mL melamine in milk and 0.1mg/mL cyromazine in cucumber can also be detected according to our MSPE procedure. More importantly, the MANP still has good magnetism and enrichment efficiency after several decades of use. These results showed that the MANP prepared by our method is a kind of promising material for the MSPE.

Visible-light-driven photocatalytic degradation of doxycycline using TiO2/g-C3N4/BIOCHAR catalyst

Abstract TiO2/g-C3N4/biochar (TCNBC) catalysts were prepared by the hydrolysis method for the photocatalytic degradation of doxycycline antibiotic (DC), with biochar obtained from the pyrolysis of Phragmites australis. The catalysts were examined using scanning electron microscope (SEM), transmission microscopy (TEM), energy dispersive X-ray spectrometer (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), and ultraviolet-visible diffuse reflectance spectroscopy (UV–Vis DRS) and nitrogen adsorption/desorption. The photocatalytic activity results showed that the TCNBC catalyst exhibited higher catalytic activity than pure TiO2 or g-C3N4. Its peak catalytic activity, achieving a decomposition efficiency of 91.93% and a mineralization efficiency of 81.50%, can be attributed to the synergistic effect of biochar, TiO2, and g-C3N4. Even after four cycles of use, the catalyst still maintained relatively high activity for the degradation of DC. The photocatalytic degradation efficiency of TCNBC decreased from 91.93% to 86.30% after four recycling events.&amp;#xD;

On the Methodology of the Quantitative Analysis of Fe–Cr–Mn–Mo–N–C Steels Reinforced with Oxide and Nitride Particles Using an Energy Dispersive X-Ray Fluorescence Spectrometer BRA-135F

On the Methodology of the Quantitative Analysis of Fe–Cr–Mn–Mo–N–C Steels Reinforced with Oxide and Nitride Particles Using an Energy Dispersive X-Ray Fluorescence Spectrometer BRA-135F

Synthesis of Copper Supported on Natural Rubber-derived Mesoporous Carbon/Silica Composite for Efficient Adsorption of Caffeine

Caffeine (CAF) removal from water resources is important because it is widely distributed and can be toxic to aquatic life. The copper supported on mesoporous carbon/silica composite (Cu/MCS) in this research was developed as a novel adsorbent to remove caffeine from aqueous solutions. The Cu/MCS material was prepared in two steps. The first step was the preparation of a precursor consisting of copper and natural rubber distributed inside a hexagonal mesoporous silica matrix (Cu/NR/HMS). Then, the composite was carbonized at high temperature under inert gas conditions to obtain Cu/MCS material. The amount of Cu loading in the MCS structure was studied. The Cu/MCS composites revealed a high level of copper distribution incorporated into the mesoporous carbon/silica framework as confirmed by Powder X-ray diffraction (XRD) and Scanning Electron Microscope and Energy Dispersive X-ray Spectrometer (SEM-EDS). The Cu/MCS materials possessed a high specific surface area (523–748 m2 g−1), large pore volume (0.80–0.86 cm3 g−1) and mesoporous diameter (3.07-3.30 nm). Fourier Transform Infrared Spectroscopy (FT-IR) and CHN analysis revealed a high amount of carbonaceous species dispersed in the Cu/MCS material. The Cu (0.010)/MCS, with copper loading of 1 mmol/g, revealed good properties for CAF removal when compared to other series of Cu/MCS adsorbents. Moreover, the Cu (0.010)/MCS composite exhibited the maximum adsorption capacity for CAF as 55.8 mg/g.

Exploring the improving role of MWCNTs on the electrochemical behavior of electrophoretically prepared Ti/nanoZnO metal oxide electrode: A comparative study

In recent years, a growing amount of attention has been paid to the investigation and modification of metal oxide anodes as a critical parameter in electrochemical removal. In this way, this research attempts to bring out an effective comparison between modified Ti/nanoZnO electrode by multi-walled carbon nanotubes (MWCNTs) and base Ti/nanoZnO electrode. The electrophoretic deposition (EPD) method was used to prepare electrodes. The morphological and chemical composition of the surface for both electrodes were obtained by using characterization tests including field emission scanning electron microscope - energy dispersive spectrometer (FESEM-EDS), elemental mapping, and X-ray diffraction (XRD). Furthermore, the electrochemical behavior of Ti/nanoZnO as well as Ti/nanoZnO-MWCNTs electrodes were compared using linear sweep voltammetry (LSV), chronopotentiometry (CP), and chronoamperometry (CA) analysis. In the final step, the chemical oxygen demand (COD) removal in addition to the decolorization rate of a dyes mixture was used to evaluate the electrochemical performance in the same conditions. Presented results in this study showed the importance of metal oxide anode modification by improved deposited coating properties of Ti/nanoZnO-MWCNTs electrode compared with base ZnO electrode.

Remediation of 3,4,3′,4′-tetrachlorobiphenyl (PCB77) contaminated soil via a fluidized bed dielectric barrier discharge

In this study, 3,4,3′,4′-tetrachlorobiphenyl (PCB77) contaminated soil was remediated by a fluidization bed dielectric barrier discharge (DBD) reactor and a fixed bed DBD reactor. The fluidized bed reactor could attain superior removal efficiency of PCB77 under same experimental parameters. In-situ discharge mode was more conducive to the degradation of PCB77 than ex-situ discharge mode due to short-lived active species existing in in-situ discharge. The influence of experimental parameters in the fluidized bed DBD reactor on the degradation of PCB77 were discussed such as electric features, gas features, soil features and initial PCB77 concentration. PCB77 removal efficiency in air discharge could reach 88.5 % after 8 min under the alkaline condition. Optical emission spectroscopy (OES) and quench tests showed that reactive oxygen species (ROS) and reactive nitrogen species (RNS) were generated in the discharge system and they both played a vital role in the degradation of PCB77. Scanning electron microscopy (SEM) results demonstrated that discharge had little effect on the morphology of soil particles. Energy dispersive spectrometer (EDS), ion chromatography (IC), and total organic carbon (TOC) results showed that the DBD could effectively mineralize and dechlorinate PCB77. The possible degradation pathway of PCB77 was inferred at the end based on the degradation products determined by gas chromatography–mass spectrometry (GC–MS).

Effect of tempering temperature on microstructure and mechanical properties of 4Cr13VTi steel

To optimize the tempering process of 40Cr13VTi steel containing V and Ti, the effect of tempering temperature on microstructure, precipitation, and properties of 40Cr13VTi stainless steel has been studied. Optical microscope (OM), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS) were used to analyze microstructure and precipitates. Tensile, impact, and hardness testing tests were performed to test the mechanical properties of 40Cr13VTi martensitic stainless steel. The research results indicate that as the increase of tempering temperature, the carbides precipitated gradually increase, and the shape gradually changes from particle to flake, which is consistent with the direction of the original martensite flat surface, and most of them concentrate at the martensite boundary. When the tempering temperature is 350°C, 40Cr13VTi martensitic stainless steel obtains the best comprehensive properties, strength, impact toughness (IT), and hardness which are 1360 MPa, 1717 MPa, 8.5 J/cm2, and 45.1 HRC respectively.

Characterizations and Solubility Profile of Novel Senary SiO2–CaO–Na2O-P2O5–CaF2–SrO Glass Structure Modified with Nb2O5

The solubility/degradability of bioactive glasses play crucial role in bone tissue engineering applications owing to the release of ions from their structure, which exert therapeutic effects on tissues. The present study evaluates the findings of a detailed investigation on the main features and solubility behaviors of newly formulated Nb incorporated glasses (Nb-BGs). New glass formulation in SiO2–CaO–Na2O–P2O5–CaF2–SrO–xNb2O5 (x: 0.0, 0.5, 1.0, and 1.5 mol. %) system was successfully synthesized by melt-quenching technique. Glass composition was verified with Energy Dispersive X-ray Fluorescence spectrometer analysis and its amorphous nature, functional groups of the matrix and morphological features were identified via X-Ray diffraction analyses, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscope analysis, respectively. Network connectivity (NC) of the Nb-BGs was assessed with respect to the role of Nb2O5 in the glass matrix as network former, modifier, or both. In order to evaluate the in vitro solubility of Nb-BGs, released concentrations of particular ions from the glass compositions were determined at certain time points and comprehensively discussed with several mathematical models such as zero-order, first-order, second-order, Higuchi, and Korsmeyer-Peppas for the first time. Results showed that the incorporation of Nb2O5 (up to 1.5 mol. %) increased the density, oxygen density as well as NC values of newly formulated glasses. Si, Na and Ca ions which play a main role in well-defined Hench’s mechanism followed mostly second-order release kinetics for all glasses in the mathematical models studied. When the Nb content increase (to 1.5 mol. %) in glass composition, the release mechanism of Si ion according to Korsmeyer-Peppas model shifts from the diffusion mechanism to an erosion-dominant release mechanism.

Facile synthesis of benzimidazole based mono- and bimetallic zeolitic imidazole frameworks for enhanced CO2 capture performance

Utilization of Zeolite imidazole frameworks (ZIFs) based membrane for Efficient CO2 capture is one of the most significant and advantageous methods to reduce the greenhouse gas quantity in the atmosphere. Here we report a simple room temperature synthesis of robust monometallic ZIF-7, ZIF-9 and bimetallic Zn2+ and Co2+ containing ZIFs to achieve five porous meterials, Zn100−xCox-ZIF (X = 0, 25, 50, 75 and 100). All the synthesized ZIFs are characterized through powder X-ray diffraction, thermogravimetric analysis (TGA), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) to examine the phase, texture, morphology, chemical state and surface area. The presence of metal in a specific ratio was examined through the Energy Dispersive X-ray Spectrometer (EDS). Incorporation of Cobalt into Zn containing ZIFs not only increases their thermal stability but also enhances their photophysical properties, thereby decreasing the optical band gap. Furthermore, bimetallic ZIFs exhibited higher specific surface area and CO2 uptake capacity than their parents monometallic counterparts. Specific surface area and CO2 uptake capacity of mono/ bimetallic ZIFs were studied at 298 K. The CO2 uptake of 1.83 cm3/g, 4.76 cm3/g, 6.26 cm3/g, 9.62 cm3/g, and 16.62 cm3/g for ZIF-7, ZIF-9, Zn100−xCox-ZIF (X = 25, 50 and 75), respectively, are obtained.

Microstructure and coloration mechanism of TC11 aerospace titanium alloy ultra-thin thermal oxide films

This study explores the microstructure and coloration mechanism of high-saturation structural colors in ultra-thin oxide films formed on TC11 aerospace titanium alloy near permissible engineering temperatures. Utilizing optical microscopy (OM), spectrophotometry, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), focused ion beam (FIB), transmission electron microscopy (TEM), and energy dispersive spectrometer (EDS), the optical properties, thickness, and microstructure of the oxide films were examined. The research posits a coloration theory grounded in zero-order Fabry-Pérot resonance-enhanced absorption. Key findings reveal a color transition in the oxide films from golden to light blue as oxidation conditions vary from 450 °C for 5 h to 550 °C for 60 h, with an average thickness ranging from 16.3 nm to 63.4 nm. Despite changes in oxidation conditions, the film's structure remains consistent and uniform. It predominantly consists of Brookite-type TiO2, TiO and Al2O3, with trace amounts of MoO2 and MoO3. The film's color is independent of its structural composition and instead related to its thickness, influencing the absorption wavelength per the Fabry-Pérot model, which closely matches the observed absorption wavelengths. Notably, oxidation acceleration between 30 and 60 h at 550 °C heralds the commencement of a deviation from the coloration mechanism of the oxide film based on the Fabry-Pérot cavity.